BritBike Forum

alloy barrels + 5 speeds A65 750 OIF 1971

Posted By: gavin eisler

alloy barrels + 5 speeds A65 750 OIF 1971 - 05/07/14 5:52 am

Hi there,
My 1971 Devimead lightning is due some TLC, the bike currently has not run for a few years and needs excavated from the back of a friends shed. It was running when it was put away but will need a new battery and carb cleaning at the very least.
This thread will be about small time resurrection , with a bonus feature of replacing the old worn Devimead 750 barrels with brand spanking new Alloy barrels supplied by John Hill.
The following pics are shots of the barrels in my secret underground layer.
The barrels were cleaned with a citrus based cleaner then blow dried.[Linked Image]
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Here they are posing in the turbine pit of Unit three, thats the reg ring and machine shaft in the cage[Linked Image]
All clean now
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Riding on a barra in the machine hall[Linked Image]
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 05/07/14 6:07 am

Next part,
The gasket needed the mounting holes enlarged , part 2 in the underground lair.
An amusing cupboard note the BSA mod
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Not a BSA cupboard
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Barrels pistons rings and gasket posing on the lifting beam beside U4[Linked Image]
The name plate details for U4 also made around the same time as the BSA but around 60 thousand times more powerful[Linked Image]
On the minus 26 level at the drill press with the Colchester student in the background
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Need drills, yes, but even with such choice the ones I needed were4 blunt, typical of shared tooling
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De burring the holes , spot the deliberate error.[Linked Image]
Gee it a wee bit file
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Job done, ready to go
[Linked Image].
Part 3 in a week or so.
Bye for now
Posted By: GrandPaul

Re: alloy barrels for 750 OIF 1971 - 05/07/14 8:09 am

That's too much. Very nifty.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 05/12/14 9:25 am

Part 3, checking ring end gaps ,
a quote from an interesting discussion on ring end gaps
"Now the ring gap deal. I don't have access to the kind of support data that I could throw at you six months ago. Its too bad - - but thats just the way it is.

Big second gaps work. We run them in most if not all OE applications no matter what the RPM. We ran them in Greg Andersen's Pro Stocker. We ran them in Moran's turbo stuff. And everything in between.

The original concept work was in math from a computer simulation series run on a Cray in Ann Arbor. This was followed up by OE dyno testing and development aimed at emissions and fuel mileage enhancement. You cannot sell an OE on a change of this magnitude without solid support. After the OE modeling showed an advantage we input the data from a then current Cup motor to see if it also applied to higher power, higher RPM applications. It did.

The reason for the testing was to gain an enhanced understanding of the ring and piston package as a dynamic sliding seal system - rather than as a bunch of parts. Old thinking was that the smaller the gap - the better. Since 2nd rings ran cooler we set the gaps smaller and thought that we were doing good things. For top rings we were right - as tight as you can without butting is the answer. But for second rings it was not true - - they function as a squeegee for oil moreso that anything else. By allowing blowby gasses to flow through the ring gap we were able to improve top ring sealing and add directional impetus to any scraped oil helping to send it back down to the sump."

I go this from a link posted somewhere on this site.

At home, on the kitchen table inserting a new ring and pushing it square with the piston,
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using a banana to back light the end gap.
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Gaps on all three check out at a tight ish 0.010",
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the manual ask for 8 - 13 thou, .A general rule for end gaps is 4 though per inch of bore, so about 12 thou by the general rule. So using the info above I am going to size the rings at 10 thou top and oil ring and 13 thou for the 2nd compression,.

Here you see the "top " mark on the compression ring against my claim form for Scottish ethnicity, this is not normally needed for end gap fitting but I want to add an element of mystery.
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The eagle eyed will note that this is post prandial ring measurement , salt , pepper, digestive biscuits and posh crisps accompany the barrels piston rings and a hovering magnetic pen I got at the Glasgow science centre.
Part 4 will follow with the bonus of a castrol R incense burner to set the correct mood.
Posted By: Adam M.

Re: alloy barrels for 750 OIF 1971 - 05/12/14 10:07 am

Hi Gavin, what pistons and rings do you use ?
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 05/12/14 10:45 am

Hi Adam, John kindly supplied the pistons , I think they are originally for a B44 , stamped 79 ( bore in mm ) on top with a casting mark 824 on the underside of the crown , they are 2nd hand and have very light scuffs on the thrust faces.
The rings are Italian "Gandini", supplied by MCA Birmingham, England,
The label says
Serie segmenti GPM, ( maybe for GPM pistons, they fit the pistons in the pic anyway))
Diam 79.00


They are cast iron with a one piece oil ring. Weighing 363 grammes each without the rings.

Compared to my old 750 "Omega" pistons they are slightly higher comp with a crown about 3 mm taller, but the gudgeon pin to ring lands are the same as the Omegas.
New piston, pin, plus rings on scale, 385 grammes
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Old worn Omega piston, pin and rings on scale 393 grammes
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Gandini ring box details
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Crown height differences a bit exagerrated note pins and rings are not co planar
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Rings married in slots , note extra meat above new piston top ring slot, sorry about the blurry shoy
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Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971, - 06/24/14 7:34 pm

A bit of background, I got this bike in 1981, it already had the end feed , big bore and close ratio box. It is my friend , weve had some good, great, bad and shitey times together, its gone up dirt tracks with TT100s and silly gears, and shown a lot of newer stuff the way home. Seen me through three SWMBO and never had the full strip restore.
Its gone through two sets of mudguards /fenders, stanchions seats and fuel tanks . ( Crashtastic , to a point).
I like its simple serviceability and the way the 1/2 x 7/16 ringer plus 2 Allen keys does all the top end work. Not BSAs best moment but a good rework like Hendrixs take on Hoochie Coochie man.

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the old bike up for surgery, this bike has never been restored, just worked on as required, it hasnt run for 11 years and has developed some patina

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got the tank off

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Balance pipe and rocker cover showing late 5/16 UNF rocker fasteners

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Carb rubber has split

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Tools for exhaust removal, slackened off the pinch clamps on the balance pipe and removed the rear footrests, the block of wood is bumped against the headers at the front mounts, the long brass drift is used to chivvy off the balance pipe, slowly slowly catchee monkee, I was dreading this, but it all came free with limited hassle. Woohoo.

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My old tools, left to right a 12" brass drift, Copper rawhide small mallet,Open ended BSF whit spanners for removing the fuel pipe connections Ring spanners , 9/16 x 1/2 AF and 1/2 x 7/16 AF ( the wee britool ringer is an all time favourite , had it for nearly 40 years now, this bike has a mix of BSF UNC and UNF , so more than one set of stuff is needed, two allen keys, the 3/16 AF fits the 1/4 UNC casing screws[Linked Image]
My Kamasa 1/2 " drive socket set, Imperial , AF and metric in one set, very useful. Used to remove head fastener but too clumsy to reach the centre head stud I use a 3/8 drive 9/16 socket for that.

[Linked Image]Rocker cover lifted, some fancy rockers in there , the inlets are non std, and have stellite pads where they touch the valve stems with adjusters at the push rods
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 06/24/14 7:55 pm

Getting the head off. First take out the exhaust rocker spindle a 15 mm ringer fits the nut and a long thin brass drift knocks out the spindle and is handy for keeping the spacers rockers and washers in order.[Linked Image][Linked Image].

Remove all head fasteners and the rocker line then aff with its heed.
[Linked Image]This head gasket was well sealed , no sign of blow by[Linked Image]Well maybe a little at the RHS rear stud , inner section only[Linked Image]Modifing the ring spanner for the base nuts, I already have one of these but it was twenty miles away, time to get filing[Linked Image]Spanner in action[Linked Image]Look at these babies, this was where I realised I had broken the first law of maintenance, if it ant broke dont fix it.These pistons are fresh , no blow by , why am I doing this, oh yes to save weight and keep the old girl running for longer, [Linked Image]Showing the knife edged skirt, cool running crown and unblued gudgeon pin, everything good.[Linked Image]Not scuffed at all[Linked Image]Warming up the piston prior to pushing out the gudgeaon pin, yes I did set the rags on fire, but only briefly[Linked Image]
BOOM stamped onto the crankcase centre piece, someone had a sense of humour[Linked Image]leaning up the base gasket[Linked Image]
Testing the new barrels for size[Linked Image]
Posted By: gavin eisler

Re: Big Bore alloy barrels for 750 OIF 1971 A65L - 07/11/14 5:55 pm

Managed to put some quality time into the build , the barrels were fitted, this was not quite plug and play, fair does to John, he did explain that the cylinder spigots which hang down at the barrel base were deliberately oversize ( to suit longer stroke motors with short skirted pistons), I had to relieve the outer edges of the barrel spigots by about 3 mm.

I used a 3/8" round file and cut a clearance zone at a chamfer going approx 10 mm up the barrel , this took a few trial fits as I wanted to remove the least possible amount. I enlarged the base flange stud holes for a bit more clearance, to 27/64". Also replaced the two base flange dowelled studs.

Here is terrible picture of the main brg cheek that was saying hello to the barrel spigots, my camera technique is somewhat lacking here , I will use less exposure in future. Ive tried to joey the image up , the con rod end cap bolt can be a frame of reference.[Linked Image]

Cleaned off the remaining joint compound with some petrol/ gas and dug out an old but fresh base gasket,
test fit showed that it needed trimming aroud two of the front studs

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The nuts were clatty, cleaning materials, aluminium foil, aluminum may also work, Belgom alloy and scotch brite, a job in the sun , nice, it took an hour ,


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Fitted the piston rings after opening up the second ring clearance a tad , why not, it may give better sealing, so a few strokes with a diamond file only took seconds..

Took the cam followers out of the old barrels and matched them to there original cams, , with a dod of anti scuffing paste to help them settle in. The pic is awful so Im not putting it in the thread,
cleaned up the cases a tad.
scotchbrite for the centre cases and a rag with polish for the outer

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Cut 3 pieces of foam pipe lagging at 3 .5 inches long. with 2 nuts fitted to the front centre stud pair it trapped one piece, 2 to the rear by the follower tunnels, gave great accessibility.

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The pistons were fitted to the barrels with circlips to the inside , this is so much easier to do one at a time. The pistons were set so the gudgeon pin/ wrist pin hole was just visible.

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The cam follower duct tape was a pain, I ended up jamming a rag down the follower tunnel to trap the followers. The pins slipped in a treat, Important , the squishability of the foam allows very fine adjustment of the barrel height relative to the con rod small end, this makes "fitting the pin " a piece of pish) and the with the barrels now resting with cloths against the rods the foam props were pulled and some well seal joint compound was smeared on the gasket.
. Nuts on , swish the pistons round a bit , to settle the barrels .Nip up .job done, will check the torque later.
This pic shows the releived area at the base of the spigot

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The head is next.

These pistons come up the bore a bit more than the old set, the 2mm gasket will offset thisa bit, I will measure the chamber volume with a burette once its built to get the comp ratio.
The pistons have had the valve pocket edges lightly radius, and they are lighter than the originals so I am leaving well alone.

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I spent a bit of time cleaning the stud holes and annealed the head gasket , scrounged up some 3 mm thick O rings to fit in the 2 mm head gasket for the oil drains,
Jon has supplied a correct bore gasket , with the holes tapped to give max gasket area, this is badly needed, the rear cylinder stud is awfy close to the bore.

IMPORTANT, the two rear centre head fasteners must be fitted to the head before lifting the head over the studs, its a squeeze, I may trim a thread or two off the rear studs just to give a bit more room, these big bore devimead pattern barrels are about 3 mm shorter than stock, stock would be really difficult, probably have to fit the studs to the barrel then double nut the studs to the barrels.

A test fit of the head
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The bike is now radiating newness, fading to oldness around the edges..
It was running well before the lay up, so I am doing minimum head work , the RHS exhaust valve is looking a bit hotter than the left and the coking is minimal.
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The trial fit with no gasket showed a light free join, and the fly cutter marks I put on the head with a light skim seem to be helping with the sealing.
Tragically , I dont have the good copper sticky gasket stuff any more, cant find it.
Its not available here in the UK.
Will use a light coat of the blue compound instead.
Need to find a suitable socket allen key to fit the inner head allen bolts ., and 3/8 torque wrench, will be reusing the old thick head washer.

If I can get some rhubarb I may make cylinder head surprise, or I may let the bike do its own ultra sonic clean.

I used to torque the old head to 28 lbf, this kit has larger threads , John reckons 30 lbf is safe.

Posted By: kommando

Re: alloy barrels for 750 OIF 1971 - 07/11/14 6:14 pm

Tragically , I dont have the good copper sticky gasket stuff any more, cant find it.

I got an aerosol can from Eriks couple of years ago, pricey though.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/11/14 6:19 pm

Eriks? let me google that. Ta

Looked, they only seem to have loctite products.
Posted By: Adam M.

Re: alloy barrels for 750 OIF 1971 - 07/12/14 1:26 pm

Gavin awesome thread, continue please smile.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/12/14 3:56 pm

Thanks Adam.
Back to the shop today to finesse the fit of the head studs,

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the two rear were trimmed by three threads and the two front by 1 thread. Spot the spider, rear stud pre trimming

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After trimming

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This tool helps with the torque up, I need to find the small torque wrench that fits into it.

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A man cant have too many tools, my all time favourite is the wee britool, second from the right.
Its a gem to use, the others are variously the curvy Snap on , Elora and Britool
[Linked Image] 2nd from the right.

If theres one new thing Ive learned today its how to use the Camera , its a Canon G10 , Ive found the manual focus function and the flash colour balance is now set to fluoro, hopefully the pics will improve.
Photo bucket is being weird.

It seems to be working again, heres some new parts laid out, new spokes top , Carb rubbers, gear pedal rubber, theres a new battery and a fresh rear arromax hoop out of shot.

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More of the same tools arranged a different way but also showing the 8 mm hex bit with 3/8 th drive ratchet and extensions. .

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Not too much goo squeezed out, excellent.
I took a flat file to the barrel pattern joins at the fin outers , dressed them all smooth to bonny them up.

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Hmm , the barrels make the rest of the bike look scruffy, these down tubes are more than a little battle -scarred.
A touch up may be in order. This frame still wears most of the original paint . A few years ago I was in Oban getting fish and chips for the family using the BEEsa for fast food and the original dealer from Edinburgh stopped me as I was heading off, he remembered the plate number as they were awarded certain numerical series, he was a treat to blether with, the chips got back a lot colder than normal that night.
He told me that they used to sell a load of Lightnings to US guys over here on the bases.

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That silicone rubber that I last used to stick in the headers still has a serious hold in the exhaust ports, its much more effective than the exhaust paste I tried before.

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I met this guy on the way back tonight , Jamie from Ballachullish, There had been a shinty match , he was very cheery, thats vodka and diluting orange, I think, he made me drink some. He works on shift with me.

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Posted By: kommando

Re: alloy barrels for 750 OIF 1971 - 07/12/14 7:50 pm

Eriks? let me google that. Ta

Looked, they only seem to have loctite products.

I went in for some bearings and it was on a display next to the counter and not a Loctite product, this was the Kilmarnock branch, it was dusty. I took the display can, it sprays out a coppercoat type substance.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/13/14 5:39 am

Ive found some rhubarb, the jelly pan and the spring compressor, Cylinder head surprise is on.
possibly the only advantage of a midsummer rebuild, Rhubarb is plentiful, weve already made cordial and Im using up the scabby leftovers.

Torquing thoughts, this web site will be handy
John suggests using a 1/2" combination spanner plus formula from the site above, Its another option, most folk can find the combi spanner fairly easily.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/13/14 12:34 pm

Ive had an interesting day.
I visited the polly tunnels to get some rhubarb leaves.

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Next door had a haul of chanterelles.

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I had some for lunch while the leaves were simmering then got the muslin bag, bucket and pan out.

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Its important to eat well when working on your head, so they tell me.

Cylinder head surprise, recipe, preparations

Cut a half dozen large rhubarb leaves , they have more Oxalic acid in them.

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Chop leaves and add to large pan of water .

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Boil for about an hour.

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Strain through a mesh bag.

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I tested out the cleaning powers on an old MZ brake plate, left it it for a few minutes.

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Some bits came out patchy, I think where there were oily fingerprints.

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Rubbed it a bit with a tooth brush from the tooth brush tree.

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Nothing quite like a motivational toothbrush from the Seas rich Harvest for getting right in about it.

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It definitely does something, confirming the old rural myth.

Degreasing the head first looks like a must do, better get some gunk.

These dips were only a few minutes each, with a bit of rubbing with the brush and cloth.

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The effect is quite satisfying, most of the surface bloom has vanished leaving pit marks, the denser areas around the cable entries look like they need hours rather than minutes.

I will put the Organic gluten free rhubarb toxic tea back into the big pan for cleaning the head.

Will try a one side dip for a half hour as a starting point.

Spent the rest of the afternoon looking for a substitute for the lost head stud washer and cleaned up some head working tools.
Dug out the spring compressor, found the bike key ( yay) didnt even know I d lost it.

Also found a burette, torque wrench , the wrench is nothing special, its only had light use by me its probably not dead on but its mid range is where I want it to be around 30 ftlbs,


TDC finder, some handy tapery thing , pointy things, allen keys and a good old screwdriver, the tape round the handle means its out of the old toolkit which is still in a safe place, so safe that it remains un found.

<a href="" target="_blank"><img src="" border="0" alt=" photo 2014-07-13174443_zpsb47b5e9b.jpg"/></a>

The tapery pointy thing are handy for the rocker shim mess around that comes soon.

For some reason the link is coming up rather than the image, but Im doing the same stuff.?
Found out why , too many pics in one post. Will do multiple posts in the future/

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/13/14 9:12 pm

Valve spring compressor, its a Syckes Pickavant, I made a bridge piece for the end from some heavy walled hydraulic pip, slotted on the milling machine then burst the corners off with a file.
Its made for the job.

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Showing cut out to access collets

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The inlet rocker with superflous washer and deead gasket left in place for protection

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Inlet rocker details, shimmed endfloat , stellite pads at valve end, polished. Originally the pads were much larger, I have ground quite a bit off, this was done ages ago.

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Warming the pillars to help the shaft out

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A terribly posed picture, the end caps get a clout with a socket to help free the collets, otherwise they stick.

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Casting marks and filed off flash.

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Trying to capture how lettle meat there is around the rear stud on the head, showing carbon in the chamber.

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This needs cleaning, a before shot

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Rear, pretty clean!
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other side
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The spider is leaving soon

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trying to use a packing case as a light box
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Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/13/14 9:15 pm

Head part two
Top end of valve spring compressor in place.

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Bottom end, the socket spacer is not needed, later valves came out without it, got the settings out of whack when I cleaned it up.
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A poor pic of the exhaust seat,

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The head held in a parrot vice with a thick towell to prevent damage, the tool in action.
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The parrot vice stripped bare
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It swivels round this centre pillar then locks when nipped up, a great idea for fiddly work.

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I may give this a D shape, the ports have been worked around the guides.
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A clearer shot of both exhaust seats, a bit of pitting but still nice broad seats, these will get a light rub before going back in.

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I am glad I pulled these valves now , that flake of carbon on the seat isnt going to help much.
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This is the only dodgy thread I have found, for some BSA reason, although the rest of a 71 motor has 1/4 UNC female threads, the rocker box is different, the two centre tappings ( the 4 outer holes are tapped 5/16 UNF) on this one are 26 tpi, 1/4 BSF. This one had a couple of broken threads at the top, here I am using a pair of sprung caliper legs with fine end to clear the bad threads out, theres still good purchase futher down, maybe a jog for a 1.4 UNC helicoil the next time.

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God the studs to an aesthetically pleasing length . Cabochon filing, what fun.

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Ive half a mind to alloy up the footrests as part of the weight loss thing, some measurements for an e mail to Barley corn.

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Showing the challenging , footrest , kickstart , gear lever interplay, thats bad road rash on the kick lever.

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Ive sussed the camera focus, set on manual at around 20 cm, its easiest to have strap pulled tight then sway back and forth till the image sharpens up.

The head is back home now getting degreased before the Oxalic dip.

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/13/14 9:33 pm

Back home cleaning the old mung off the head.

In the kitchen sink

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Its not that powerfull
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BSA service tool 71- 667, ornate japanese engraved brass cylinder head bowl. For holding an A65 head any way you want. An essential piece of equipment, note the serenity candle.

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Other way up, no bother.

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Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/15/14 7:31 am

After a a crude session at degreasing in the service bowl ( this donnggs in a very sonorous manner when handling the head, which amused me no end). I opted for some more aggressive chemical for the head chamber and bought some Gunk degreaser.

Scrubbed away at the carbon with 1500 grit paper ( slow but shiny) , looked out some tapering hardwood sticks to help reach the tricky bits.

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Chamber exhaust seat

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Showing exhaust seat pitting

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Inlet seat much cleaner

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Before Oxalic dip pics

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Immersed the head in the Oxalic solution and set a cooks timer to ten minutes, every time it went off I turned the head over to see what was going on.

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After ten minutes

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Used this to help

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Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/15/14 7:38 am

part 2

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After about 100 minutes, 50 per side.

Rubbing with AL kitchen foil really helped shift some of the more stubborn carbon, goo marks.

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The last shot is kind of telling, yup the head is cleaner, the rhubarb is working but it needs a bit more pizzaz. Took the dremel out and polished various areas with the small brass brushes. OOOh now its a bit tarts handbag, also took the rocker lid fasteners to the wire wheel.

Outside next day in the fierce midday sun. This is as far as the head clean up goes.

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Trying to show the central air passage, this had some sloppy casting flash masking clean air flow, I have dressed it up with the dremel dental burr.

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A better shot, the bright line is where the casting flash was.
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The head clean was a days work, this is some gods way of saying I should have tried harder at school, if I had " made it " I would have some lacky to do this for me. Head work is humbling.

Some thoughts on the Organic gluten free Toxic acid rhubarb Tea clean.

It smells OK, rhubarby , natch.

It starts pink and turns black.
I still have all my skin, rinsed fingers in cold water a few times to be sure.

The Al boiling pan prevents head damage.

I was probably hasty, I thingk and overnight soak may have had more effect.

It needed mechanical help.

The oxides seem to bloom into a yellow/ greenish layer which brushes off easily.

Would I do it again, yes.

Cheap, no grit, controllable. Backyard chemistry is fun.

Slow. Maybe too weird for some folk

Today, valve clean up and grinding.

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/15/14 9:16 am

Playing around in the sun before cleaning the valves.
To seal the inlets I wrap the stubs with a turn of self amalgamating tape. Some vaseline will help the rubbers slip over the grippy tape, the tape is stretched to twice its original length then wrapped, as it touches the long chain polymers which have stretched to breaking point reunite with the layer below to make a contiguous join, its amazing stuff and has worked well for me in the past for sealing this junction.

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Dig out an old inlet valve and tried some crude flow bench tests, result wet and inconclusive, needs more water.
Valve held at small opening.
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A spilt dowel with coarse grit is prepped for cleaning up the ports.

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Thats all for now. Valves to follow.

Posted By: Pre Unit

Re: alloy barrels for 750 OIF 1971 - 07/15/14 8:49 pm

If you put your finger over the end of the hose , and aim it down the center of the intake ,
youll get a fair approximation of the buisness .

Try various lifts , & valve & no valve .

This is best on hot days , or wear your raincoat .

Be carefull not to repeat this information , as its classified .
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/16/14 1:28 am

@ Pre unit, cheers, will give that a go at work where we have a better water supply.

While the epoxy cures in the head I took off the old rear hoop

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pulled the broken spoke, these are high flange Borranis, been on the bike since I got it in 1980

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New tyre 1/2 mounted

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This old ape came round and forced the tyre on with his bare hands ( not true, more like knees and feet), start to finish this took over an hour and amused the kids no end, I used a record no 5 G clamp to break the bead on the old tyre. While the rim was bare I put a drop of light oil on each exposed nipple with a view to tweaking the rim later, must find a spoke key first, the new spoke is so shiny.
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I reused the old tube, and completed the task without nipping it, woo hoo.

Also cleaned up the pipes, gunk , Al foil and belgom Alu , pics to follow, off to work.

Posted By: Adam M.

Re: alloy barrels for 750 OIF 1971 - 07/16/14 11:11 am

Hi Gavin, with cleaning a head soda blasting would be faster and still safe for the head.
Doesn't look as good as yours after cleaning though, still you can see the blasting effect.
About these valve seats - do they look like 3 angle job ?
They are quite wide and look like make with one seat cutter from factory.
Were your guides worn ?
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/16/14 6:56 pm

I am out in the sticks, no soda blasters around, years ago I had the head blasted in a shot cabinet, it came out very clean , but opened all the pores, which made it pick up dirt.

Doesn't look as good as yours after cleaning though, still you can see the blasting effect.
About these valve seats - do they look like 3 angle job ?
They are quite wide and look like make with one seat cutter from factory.
A friend fitted new iron exhaust guides about 15 years ago , he also recut the seats, did a nice job, broad exhaust for heat transfer, narrow inlets, the inlet guides were good, the valves were replaced with high quality stainless items, they will clean up soon.

Are the guides worn?

They are good, not much waggle at more than full lift, I am not changing them.I have thought about having SRM line the guides and recut the seats, but it was running very well before It was stored , so a light freshen up is the order of the day.That can come over the winter, I have limited time on the hydraulic bench at my friends shop and cant leave it hanging around.

The ports are still 3O mm as are the carbs, although some one has removed the inlet guide bosses and deepened the bowl around it.
I intend to give the inlet port a sideways D profile and have slathered epoxy on the floor to cure, there were some pretty coarse joins where the steel spigots ended and the port begins so if nothing else these will be tidied up. Ive half a mind to oval bore the carbs, raising the slide chamber roof to 32 mm but keeping the opening choke the same.

A bit of cleaning tonight,

Freshened the bars and top tube, removed some awful cable ties,
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Ah the rare mk V spitfire 750, the crossed flags of Ethiopia and Scotland must have meant something once upon a time.

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Some quality key fob rash

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Showing the shortened cranked gear lever, old footrest mount and long folding footrest stub needed to clear the motor and kickstart.
I tried rear sets and linkages, but this is more direct and with the 2 turns lighter index spring it is sweet.
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Back axle , showing outer spacer, speedo drive and inner spacer.

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Oily rag clean, then a bit of polish.
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New hoop, it had to be done, the old one was thin in the middle and a spoke had broken, now replaced.

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Size details

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This is a straight swap for the old tyre, I liked it a lot once I put the pressure up to modern style.

John, I will get the measurements you asked for later, I was in a rush tonight, I will have some time on Friday to get them.

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/19/14 3:38 am

The epoxy in the inlets has set. got busy with the split dowel sander and dremel.

I have filled the floor , and the groove where the steel stub meets the port.

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Cleaned up the valves on the wire wheel.

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These were expensive valves , supposedly using F1 materials.
The exhaust valves details on the stem at the collet groove are. "REC V254"

They are in excellent condition, barely worn at all. a slight shine at the thrust areas on the stem but no appreciable wear, I am happy to refit these.

Used this needle file to improve the porting, a teuchter 3 way valve cut, burst the inner corner of the inlet seat with a small chamfer and radiused the seat to cylinder head rim

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Showing inlet tract length about 4.5 inches from carb flange to valve centre, also showing modified torque wrench attachment, a kind welder attached a 3/8 drive socket to the 1/2 "ring spanner.

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A half decent shot of the inlet port showing valve seat
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MMMmmmm flange.
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Better check the carbs over, both had the pilot air screws one whole turn out,

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Wear ring on needles at pencil tip.

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Worn slide , Burlen are getting an order soon, will try the hard anodised lads.

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Son Robbie, with his new longboard, he fell off a cliff in May and broke his wrist , leg ( femur now pinned) and fractured 3 vertebrae, it will be next year before he is skateboarding, thats why this rebuild got derailed at the start, he is mending well.
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The valves are refitted and the head goes on soon.
Posted By: Allan Gill

Re: alloy barrels for 750 OIF 1971 - 07/19/14 9:59 am

There's not much epoxy in there Gavin, I'd put a minimum of 4mm upto 8mm deep ( before the seat ) to find any difference.

Those slides are really boogered, what are the carb bodies like? If the slide is worn that bad the bodies can't be much better.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/19/14 2:13 pm

Hi Allan. thanks for the tip, maybe later , Ive definetely improved some of the stub transitions.
New slides are on order, the bodies arent too bad, there the third set Ive put on.
Posted By: Adam M.

Re: alloy barrels for 750 OIF 1971 - 07/19/14 3:47 pm

Do you have any plans concerning frame painting ?
I powder coated mine and it really changed a look of the bike.
But knowing now you are out in the sticks smile I don't expect you to do anything so complicated.
New tire looks really nice on this alu rim.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/20/14 3:31 am

No immediate plans for frame painting, its only original once , haha.
In 1982 the swingarm and seat stays got a blow over ( brush up), the swing arm was rebushed at the time. , the front loop hasnt been touched since I got it.I would like it all gussied up but on the other hand this bike has never been pampered, just used it to burn fuel , oil and wear out tyres, pipes, carbs and stuff. Its a bit like an old slipper, well worn, but adapted to its owner.
I may put it on a diet, I have a good 1965 L back light that is a thing of beauty compared to the 71 boat anchor.

Just ordered a front matching hoop and rear sprocket ( SRM) , throttle cable kits ( Venhills), carb slides and rebuild kits ( Burlen). Head going back on soon.

Have tracked down some wee screws for the friction damper in the Tomasseli Daytona 2 C twist grip ( Bevel Heaven).

Fitting the carbs to the flange rubbers with alloy SHC screws M8 with nylocs ( probolt).

Finished NS today, will catch up on kip then crack on.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/21/14 3:01 am

Final jobs on the head.

Epoxied in the TS balance oioe stub, it was literally in by a thread

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Polished the chambers

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Dipped the carbs in the Rhubarb cleaner

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Mid way scrub stop

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Very pleased with the results, Brown varnush vanishes with a few rubs of the toothbrush.

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Oxudes take a little more persistence.
This stuff works a charm, it is a very gentle cleaner, there is a faint fusty smell when using it.
The 65 tail light housing is getting a dip as well.
I will keep this stuff and make a fresh batch for later.

Used this wee tripod that came with a cheap laser level

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, for the following pics

A thorough inspection of the carb ,

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original float bowl and float holding up well,

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viton tipped needle fitted in 1981 shows a wear ring ( getting changed)

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Float spindle polished with wear.

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Gasket in A1 condition.
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Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/22/14 5:35 am

Old needles pointing to float pivot zones, gasket must not interfere with float movement, this one is good.

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Showing float travel and sawn off clothes peg clip to keep the gasket down.

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Checking throttle spring length

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Its short, should be 3 inches.

The rhubarb dip has improved the look of the old slides.

Set up a multimeter on the 2000 mV scale to show electrolysis between cooking foil and rusty mudguard/fender with Oxalic dip as electrolyte, Max reading was 250mV.

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Found an original 71 rear mudguard in the shed with a 65 lamp housing.

Carburettor beetle
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Carbs rebuilt, showing 65 rear light after a dip, still awaiting the postal race, ordered stuff on Saturday, Venhills in first with Throttle cable kits arriving today Tuesday , still waiting for Burlen , SRM, ProBolt, and others,

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Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/22/14 7:56 pm

Spent some time making new throttle cables
Using an MTB brake noodle to give a cleaner entry

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Getting the lengths worked out.

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Venhills yo the rescue, excellent kit.
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New and old

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Selecting the right nipple from the kit

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These cutters do a good job

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Cut ends

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I like these dressed to a slight dome on the wheel, you must lose all spring to have a chance of keeping the carbs in synch
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Ground end, see the plastic liner, keep a pointy thing handy and poke it in the plastic hole when its hot after grinding
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One of the nipples had some extra material that stopped it spinning in the slide

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Filed it off

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Checked the fit

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Trial assembly

Washed the head down for a final clean of oil ways and stud holes.

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Will continue with more head work at the shop.

Tested the valve seal by pouring a little fuel into each port, all good.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/22/14 8:23 pm

Trial fit of head , light torque, add oil to chamber at TDC, measure volume
To the plug hole was 40 cc, about 45 to 1/2 way ip the plug threads

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New torque wrench set up, needs some sums

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Trial fit of cable , better than before, 110 degree noodles would be better still

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Shiny Toga mega
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Ticht aboot the taps
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I am pleased with the cables and the combustion chamber volume.

I did some sums, based on a swept volume of 362.7 cc bore 79mm stroke 74mm

CC vol Comp ratio
35 11.3 : 1
40 10.06 :1
45 9.06 : 1
50 8:1

My reading was around 45 , it was hard to judge exactly , I couldnt tilt the beast to put the plug at the top.
Still I reckon a manageable 9:1 ish is the recipe.

The head gasket will get its final anneal and the head will get torqued down once Ive worked out the fiddle factor for the torque wrench ( 300 mm handle to centre of drive) with the extension added ( 62 mm centre to centre).

The gives 24.8 for the 30 ftlb I want with this set up. 16.6 for 20. Will sneak up on it.
Posted By: robcurrie

Re: alloy barrels for 750 OIF 1971 - 07/23/14 12:32 am

Gavin, if you turn your adapter 90 degrees to the torque wrench, you won't need to work out any fiddle factor.

I am enjoying this build, and I don't even have to get my hands dirty!

Rob C
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/23/14 7:28 am

Thanks for the torque top Rob, I had heard this before, but I am sceptical, does this not mean that the torque is applied about a distance equal to the hypotenuse of a 90 triangle. The Hyp is longer than the T wrench so this ( I think ) would give a greater torque, or does the angle somehow compensate for that, convince me.
Posted By: robcurrie

Re: alloy barrels for 750 OIF 1971 - 07/23/14 7:49 am

You are quite correct, if you set the angle such that the centre of the ring spanner is at the same distance from a reference on the handle of the torque wrench as the square drive is, you will be more precise, but what's a footpound or two between friends?

(Some wrenches have a fixed square drive and the only option is 90 degree).

The important thing is to get the all the bolts the same.

Rob C
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/23/14 8:13 am

Ok Rob I will try this , the previous torque figures I used were 28 lbf all round, John is happy to use 30 lbf and has tested his fasteners in the ally barrel.
I do not wish to go past this. So I may try the angle method at the old 28 lbf figure and compare with the fiddle factor on a test rig.
Food for thought.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/23/14 8:02 pm

A little more time on the carbs , cables and inlet rubbers, of course one of the throttle cable nipples has pinged itself into oblivion, however there is a suitable spare in the kit that will shorten with a bit of filing.

I had bought light alloy bolts for the carb stubs but the heads were oversize compared to the originals and made the rubbers distort, the old ones go back on. I may turn down the alloy ones to fit but needs must.

These are grippy nyloc nuts , the bolt is tightened with the short head of an allen key till the nut just grips and the bolt will not turn, a light nip. Its a soft sandwich. This set up has been very reliable and I am sticking with it.

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fuel pipes, in surprisingly OK nick, a bit stained but not cracked or stiff, I think one of the taps had a bad seal to the tank.

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Its difficult to get those neat ends on with the banjo outlet angles, hence the wire , crude but effective. Theres no sign of fuel leaks at the wired ends, however the fancy crimps,.... juries out.

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Checking the HT leads plays nice with the cables

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Head gasket with tapped holes , I spent some time synchronising the fit of the bolts and now it needs to be annealed.
The alloy spacer makes up the shortfall in block height so the head steady fits.

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Before and after rhubarb cleaner advert

I want to fit something that will help take the weight off the carb stubs , they cost a lot and ruin your day when they split, so something that makes these last longer, and looking better,( they look dismal when they droop), . Maybe a leather strap round each bell mouth and up over the frame loop, big dog collars , mmmm. Any ideas? anyone?

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The carbs out on stubs cause issues, the air cleaner no longer lines up, hence the big plates that I made in 1981 with ally plate from the NCR . The air box outers were cut away when I got the bike and the carbs sat out on finned alloy blocks , no bell mouths , nothing.
Ive tried longer stacks , the sideways dalek type, but found the carb tuning changed a lot and never got it to run right ( I think a wee-er needle jet might have helped). The short bells are easy to live with. Ive dicked around with all sorts of fuel pipe runs and got back to this , which was what was fitted when I got it, there are some tight spots on the runs near the airbox but this is the least messed up looking. Moving the carbs any further back is not an option at he moment hence the thin insulator gasket between the flanges.

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My soldering iron, solder , blowtorch and flux. The iron head is loose , need to fix that first.

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Hoping to final assemble the head and stuff tomorrow.
Still waiting for carb parts, Burlens and SRM lost the post race. Venhills 1st, with Pro bolt and a random ebayer 2nd, SRM and Burlens tying for 3rd at the moment.

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/24/14 8:40 pm

Results just in, Srm 4th , Burlens still to finish.

Fuel pipes

It was hot. the cycle speedo hit 36.5 ( 103.5 F) in its blister pack, 26.5 up the glen.

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Stan of the dump, he is an old mate who helps out at the recycling bit pf the dump, I ditched the old battery and back tyre at the resyck and picked up a Singer sewing machine , hand crank stlyle with accessories box and book, plus 2 x 3/8 th drive ratchets , a 6 inch wood vise and so,e 1/4 drive sockets for eighteen quid.

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Checking the new fuel lines , the neat ferrules only fit 6 mm pipe, my fittings are 8 mm so it was into the local parts shop ( Franks in Oban for new line and clips),

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Annealed gasket, sealant O rings , and fasteners

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Head torquing tools, the 3/8 th drive Teng is nice to use ( from the dump today) , but the ball lock is poor.

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Degreasing the head mating surface with acetone before smearing some blue stuff on

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Any minute now.
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Fitting the studs to the gasket after applying sealant to the lower gasket face

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Bolted down in stages from 10 lbf, 15, 20 , 25 , 30.
A lot of dancing round the bike.

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Showing tilt of carb to clear fuel pipes and fuel cocks.
, runs fine like this .
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The rest of the shots havent come out properly on import.
Got the inlet rocker spindle in and called it a day.

These last bits of the build have been late evening sessions when its cooler. Scotland is melting at the moment.

Posted By: Mark Parker

Re: alloy barrels for 750 OIF 1971 - 07/25/14 9:06 am

Now I'm wondering what comp my 883 might have, if the chamber is 45cc it would be 10.7 50cc - 9.83 might check it and see. Cables look nice Gavin.
Posted By: old mule

Re: alloy barrels for 750 OIF 1971 - 07/25/14 2:32 pm

thank you for the shed update, nice to see a well used and well loved BSA, I say.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/25/14 4:33 pm

Thanks for the comments.

Yeh Mark , anything would have been better than the old throttle arrangement, I have great hopes for the noodles.

I learned what settings not to use on the camera, some pics are missing.

Back wheel refitted with new sprocket.

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Found this mouse damaged wire in the loom, the white , with yellow stripe, the single connector was not great either, Ive changed that. Thhe damage is only a small section, Ive isolated it and fitted heat shrink, the conductors and bullet crimp are sound.

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The other side of the connector , untouched!

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Got the head furniture in place.

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Sorry the rocker details are missing, camera probs earlier.
Head assembled, valves set to 6 thou inlet , 8 thou exhaust per John Hill.

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I wish I was about to reveal the all time best way to fit rocker spacers and spring "thackeray " washers. My best advise is stay calm, you will spend a lot of time knocking the spindle back and forth, I use brass drifts and the wee copper mallet, a couple of tips.

Fit the spindle slowly , belting it in is not on, fit the spring washers with the spring ends to the top so you can see whats going on. The last washer in the stack is the worst for me,
the rocker spindle is fully home when there are more than 4 threads showing past the nut
( no washer fitted, the Nut is a good fit for a 15 mm ring spanner , the other end is 12mm ( none of my BSF stuff fitted).

The inlet pushrods had to go in first they wouldnt play if an exhaust was in place.

Tool roll showing some handy stuff, the small LED spectacles light was very handy for push rod to follower location.

Left to right
Brass drift, 1/2 " and 3/16", assorted 3/8 th ratchets and copper mallet, spanners for BSF , 1/4 , 5/16 , 3/8th fasteners and fuel tap unions. 6 inch rule, control cable cutters, small screwdriver, 1/2" x 7/16 th AF ringer and spoke, 1/2" combe and allen key for 5/16 th fasteners, TDC gauge, feeler gauges , tweezers, the good britool short 1/2 x 7/16 ringer .Allen keys.

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Still some waiting going on , No sign of Burlens stuff yet.

Jobs to do.
Front tyre, Pipes ( Old ones are going back on , shouldnt be too hard), Carbs AWS , cables ( soldering throttles too length and make nipple fit, wiring repair), , Charge and fit battery, check spark, will the 25 year old HT leads , 11 year old Boyer and Primordial Lucas 6 volt coils still work?.

Clean decks

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Back to work for a set .


Posted By: Mark Parker

Re: alloy barrels for 750 OIF 1971 - 07/26/14 12:59 am

I just checked the compression ratio on the 883, tilted the motor so the left plug hole was up, used a syringe and measured about 40cc frown I did spend a lot of time filing the face of the cases to get them square to the crank and the valve to piston clearance was a bit small. Probably why it sounds so crisp. It had an issue with the R/H cyl. It was fine or seemed fine in summer but started to get smokey once winter hit, I'm guessing .002" clearance might not be enough when gassing it up when its coldish.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/26/14 1:55 am

Interesting stuff Mark.

Just checked my e mails from Burlen.

"Dear, gavin eisler

The status for you order # 200006336 has been updated to
Being processed.

You can check the status of your order by logging into your account.

Thank you for your recent order via our website. Unfortunately, some of the items on this order are not in stock as detailed below:

Part Number: RKC/559
Name: MK I Concentric 600/900 Series 4 Stroke Repair Kit
ETA: 6-7 weeks
Part Number: 928/06035HA
Name: Hard Anodised Forged Alloy Slide - Number 3.5 - Cutaway 900 Series
ETA: 6-7 weeks

Your order will be despatched once all items are available."

Thats not good service, lucky I kept the old stuff.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/26/14 2:19 am

Talking torquing.

I kind of rushed through the head fit.

Breaking it down a bit.

Thimgs you can do to help the head seal.

1 Flatten the head with a fly cutter, its hard to see in the pics but my head has grooves like a vinyl disc left from a skim in the milling machine with a fly cutter, this helps the gasket bite.
Only a handful of thous taken off , around 3.

2 Use the correct washers for the head fasteners, these spread the load better and help prevent distortion.

3 I retorqued my head the next day, first i marked the bolt and head with a sharpie, next I backed off each fastener an 1/8 of a turn, then retorqued and noted any change at the markings, all bar one returned to same, the one oddity went another 5 degrees or so.

4 Fit O rings at the oil drains, I fitted 3 mm thick O rings ,( 2mm gasket thickness), its not totally necessary but it should help.

5 A very light smear of gasket compound on each side of the gasket. ( Copper kote is good if you can get it.

5 Anneal the gasket, cherry red then a quick plunge helps shift the scale, do not worry about discolouration.

Valve settings. Correction.

My memory is bad, John recommends 4 thou inlet, 6 thou exhaust ( stock pushrods), will reset at retorque
Posted By: Allan Gill

Re: alloy barrels for 750 OIF 1971 - 07/26/14 7:37 am

Unless your running anything but a standard cam I wouldn't advise anything tighter than the stock setting, after trying tighter clearances on the 650, I found that all the tighter clearance did was improve the top end a little but kill off the bottom end power. Increasing the gap a couple of thou ( I found 10 inlet and exhaust to work best with a stock cam).

As for the o rings. I bought some NOS gaskets for the 650. They start off at 008" thicker than a newly made gasket - (048") I haven't yet measured once crushed. But most interestingly the oil drain hole drillings are much smaller than these repop ones and so far I haven't had any issues with the oil making past the gasket - not unlike the other gasket where I needed to use I rings.
Posted By: Mark Parker

Re: alloy barrels for 750 OIF 1971 - 07/26/14 8:40 am

Allan are you talking about tappet clearances with an alloy cyl? Because the cyl expands more with heat, opening them up. I'm using C/molly push rods that expand less and that combination requires zero clearance cold other wise the tappet digs holes in the lash caps. I would have thought an alloy cyl with std pushrods would also need some degree of less clearance.
Posted By: Allan Gill

Re: alloy barrels for 750 OIF 1971 - 07/26/14 10:56 am

Ah my bad. I wasn't taking into account for the expansion.

I'm interested at how the figures Gavin stated came about, was a height measurement taken from a cold and another from one at full operating temperature?
Posted By: JER.Hill

Re: alloy barrels for 750 OIF 1971 - 07/26/14 1:53 pm

Hi Allan

I originally experimented with 0.006" & 0.008" based on looking at other engines with alloy barrels. Then Mark P posted more information based on his long experience with his alloy barrel, which gave me the confidence to go down to 0.004" & 0.006" using standard push rods and its running good. Sorry nothing scientific or any fancy formulae to get you excited.
As Mark said using c/molly rods his running more or less zero clearance, which was the case with later racing Goldstar and Velocette engines. There's not actually a lot new going on, just a matter of updating to the use of modern materials and technology.


Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/26/14 4:25 pm

A look at the manual shows that the rodents had chewed the feed to the coils on the white yellow core from the RHS handle bar switch, will check the continuity/ resistance with a meter.

The heat has gone and the rain is back, Burlens 6-7 week delay is a scunner, may try Surrey Cycles, they have some nice carb stuff, brass slides and the like.
Posted By: kommando

Re: alloy barrels for 750 OIF 1971 - 07/27/14 4:21 am

I have used Surrey Cycles and always got good service, Hitchcocks is another option as they do the Amal range too.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/27/14 4:27 pm

Spoke to the nice man at Surrey Cycles, carb stuff goes in the post Monday.
I should get some time in the shop tomorrow, pipes and cables time.

Some filler details,
rear wheel , swingarm bearings, checked OK.
Cleaned out light rust from the rear drum, life in the old shoes yet.

I may have to splice some new wire in for the ignition feed.

The motor turns over well and has healthy but not massive compression. Will put a gauge on later. Hoping for about 130 psi.

Must order oil, I use Silkolene chatsworth 40, having seen how clean and un-scuffed the old pistons were Im sticking with it.

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/27/14 5:25 pm

Hi Allan
sorry for the late reply
you asked

"I'm interested at how the figures Gavin stated came about, was a height measurement taken from a cold and another from one at full operating temperature?"

I have , in the past messed about, getting the motor hot then checking, it was the old set up tho, I have tried closing them in from stock, it was so long ago I didnt take notes, but I ended up back at 8 and 10, ( more worried about burning a valve seat than anything else).
As I understand it the extra expansion of the block means slightly closer settings are safe to use.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/28/14 2:12 pm

Back having a look at the wires, checking resistances,

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the meter zero is o.9 ohms

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, its on the 0 -200 ohm scale, a close look at the stop switch block contacts

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Checking feed wire at the boyer end up to the stop switch
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Here we see dimensional instability in action, this fitted OK before I took it off

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Silicon in the ports
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Pipes are on
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Ians bead breaker in action on the front wheel

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New brake switch. ( They never last long)

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Nipped the tube, will refit tomorrow after repair
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Thats all for now

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/29/14 2:19 pm

Front wheel has a dodgy bearing, . N6204 , might have them at work.

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Assorted float bowl gaskets, no real turkeys, they all passed the float bowl gasket test. Steves Brit gasket item is very well made, sadly I dont have a pair so I am staying with the fresh Amal branded gaskets. They fitted well, not perfect but good enough.

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Carb parts came today, nice brass slides, new 106 NJs , matching needles , fresh viton tipped float needle valves.
The old MJs are going in, they dont wear so much as get varnished up.

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Slides are heavier built than the alloy ones. Old one on the left.Whew, the new slides are a good fit , none of the previous rattle, nicely made.

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LHS slide was a wee bit tight near the bottom,

Scrubbed out the carb with acetone to clean the bottom section.

Throttle twist grip assembly, some new bits, replacement stop screw and friction damper, these were missing before , its a Tomaseli Daytona -2C, got the spares from Bevel Heaven. This was on the bike when I got , but these bits were missing.This means the cables are non stock.

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Fitted new fuel pipes

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made up a throttle cable, cut to length and mushed the end up.
The BSA generates its own tools, the musher ( not shown , thats a centre punch which I used initially to fan the cable end in the nipple bowl.) is the old spoke from the rear wheel ground to a rounded end, Ive used it for various poking jobs, good tool . The last pic is after using the musher.

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Working, ahhh new cables, what a "must have".
Still to do the RHS

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Shortened this throttle stop screw. The throttle could only pull about 32 mm max, so I shortened it by about a half inch so it didnt stick out too much.

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Cable runs need adjusting, will take the cables round the front of the lamp for an easier bend.

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Shortened the carb mount bolts and ditched the flange gasket.
I need all the space I can get so the fuel balance pipe stops saying hello to the airbox. I have nipped up the flange bolts so that the allen screws can still turn with a bit of effort, this would be a good place for Alloy bolts or even plastic!

This bike wears Allen SHC screws , they make maintenance a lot easier, no chewed screws, everything has come apart with a positive grip. I know you can over-tighten them , but using the key with the short end to hand stops any over-torquing, it works for me.
A lot of the fasteners were sourced from various mega firms in Dundee , Ferrantis, Holo Krome and NCR ( The Cash) where I knew apprentices back in the day. The Stainless shock mount bolts were from Carolina Port B power station, ( Oil fired 2 x 120 MW AEI turbines ) I was apprenticed there.

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/30/14 4:32 am

Had a good look at the front wheel, changed both bearings,
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the central cavity had trapped a lot of water, partly ( I think ) because the sealed bearings ( which had only done a couple of thousand miles)allow vapour in , then it condenses/ gathers, also they were gubbed, the drive side had been dragging on the wheel spindle, a few thous of wear means its not a good fit any more.
New spindle time, or machine down and sleeve, for now its getting bearing fit .
The central cavity was coated in rusty mung.

It all spins well now on the new bearings but the spindle is a "must do soon".

The brake drum cleaned out ok, used 180 grit 3 M production paper, there is some ridging near the inner part of the drum, grit no doubt , the shoes are healthy and match the grooving, its going back as is., I might try and source some longer cam arms. The shoes were fresh in 2002. As were the bearings . hmmmm...

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If any one reading this has any experience of the longer brake cam lever arms can they let me know, good/ bad/ drawbacks ?.
I am concerned that the bars lever will run out of pull with longer cam arms.

The "comical " hub has a rep, I am sort of OK with it, twin discs are a whole lot better, but this one works surprisingly well if you squeeze it to the point twin discs would be locking up.
Before I fitted the heavy cable it was fair to poor, with the cable its , good to OK.

I will show brake cable shots later, the cable as found is in good condition, its very heavy , both inner and outer, with no switch., I have a new spare with a switch , for the brake light , to compare.

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The fork stanchions are straight and the rubber shrouds have protected the travelling seals area.
In an ideal world , I would prefer new stanchions just for the cosmetics, the upper chrome is fly blowm.
The lower slider need rebushed, the upper forward zone of the RHS slider is badly worn. Maybe an overwinter holiday at Maxton would be a good thing.
I would like the forks shortened, losing an inch or two of travel would be no great loss, it doesnt really need 5 ", and shorter would be stiffer .

Complete twist grip
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Complete throttle cables
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Hooked up choke cables
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For now its getting an oil change and polish.

Still have to mend the front tyre nip.
Will try the LBS for a 19" tube. Result.

Throttles feel sweet , got the routing sorted.
Tyre fitting, ( 3rd attempt) tomorrow. I may slaughter a warm blooded creature to appease the tube gods.
Cheers for now

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 08/01/14 7:42 pm

Sorted the front tyre, new tube fitted, I had managed to nip the old one four times, I think this was when it was removed with the old tyre, my friend who was helping is young and was unaware of tubes, any way its mounted.

Fitted the front wheel, and had a set back , the torque mount stud female thread in the brake plate is stripped , 3/8 " x 16 tpi, this will get a helicoil repair,but its Friday and bits wont be here till next week, oh well , never mind.

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Trial fitted the tank with all cables and pipes, no major conflicts, hurray, the reserve tap has lost its filter, and both taps are gummy from fuel, they are getting an over night dip in the rhubarb.
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Before rubbing with Al foil
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Must find some suitable washers to reseal the taps.

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These old school taper 1/4 turn pet cock/ fuel taps are a big step up from the old push pull cork plunger types. Because of the carb stubs the old push pulls have conflicts .
I found these in a drawer full of carb stuff a bout 12 years ago, Im keeping them , they should clean up OK, need to solder in a new filter as well.

Drained 1.4 litres ( about 3 pints ) from the sump.

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Put a fresh battery in, lights all work, foot brake switch works, horn doesnt work ( the vibration will fix this, its done that before.) Sparks were a bit meagre.

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Remade all coil connections removing the Boyer crimps that John Healy doesnt like, they were a bit loose at the terminals. The new crimps are made with better pliers.

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So the 11 year old Boyer , 30 year old HT leads and 40 + year old coils work, quell surprise.

Kicking it over with the sump drained and plugs in it feels very crisp.

Getting there ,

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Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 08/02/14 10:12 am

Fuel valves, pet cocks, gas taps, who knows
after a dip, with donor filter to be soldered in.

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The old ignition switch with keys , showing drilled out rivets replaced with screws and nuts.

One of the old contacts was so far gone I had to replace it with a brass screw
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Its hard to beleive all those mighty lucas electrons are meant to pass through this, Im posting it as an achilles heel look out for other people trying to fix their old mounts.

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This is not the switch currently fitted , I looked it out when searching for the key.
Posted By: Adam M.

Re: alloy barrels for 750 OIF 1971 - 08/02/14 3:40 pm

Hi Gavin,
great story like always, congrats smile.
To write about bike reno and make it interesting needs some talent, I'm sure.
I too swapped my former Lucas connectors with metal crimps + plastic covers sold separately giving me better crimping ability. Only problem is the quality of the metal connectors, sometimes they are so thin they last couple years on my BSA.

Going back to petcocks, what is the method of sealing yours ?
I still fight my push pull ones with some success lately.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 08/02/14 5:44 pm

Hi Adam,
Thanks for the kind remarks, I am in the middle of refurbing my fuel taps right now , I have one close by which needs a filter refit. ,
I have 1/4 turn taper cocks fitted, they got an overnight dip in the Oxalic acid, then stripped down,

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the moving taper was lapped in with brasso and the spring was cleaned in phosphoric acid, rust eater,

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after cleaning with polish I wiped it clean and lubed the taper with soap before re assembly .

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\it went back together well and feels very nice to use now.

I dipped the filter in a mix of malt vinegar a sodium percarbonate, it frothed up well.

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After a twenty minute dip in the can

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Showing the 4000 year old flint scraper that came with the brass service bowl.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 08/05/14 1:47 am

Some delays caused by life getting in the way,

While I wait for the helicoil kit to repair the front brake plate , I thought I would strip it and re lube.
The red pointer is on the stripped hole

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Rivetted shoes

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Operating arm as found, some grease some water

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Showing water damge to bearing surface before cleaning

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After rubbing with Al foil

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Cleaned parts, the brake plate got a swift rub down and blow over with matt black heat paint.

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T^he fuel filter is repaired , will head over to the bike on Thursday, hopefully.
Im runninhg out of jobs to do.

Fork oil change , but I may get it going first.

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 08/06/14 3:36 pm

Back in the underground layer
with helicoil kit

9.9 mm just took out dust and a few shavings

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Tapped for helicoil

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Coil in
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A ten minute job if you have the gear, helicoils are great!

Rebuilt using a dab of grease here and there
I have been using this grease tin since 1974, good value, its nearly empty though.

The hub lever system is well engineered , the micram adjusters are set for max clearance on re assembly, these will be set when the wheel is installed.The piston cam followers and lever spindles are neatly sealed with O rings, a nice touch to keep the brake clean, the micram adjusters just get a suggestion of grease to prevent corrosion more than anything.The shoes are about a quarter worn , they worked well before and are going back in.
The shoes went back on without drawing blood, assembled all bar one spring, then fitted on, fitted the 2nd spring with the shoes lifted at the sides, popped on easy.

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A ceilidh with AA in the control room, he is a fellow beesa ( 68 Thunderbolt, with original pipes) owner and all-round good guy.

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Wheel on tomorrow.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 08/07/14 1:46 pm

It runs, fuelled up with 98 ron , cured a couple of minor leaks, loose float bowm and banjo RHS.

Kicked over with choke and tickling, running steady after 3 kicks. Took it for a run, needles were too lean, loads of spitting when accelerating.
Next run, raised one notch , better but running on LHS only, RHS needle was out of its clip. next run better but lumpy. synched carbs, next run very nice.
The motor is crisper , higher comp than before, pulls very well from 3,000 ( on the smiths instrument which still works ) , had it up to 5 K briefly , pulling great.
I am cock - a - hoop.

Only leak at the pipes was a small hole on the RHS header , plugged up with anwee screw.
Out in the sun.

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My son has a go pro, once its leagal and dialled in, ( tickover is still to be fully sorted)
I will go for sound and movement.
Its been a blast .

Posted By: Ger B

Re: alloy barrels for 750 OIF 1971 - 08/07/14 1:48 pm

Well done! :bigt

Does the brake work as you expected?
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 08/08/14 3:17 am

Thanks Ger

The brake woyks as expected. It takes a good squeeze , unlike a modern twin disc.

I had forgotten how sweet the handling is, I like the big wheels compared to the wee doughnuts
fitted to modern bikes.

The weather is back to rain here and I am on night shifts. Will book its MOT for next week.
Posted By: Ger B

Re: alloy barrels for 750 OIF 1971 - 08/08/14 5:54 am

It takes a good squeeze, unlike a modern twin disc.

I'm always surprised when I get off the Hinkley Trophy onto the A65T and vice versa.

Posted By: Adam M.

Re: alloy barrels for 750 OIF 1971 - 08/08/14 9:51 am

Looks great, Gavin.
I had to make very quick decarbonisation of my A65 head as well.
Putting it back together tomorrow.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 08/08/14 10:41 am

Its never over over or easy.
Ordered some no.78 drills and 2 BA taps for cleaning the pilot jets, I am not convinced they are metering properly.
Still to do.
Fix the horn, fit cycle speedo for MOT, Have a decent run, re-torque head , take compression pressure readings. Change oil all round. Later, send forks to Maxton.

Its been a fun rebuild.

Many thanks to the following in no particular order.

John Hill,alloy barrel creator, he has been following this thread closely and offering advice and information when needed.

Ian Shellcock, for the use of workshop space and copious cups of tea.

Tony Salmon , the friendly welder at work.

My family, for putting up with me in Beesa rebuild mode ( must stay focussed).

General impressions, after a couple of test rides.

The 21 / 47 gearing feels about right, the motor is happy at 4k on a very low throttle opeming.
The carb mixture settings need reviewed. The higher comp motor may need more main jet, it certainly needed the needles raising , although the needles were probably on the top notch to compensate for wear on the old carbs. The pilot mixture seems happier with the adjuster screws at less than one turn out , hence the n0. 78 drill order.
The controls are sweet, any extra noise from the alloy barrel is compensated for by the tighter clearances for pistons and valves, its certainly no noisier.
The bathroom tile silicon left overs used for the zorst pipes works very well, no leaks.

In seven years the bike will be 50 years old, it may get a celebratory paint job.

Posted By: Rickman

Re: alloy barrels for 750 OIF 1971 - 08/08/14 11:46 am

Just some thoughts;

Years ago, when the small cc mx'ers started going to the really large cooling fins, trying to dissipate the large amount of heat the high horse power engines were putting out, before serious efforts at water cooling came about, several of the manufacturers started putting small .. rubber? discs between the fins, to dampen the singing fins' vibrations.

I think Yam and Suzi even at one short point, used a strip of rubber blocks along the outside of the fins???

You might try to find some high density rubber blocks or discs to place between your cylinder fins? Maybe bits from some old tire? Especially an off road heavy lug tire...

I think they found that if the rubber fits snugly enough, you don't need to put one between each fin, just alternate fins? So that each fin touches the rubber?

......... Maybe [ never tried this myself ], if you find long enough blocks, you might try to angle the blocks to try, TRY!, to 'duct' air further into the ... throat? depth of the fins, to get better cooling???
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 08/08/14 12:42 pm

@Rickman, I have some MZ 250 barrel rubbers, they may get a try.
Posted By: Rickman

Re: alloy barrels for 750 OIF 1971 - 08/11/14 8:47 am

Heh, Gavin,
Had a brain joggle this weekend!

I don't know about your area, but along the freeway, there is way too often a strip/chunk of shreadded re-cap tire from some underinflated semi-truck tire.

There is your useable, cut-to-size as often as you need, heavy, thick, compounded rubber!
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 08/12/14 9:13 am

Theres no free way for about 100 miles where I stay, but we still get truck blow outs so there
are plenty of roadside donors, nice idea.

While Ive been back at work the postman has done his thing and delivered the following from Chronos tools

The "Model Engineers Yearbook "

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is a must have for useful info.
Eg. co efficient of expansion for alloy =0.0255 /degC , irom,=0.0102 perdegC dural =0.0226 . hence alloy expands nearly twice as much as iron, so push rod tappet settings may be halved. My old copy went missing at work.
As a reference its more comprehensive than Zeus books. Its not often I buy the same book twice, but for me this is a must have.

The wee drills are for clearing the carb pilot jets , no78 s or 16 thou.

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They are the tiny packet ( 10 of ) between the taps.
The carbs are getting a revisit, float levels will be set to 60 though below lip and 2BA taps are present to create cleaning plug holes opposite the pilot jets as per the Bushman site article.

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 08/19/14 4:57 pm

Oh frabjous day, calloo callay.

Finished a wearing set of shifts, , Ive been through the carbs,
created the pilot jet drill tool . Checked the float level per J Healy, and the Bushman site, they were both fine , about 60 thou below the bowl face when pushing down the float tangs, no fannying needed.
Theres the no. 78 drill on the tweezers

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Theres the plastic tube which will allow me to handle the drill

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The drill glued and squeezed into place

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I turned my back on the lightning and this thing nicked its bench space, its got 2 too many cylinders.

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RHS pressure readings, carbs dismounted, 140 psi after about a dozen kicks.

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LH cylinder readings after ten kicks ( foot getting sore) 120 psi

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Will take more readings after the bores have settled in.

No more pics but plenty to tell.
Today had mixed results.

With the pilot jets cleaned out with the no 78 drill, things steadied up at the idle end , and the pilot air screws settled down at more like 1 and 3/4 turns out.
The first run was a bit of a disappointment, attempts to stabilise each cylinder idle settings showed they were well out of whack.
Off with the tank, pulled the slides, the LHS had the needle dislodged, my bad for not wearing glasses when reassembling.
Put it right . Fixed the horn, it was just needing some TLC , it came back to life after cleaning the terminals and checking volts were going to the correct places.

Brimmed the tank, sadly there is a fuel leak from a pinhole above the LH fuel cock at the top of the tunnel. Fixable but a pain in the backside with the MOT coming up.

Next run with a bare gallon on board, carbs synched at WFO and full shut, pilot screws at 1 AND 3/4 TURNS OUT.
Result, bike runs properly, a sedate run out to a private spot, , slight tweaks to the carbs, a 1/2 turn in on each pilot screw and a 1/2 turn lower on each throttle stop, now we are talking, no fluffs, no spitting, clean pickup, steady idle.

Took it to 5K in 1st , 2nd and 3rd. What a great sound, a proverbial tearing of calico.

Ive found some pairs of larger main jets, 240s and 250s. Will try them next.

New rubber feels good.

Its a shame about the tank, there is a good local welder in Oban , Figgsie, he will be getting a visit soon.

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 08/20/14 1:11 pm

Busy today, fitted the cycle speedo, discovered a broken seat hinge, new ones are in the post.
Patched the pinhole leak in the fuel tank using 2 sticks of juicy fruit chewing gum, put a scant amount of fuel in the tank and bungeed a plastic spare can on the back of the seat , the bungee helped keep the seat in position.

The ride in was pleasant, 69F on the cycle speedo, dry and a west wind. I took the back road from Connel to Oban , lots of low revs low gears, running well, even dodge a "close one " on the single track when a 4 x 4 appeared round a blind bend with no where to go, the self narrowing circuits kicked in and the skinny twin found a space beside the wing and the verge.
A fun ride apart from that.

At the testing station at Stoddarts in Oban, parked beside one of those cheap foreign imports, the "Bro " was in to have his clutch adjusted because he couldnt hit neutral when the bike was not moving.

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It passed, taxed for a year, note Juicy fruit petrol tank repair kit.
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The ride home to the normal shed was good,
some notes from the speedo, the minimum no stall speed in 1st is about 12 mph, the bike has my favourite blend of gears, the high 1st and 2nd, std 3rd and top.
In town 1st and 2nd are enough. With 21/ 47 sprockets the speedo reads 60 mph at about 3,300 rpm and 70 at a shade under 4,000 rpm.
The gearbox and clutch are behaving, able to select neutral at rest when its warm with no clunk!
It was already sorted from the prior rebuild when the crank was ground in 2001.

Of course now the bike is legal, the weather is breaking and its persistently falling at the moment.
The pic with riding gear shows my new lid. A nitro carbon fibre thing, its so light, you are barely aware of the load on your neck.
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Next instalment, maybe get the go pro going before summer blends into Autumn.
Fixing the seat hinge, Fuel tank repairs, mileage and the eternal battle against entropy. Ive found some 1/4" dural plates to reposition the footrests , an inch or two further back would be good, have some 1" OD alloy rod stashed to make spacers, will mount the plates to the footrest webs where the current rests are. I need to order a new bellmouth for the RHS carb, it broke when I fumbled the carb. Im quite tempted to fit the repop one piece sidepanels that replace the existing air box, this would allow regular pancake filters to be fitted. This will need a bit more thought.
Maybe while the tank is off getting fixed.


Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 08/21/14 8:11 am

Some things have gone unsaid because there have been no issues with them.
The most important being the actual topic of this thread.
The alloy barrel conversion.

As it sits after about 40 miles running , the first 20 or so with very poor carb set up, I am very impressed by the new barrels set up.

Some detail notes, the original Devimead iron 750 barrels used stepped centre bolts with a reduced thread where they screw into the barrels, this is a major difference with my set of alloy barrels, there is no step down so the threads are larger where the five central bolts screw in. Although this loses some valuable meat between the barrel bores and the rear fasteners the cylinder head gasket is tapped at these locations to maximise sealing area.
I must admit I was a little concerned about this.
However John was sure that as long as the head gasket was freshly annealed this should not be a problem.
Because my barrels where the first 750 set, my head bolt set is unique, John will be making subsequent bog bores with the stepped studs like the original devimead barrels.

He was correct, although I have not yet done the 100 mile re-torque, as fitted at the rebuild with fresh annealing , blue sealer and staged torquing to 30 lb f, there are no signs of leakage at all around the head joint.
The barrel joint settled a bit after the first couple of cycles and has been nipped up, this is normal as the barrel base gasket beds down.

The whole motor seems oil tight, a few spots have been spat out the breather due to a wee bit of wet sumping but you get that with them, sir.
In the past I have always used SRM gaskets with a thin smear of whatever compound is de-rigeur on one side and grease on the other. All faces are dressed smooth with all threaded holes chamfered at entry. I have variously used Silicone RTV, Hylomar and "Wellseal" for gasket smearing, they all have there merits. I hear a lot of posters running down RTV compounds, I remember when it was first introduced ( orange Silicone RTV) and what a boon it was compared to "Red hermetite" , ugghhh, that stuff gives me nightmares. Incidentally the whole Safety Cosh paranoia thing at work means we no longer use Hylomar in the power station, the black squad guys used to love it , nothing else comes close for some jobs. My motor has the drive side main oil seal with the spring and lip to the primary side and the stock timed breather system, I seldom go beyond 5K on the road, a race bike would need bigger holes.

My primary drive is stock apart from an Alloy pressure plate, and surflex plates, lubed by TQF.
The ball ramp clutch release is tricky to set up, once you know the trick its way better than the hinged wand fitted to earlier A65s.
Gearbox is stock, CR 1st and 2nd, polished camplate , two turns trimmed from cam plate indexing plunger spring. Its like a Suzuki box ( well almost), thats the highest compliment I can pay.

The cam is the stock "Spitfire " profile and the followers are also stock but lightened , I think SRM re-faced them 11 years ago, . The primary side inlet lobe was a little worn compared to the others but things are only perfect when they are new, and this bike was new in 1971.

The LHS has compression at 120 psi , the RHS at 140 psi, the next time I take these readings I will do the LHS first. My instep is sore from kicking this over and my foot / commitment was less for the LHS when I took the readings . I hope thats all it was.

When the rocker lid comes off for the re-torque I will revise the tappet settings down to 4 inlet 6 exhaust, running at 6 and 8 at present its certainly no more clattery than a stock A65, without a stock beside me for comparison this is a little subjective. I may visit a fellow Stock OIF owner in Killin for a sonic evaluation.

11 years of riding a modern bike with twin discs and electric foot have softened me up a tad. But I am having fun playing tunes on the old girl, from purr to blair with a satisfying hooharrggh on change down all at the twist of a wrist. How amusing.
The middrange torque and lack of gearchanging compared with my revvy 650 raptor is satisfying. The cramped foot rest to gear lever set up is not. This was OK 20 years ago, now its annoying, we get less tolerant as we get older . Praying for the sky to clear so I can get some miles in and take some posed scenic shots of the 750 Mk III Spit in its natural habitat.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 08/21/14 5:05 pm

It dried up long enough for a run into town,empty roads at the magic hour , 19:00 - 20:00 cruising in at 3,000 rpm and a whiff of throttle I still had the odd spit back until it was warmed through, in town it behaved well.
Enjoyed the positive handling round the shell gripped sweepers at Achnacloich. Practised hauling on the front anchor a couple of tomes to get the feel back, it needs commitment but works well, a bit too much fork dip for my tastes , but thats partly my extra lard to blame. The rear brake is very handy in town.

Picked up some Ale for the weekend, and came back through Glen Lonan in 2nd gear most of the 9 miles.

Its a very narrow B road with passing places , gravel , sheep, Highland cattle and the odd deer on a good night.
Towards the end of the glen the wee road is a snaking ribbon of ancient chicanes, the road being the old route for taking the kings of Scotland overland to Oban on their last trip to the burial grounds on Iona, no modern planner would make a route this wiggly.
The blare and hooo harrr from the beesa do a good job scaring the sheep off the road, had the rear step out a coup[le of times on gravel and the cattle grids, all good clean fun. Back into the village then out to wards Crunachy on the A82 , Its a real two lane road, empty at dusk. Out and back with a rising crescendo though the gears then back to the village, I coasted through the back way in to the village in neutral with the bike ticking over and parked at my friend Trevor's caravan , he is a tinky from Essex , within a minute there were three folk round wondering what the noise was, in a good way, thankfully.

A rare night out, the motor is loosening up well.
It disnae get much better.
Posted By: Pete Suchawreck

Re: alloy barrels for 750 OIF 1971 - 08/21/14 6:48 pm

'Tis a fine thing indeed, bedding in an old girl... Nice writeup. Been doing the same with my Bonny, I'm a little further down the road with it. Still adjusting from '06 brakes and shifting to '72. Such fun flinging the bike around out in the country. I have stiffer front springs in the mix for the same reason/problem.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 08/21/14 9:32 pm

Thanks Pete, its a fine time between worn out and run in ,entropy just claimed the back light bulb,
LEDs maybe the answer. Trev noticed the no show on the way home, cant wait to get the re-torque and fluids change out of the way.
I would like the front end to be an inch lower with stiffer springs, are all OIF stanchions the same?
I know the Hurricanes had longer legs but did anything get shorter, the 70s were a weird time for forks.?
The carbs havent been truly balanced yet, I have a balance gauge with a loop of plastic and a ball bearing to show imbalance it works well on the Cagiva, I will set them up with this soon, at the moment they are in synch but only to the visual aids of WFO, i.e both exactly wide open at the same time. Running pretty well non the less.
Getting a go at the main jet settings will be tricky. My favorite hill for this is 80 miles away.

On a totally different tack.

No 78 drills,

what a boon, what a Marketing opportunity , every Amal carb kit should have one.
For years Ive dicked around with bits of brass wire and solvents,
This site is great for info and the


should get a banner of its own. Hats off to John Healy and others who put this out there.

If you own an Amal Mk 1 Concentric carb on an A65 you need one of these.
Probably the smallest tool you will ever use but one of the most effective.

Cold north easterlies and dry till lunchtime tomorrow, , should get some miles in.

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 08/24/14 6:21 am

In Oban posing with the tourists

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The start of the Glen Road

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A tricky corner
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A gravel bed on the bend
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The signs have seem better days
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Ben Cruachan
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Some west highland ladies, outstanding in their field

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Crazy corners a small sample
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Magnetic sump plug , not too many iron filings

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The right amount in the sump
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John showed up mid oil change.
His spitfire
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Posing down the pier , Loch Etive , with Bon Awe quarry on the other side
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We went for a run together, the roads were heaving with tourists, after 50 miles I turned round at the burger van at Glen Ogle after a welcome cuppa and venison burger.

Ive lost an inspection cover,from the primary side, to stop oil spraying out I replaced it with the TS clutch cable access cover.

The 750 has more midrange torque, John having to work his bike harder to keep up with the 750 never over 5 K. There is a definite cough/ spit as I come off the idle circuits, a number 3 cutaway will be tried.
Cruising around 60 at 3,100 rpm this is just as the throttle is in this zone so its very obvious.
This weekend has been a bank holiday, the roads were busy this afternoon as we picked Ceps and Chanterelles in the forest a lot of fast sounding bikes went by. Sadly one of them was being shovelled up at a road block near connel about 15:30, I hope the guy survived, but it didnt look good.
I will have a nipinty Oban later during the magic hour while the hoi palloi are suffering food sleep and vid/soap mind control.

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 08/27/14 1:16 pm

Fungal harvest, great Ceps and chanterelles , while we were picking these the boy racers were out, the bad prang near Connel wasnae too bad, the victim got off with a broken pelvis, no other vehicles involved, ran out of road on a tricky tightening left hander.
[Linked Image]

As a BSA twin carb owner , it seem to be my duty to chase my tail round for carb settings.

Now the motor has three hundred or so miles on the bores , the handfulls of throttle are getting larger. It seems to be running out of pech beyond 5K , so in the spirit of get the main jet right before other settings I have fitted 240 MJs , 20 up from the previous 220s.

[Linked Image]

Because of the cough / spit at 1/4 throttle , I had richened the pilot mixture to 1/2 a turn from full in, this was reset to 1 whole turn out at the same time as the mains were upped.

Quite a bit of tank debris in the float bowl drain cup.

[Linked Image]

Found a willing welder in town, this will fix the tank, I will drop it off next week.

Gerry, the willing welder also recommended that I visit Allie at the wee bike shop, it turns out he is into old brits as well , heres the BSA with its prettier 1/2 cousin, a handsome T140 with a single carb and old style side covers and headlamp brackets. Its got the extended brake levers on the front, Allie gives it the thumbs up.

[Linked Image]
A handy guy to know. He will be getting the next order for odds and ends, .

The motor is picking up better with the larger MJs, less of the baaadddidbaaa,, spit, when on a steady throttle around 1/4 -1/2 open. No more missing.
The roads were too busy for a full throttle tests , but overall it felt more like it.
Presumably the higher compression ratio needs more on the MJ, I reckon the old CR was a lowly 7.5:1 ( 120 psi) , the new barrels and pistons are more like 9.5:1 , my foot hurts in a way it never used too. The weather has been good today , very pleasant, the tail end of summer. Off to Tiree soon so getting some miles in while I can.
Posted By: Adam M.

Re: alloy barrels for 750 OIF 1971 - 08/27/14 11:16 pm

Hi Gavin,
really enjoy the story and your English, in what part of England do you live ?
Just did 200 km trip last Sunday with a friend on the Thunderbolt and found out how much better
21 t. countershaft sprocket is compared to my 20 t. for cruising smile.
Less vibes and revs makes everything much more pleasurable.
My bike works very nice, but after 2h of riding with speeds between 60 - 70 mph vibration is wearing
thin and I have to slow down.
I had this problem before of not being able to rev much higher than 5K, but it was with big port's head and my low comp engine, with the same compression and a small port's head the engine revs like a turbine. I expected 750 engine + big port head to work like mine 650 with small ports, was I mistaken ?
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 08/28/14 2:37 am

Hi Adam, the clue is under my Avatar to the left of my thread posts.
I will let you off gently , I see you live in Mississauga , Ontario, would it offend you if I asked what part of the USA that is in.?
My language is lightly doctored lowland Scots ( lallans is the dialect) mixed with a few Gaelic terms, i.e. Loch, Glen. My dodgy syntax comes from having a Polish father.

The UK is a collection of 3 countries, Scotland , Wales and England, ( Ive left Ireland out, because its semi independent, southern Ireland ( Eire) is not part of the UK, Northern Ireland still is part of the "union") on September the 22nd Scotland will vote on whether it wants to separate from the UK. There is a good chance that it will. Interesting times.

I am glad to hear your motor responds well to the smaller valves/ports, for a single carb T bolt the later big valve heads are probably overkill. Running 21/ 47 gearing does give a more relaxed ride at 60 mph.

I am curious about the jetting changes my rebuilt motor has needed, I dont think its just the raised compression, when I first got the bike it had bumpier pistons and no base gasket, and it ran fine on 220s.
I think the need for more fuel is caused by better air flow and the Alloy barrels running cooler.
Ultimately I intend to put the bike on a dyno with an air fuel ratio measurement and do some measurements . There is a dyno place about 100 miles away that I have used before when I was fettling the Raptor.

Posted By: Adam M.

Re: alloy barrels for 750 OIF 1971 - 08/28/14 2:30 pm

Yes, silly me - never checked your avatar.
We used to have an older Scottish couple as neighbors for close to 20 years - we could never be sure we understood them 100% smile.
But they were great people and great neighbors, we really miss them now.
I know everything about what G. B. consist of and heard about your referendum. Read quite a lot about English / Scottish history - very interesting to compare it with polish history.
I believe you know I'm polish living in ON, Canada ?

Anyway coming back to motorcycles I bought a triple ( 73 T150V )
and intend to rebuild it during the winter.
Try to write about it, like you did with lots of pictures, but I'm quite sure I couldn't make it as entertaining as yours.
I believe only dyno could give you definitive answers about setting your carbs properly.
Posted By: Allan Gill

Re: alloy barrels for 750 OIF 1971 - 08/28/14 5:31 pm

A dyno will get you close, but things like altitude, head winds etc will effect the jetting which a dyno won't take into consideration ( unless your running at the same altitude as the dyno)

Gavin, is it possible that wear in the throttle bodies are acountung for the need to richen the mixture? Or has ignition timing changed at all ( retarded)
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 08/28/14 6:04 pm

Hi Allan,
today I raised the needles to the last / lowest notch just to see what happened next.
Within a mile I realised I have been barking up the wrong tree, the off idle 1/8 th to 1/4 throttle opening became much worse with very severe spitting and blubbering.
So its back to the drawing board. Tomorrow I will put the needles back to the top notch and see what happens. I think my initial tests were possibly confused by the needles not being seated correctly when fitting the throttle springs.
I visited Ali ( West coat motorcycles in Oban) today and ordered a pair of 230 Main Jets, no. 3 slides, and new float bowls.
My old bowls are a little warped and I want to rule out air leaks at the gasket.
In the battle against entropy I need to redouble my efforts, the kick start spring just broke!
The ignition timing has not been touched for about 12 years , its the Boyer red box and it worked very well before. I did remake a few connections to be on the safe side, will check at the pickups to make sure nothing is amiss. Also will put on the strobe to be sure.
Over 1/2 open the carbs are metering well and pick up very cleanly.
I should have bought new carbs, the wear isnt so bad on the old bodies, but for all the bother , new ones would have been a lot less hassle.
The only original parts left of the old carbs will be the lids, float spindles and floats once the float bowls are changed. ho ho. 5 new slides and 2 new bodies later.

Adam, I was unaware that you are/were Polish, my old man came to the UK in 1939/40. Married my mother ( a Scots lass) in 1945 I think. His old home village is now part of the Ukraine thank to Stalin's border reshuffle. He was from Buchasz ( Sp?) near Lvov.
Good luck with the T150. For pics I have used a canon G10, set to "P" rather than "auto" its very compact and fairly easy to use, the macro settings are very handy, as are the different light source settings and the flash controls ( use a lower flash for close macro shots) the pics go to a Dropbox account, then I upload them to photobucket to get the tags to paste into the posts. After a few times its gets quite easy, I write the text as the pics are uploading. To begin with it took me a long time for each post. But Ive got each one down to about ten minutes now.
Posted By: Semper Gumby

Re: alloy barrels for 750 OIF 1971 - 08/29/14 10:51 am

Great Thread Gavin.

"castrol R incense burner" - I love it! I like the way you got the pistons into the head.


Valve noise: Look into the idler gear under the points plate. Remove the points plate and put in the bolt on its own and see if there is movement of the idler gear in the bushes. If the bushings a worn this gear will thrust up and forward (1 o'clock) by the crank gear and the resistance from the camshaft gear. Makes a lot of noise. Replacing this bushing in the inner timing cover quieted the "valve" noise down a bunch. The bush should be flush with the inner surface of the inner timing cover so as to not block the oil return hole between the bush and the oil seal. Else wise you get oil through the seal behind the points plate.

If the bush is worn I would also replace the inner bush which is in the RH engine case. But this is harder to do with out breaking the motor apart. Of course if you had the right puller...
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 08/30/14 6:57 am

Thanks for the good feedback Mr Gumby ( every time I see your user name I picture you with a knotted hankie on your head).

I am not too bothered about the valve gear noise, but I will store this info for later use the next time the motor is in bits, not for a few years hopefully. When the tappet settings get revised down I expect a bit more hush.

Well tomorrow never came for the needle clip changes, the weather was ten tenths cloud with wind and rain, and now family life is getting in the way.
Daughter goes off to University to start 2nd year and we are overnighting in the mysterious East, Then next Tuesday its off to the land beneath the waves for 2 weeks of mid Atlantic weather.
With a bit of luck I may get at the bike on Monday, by the time I get back from Tiree the consumables should be in Oban, the kick start spring and other sundries should get fitted then.
Will resurrect this thread in a couple of weeks time. Cheers
Posted By: TR6Ray

Re: alloy barrels for 750 OIF 1971 - 08/30/14 12:20 pm

Gavin, I've enjoyed this thread all the way through. It's good to see your old friend back on the road and winning the battle against entropy. A mysterious underground lair, rhubarb for re-hab, funny one-liners, new jugs, skilled work, great road pictures -- you worked it all in nicely. Thanks for the story so far.

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 08/31/14 4:12 pm

Cheers Ray,
Its been a lot of fun, and Ive learned a lot more by making it a thread for others to read.
I am glad you have appreciated it. Now back from the East, with one day spare before getting the ferry . If the weather shapes up, ( unlikely) I may get some time for the Beesa.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 09/01/14 2:41 pm

After a ride with the needles dropped ( the original as found condition) and a lot of spitting , banging in the exhauast and general misbehaviour I changed tack.
Working along the lines thar all carb faults are electrical today,the coils were quite warm to the touch after a short run,so I took the meter over various components, first coils, about 3 ohms each across the LV terminals, good, in the Boyer specifications range, noted one is 1971 and the other 1974?! battery, volts 12.5 no load, 12.2 with ignition on, good.
Both boyer pickup coils , 66 ohms, good.
HT leads 12.6 Kohms, that was the best reading they were all over the shop, BAD.
[Linked Image]

All old things were new once, and my new in 1988 leads are now very old.
Spent the afternoon rustling up a set of copper cores leads with 5K NGK resistor caps. I Had to use the 12 year old B8es s because the new B7s had solid nipple tops and the new caps needed threads only. So apart from the 20 over Main jets, the needles are where I found them.

Kicked it up, started well , responds properly to throttle now.
Went for a ride, a huge improvement , normal service is restored.
I am a happy boy, there is a much firmer note to the motor and its now getting on the cam properly.
Its probably too rich at the top end now but theres no time left to mess around today.

So, things to do.

Put miles on, fix the kickstart spring.
Fit the seat hinges.
When I return from Tiree I should have spare inspection covers and a seat catch waiting.
Theres also a pattern speedo head to fit, Although the five quid pushbike speedo is working very well.

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 09/23/14 9:28 am

Now back from Tiree, Ali at North West Motorcycles in Oban had a package waiting for me.

Gerry the Vauxhall Astra man welded up the leaking fuel tank, while it was in his garage I spent some time on the rest of the niggling defects.

Kick start spring fitted, I ended up using the tang on the flat plate inward, outward does not work , fitted outward the tang binds on the outer case.
I used the pull the spring into tension with a bit of wire looped round the outer hook,technique, it took a couple of tries but no blood was shed and only light swearing , pretty much background level with no inventive compound cursing required.

Replaced the missing inspection cover, bell mouth, changed the Main jets back to the original 220s, changed the fuel tank cap for a shiny new one. Replaced the clutch cable casing rubber.
Fitted the correct seat catch ( it is cheap and tacky) and made the new hinges fit, I had to trim about an 1/8"th off one hinge to make the bolt holes line up.
Replaced the gear change rubber ( you would hope they would last more than 300 miles, ho hum, I now have a packet of 5 thanks to Ali).

Of course reversing the entropic decay of the Beesa has taunted the weather gods, having had nearly 3 weeks of Indian summer, now the bike is running we have 10 tenths cloud and patchy rain. never mind.
I put some miles in.
Before setting off I checked the oil level, ( motor not started yet), yup the oil is hiding in the cases , no show on the dip stick. It has sat for 3 weeks so a bit in the sump is on the cards.

Tickle the carbs, full choke and 1st kick start, , goode , time to get dressed, gear on , in gear and off down the drive, stall, bugger, starts up right away and we are off.
Playing with the choke as I leave the village at 30 mph ,it needs the hydrocarbons. I fill up with super unleaded at Crunachy and start it up still with choke, but no tickle, 1st kick no throttle great. Check the oil, there it is back from its holiday to the cases , about 3/4s up from min to max, good to go.
. Head back through the village 4 miles later choke not needed. Heading up Fearnoch hill past a couple of wood lorries I feed it some beans, yup , its pulling well, maybe very well, is that clutch slip at 4,500 rpms in 3rd just before changing up to 4th.?
Possibly. Theres scope for tightening the spring , the clutch is pretty light.

At this point the grey skies start micturating, oh well its still light and patchy. Check the windsock at Connel F2 westerly. I cut the loop short and turn off back down the Glen playing tunes in 2nd and 3 rd. The revised back to original carb settings are doing the business, I still havent had it WFO for long enough to be sure of the mains but everything else in the range is good so for anyone else planning this mod here are my happy place carb settings.

Motor 750 big bore , comp around 9:1.

Carbs, mk 1 concentrics, 30 mm , no air filters , short bell mouths.

Main jets , 220

Needle std 4 stroke ( 2 identifying rings above notches) , top clip notch ( leanest)

Needle jets 106

Slides 3.5 cutaway.

Stock bushed pilot jets 25

Mixture screws about 1 turn out from full in.

Plugs, NGK B8es ( B7s also worked) , Copper cored HT leads, NGK 5 K plug caps, Lucas 6 volt coils, Boyer red box.

Ignition timing ,stock marks strobed at 5 k.

Motor is now pulling well right through the throttle range with no signs of pinking/ pinging. Im not sure if its pschosomatic or not but the 3.5K transition on to the cam seems to be smoother . The only change to the spec as found are the alloy barrels , a slight raise in CR and a very light "flooring " of the inlet ports.

Only 400 odd miles on it so far, so max revs so far has been a brief 5 K, once I get 1,000 miles on it I will start caning it a bit harder.

Generally , everything is fixed, I have tracked down the extended brake arms to " Muttz Nutz", and will fit them over winter , change the fork rubbers and seal and fluids.

Link to extended brake arm "dogbones"

The weather is too poor for pics, but in a week or so I will try for some gopro shots if the weather improves,
Cheers for now

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 09/27/14 3:30 am

Catching up with the latest pics.
A bit out of sequence with the text sorry.
Undoing the cotter nut to flush with cotter top, prior to drifting out

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THe long brass drift helps prevent casing clout.

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Muttz nuts were quick to deliver, new extended alloy brake arms ( dogbones , they call them)

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What do you think of my new oil cooler. ,,joking, part of the "Seas rich Harvest" a fridge cooling coil beachcombed from Port Snoig in Tiree.

[Linked Image]

New extended brake arms fitted.

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More go and more slow, the extended arms are good quality, for an extra 20 quid they can come polished, I bought the raw versions.
Result, a much firmer feel at the brake lever, with more brake for less squeeze, an excellent mod so far, works better , looks better, and saves a bit of unsprung weight.

Miles are adding up slowly, the motor is spinning up well, no oil consumption, or negligible at least. A run into town yesterday went well, testing the new brake arms, I had taken all the slack out of the brake cable,leaving a very firm feel to the lever, with little or no give before biting hard.
When I got into town I eased the adjuster in a couple of turns so that the bite came closer to the bars. Nice feel.
The weather was mixed , I got soaked going in, and had a cuppa with Ali while I dried out. The bike is now starting and idling well, choke is needed for about 2 miles, no more stuttering or spit back, Answers the throttle well, and blasts from one traffic knot to the next on a waft of easy middrange torque. Brakes are now up to the motor. Hurray.
I am now pretty satisfied with the initial trouble shooting, hopefully the next run will be a decent 100 miles or so, there is a nice local loop taking in Glen Coe, good for photo opportunities,When I finish this run of shifts I will go for that if the weather gods are not too angry. May take a run over to see John Jill if the East beckons.
BSA really pushed their luck naming these models Lightning and Thunderbolt, I reckon they had a deal going with Alistair Crowley.The beast himself.
Still to do,
fit new fork gaiters and headlight rubbers, fit new speedo head, ( the cycle speedo is brilliant and is handy for the running in miles , so the new speedo head can wait)

Posted By: Allan Gill

Re: alloy barrels for 750 OIF 1971 - 09/27/14 12:01 pm

Great work there Gavin. Glad to see the carb issue (/ignition issue) is all sorted. Ignition problems end up leaving you hunting around like crazy trying to fix a carb which isn't broke.

Whilst on the Belgium Summer Camp I was having some problems, and trying to get the carbs dialed into it became tiresome. Like you it was worse at lower throttle openings, it seemed ok on full chat. Until eventually it started acting like it wanted to just crap out. Turned out the pickup plate on my Altair (Pazon) had decided to break down. It got a temporary fix to get me home and I re-fitted the standard Sure-Fire unit which (touch wood) has never caused me a moments itch. In the process I had ditched a couple of good plugs and a very good battery. ( Still need to Email Pazon about this! Good job it has a 7.5 year warranty wink )
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 09/27/14 1:33 pm

Cheers Alan, carb faults , electrical faults, its all sent to try us.
The boys woke me up early from my night shift kip today, the weather was dry!, so I took a chance on a Saturday afternoon local run, up to the Creran loop, ( Imagine David Attenborough narrating), hushed tones.
"here we see the Mk5 Spitfire 750 in its natural environment, years of evolution have lead to a very re3fined two wheeled creature.
[Linked Image]

The mark five likes to hunt along remote sea shores, preferring the tortous bends of an inlet sea loch to the flat plains of the central belt
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A potential meal for the hunter
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Robbie snorkeling in Loch Creran
[Linked Image][Linked Image]

The mark 5 gains altitude to spy out new areas, for Python fans this is just above Castle Stalker which featured at the end of the Holy Grail movie.
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Lookin good
[Linked Image]

After wearing down its prey the Mark 5 heads to familiar eating territory, the George street chipper in Oban, that old guy on the right was very "relaxed " and had the nerve to swick the que in front of me!. I took his picture and told him his photo was going in "The Book ".
[Linked Image]

Price list for fish supper connoisseurs, this place tops the other two in town.
Of course I had to cane the bike back home to keep the fish hot for SWMBO.
[Linked Image]

No issues with the bike, and gaining familiarity with the old thing, loving the flywheel gyro effect and the rock solid lines no matter what the road surface is doing.Looking forward to chamfering the pegs soon.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 09/29/14 1:55 pm

A good warm day today, clear patches in the sky and large fly hatches, dry roads .

Fitted the pattern speedometer head today, the old one is a matching ( with the tacho) grey face, its going for a refurb. The pattern one works very well, its a bit twitchy but nice and visible compared to the cycle speedo.

Took up 3 flats worth of slack on the chain adjusters to stop it flapping around.

[Linked Image]

The miles are mounting up, after cleaning the headlight bucket and fitting new mount rubbers I looked disconsolately at the wiring in the bucket , it needs a new rear rubber and some fresh connections wouldn't go amiss, the main earth return connections were ropey to say the least , my fault , I found one slack earth in there so it was worth a look.

I may rewire it, the new in 1985 loom has seen better days, although everything is working at the moment it could be a bit tidier with no extra indicator cores.

The old imperial male connectors are all showing bare copper to their rear ends , horrible.

Warm and dry, I took it out for a 59 mile run.
[Linked Image]

The odo says so.

With about 400 miles on the cycle speedo and a few more when it wasn't connected , I started upping the revs and working the motor harder. What fun. The clutch isnt slipping, the motor does pick up well though. There was a strange moment when the carbs got out of sync after a stop and restart where one of the cables got hung up by about 2 mm, weird, it still ran pretty well though. An easy fix, I had put self amalgamating tape around the cable rubbers to seal them and some got where it shouldnt be, somehow, probably after disturbing the headlight.

Using higher revs means more heat , the oil tank spine is now getting too hot to touch for more than about 15 secs, plus 55 C approx. The oil light now flickering at idle when warm. It did that before so I am not too worried, straight 50 would stop that ( ho ho).
My tea is out. More later.

I have some spare handlebars lying around, the tomassellis may be coming off for a change.They force the speedo cups in so they wrestle for space with the lamp bucket, they weigh a lot compared to stock bars. Planning on fitting a fly screen . The flies were grim tonight, a couple of times I thought it was raining!

The clutch lever needs replaced, its taken one too many fall and doesnt lie coaxial with the bars any more.
One more for entropy.

Posted By: Adam M.

Re: alloy barrels for 750 OIF 1971 - 09/29/14 8:30 pm

Really envy you these open roads, here in Toronto traffic never stops.
Took part in the Distinguish Gentlemen Ride yesterday - most of the ride on first and second gear on broken asphalt and tram ( streetcar ) tracks with big group of people mostly on old Japanese bikes.
Beeza were on her best behavior, starting from the first kick every time, holding idle on a very hot engine, going around corners with grace, braking hard without fading and being pretty peppy when necessary, but it was hard work for me and the old lady. When we finally got home I checked the oil and it was close to nothing in my tank.
Not recognized by old and young bikers in the beginning of the ride, she got lots of thumbs up and positive comments during later stages.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 09/29/14 10:34 pm

Hey Adam,
Open roads,
caravans, 40 mph, dickheads everywhere,

people who have never seen a corner in their lives,

brake lights .

I swear; some people come here to learn to drive.
Still better than the city though,
my condolences,

When i said earlier that the oil consumption was close to negligible, that was open to interpretation , after about 250 -300 miles its used about 1/2 a pint or so ( this fits with old time use , stick to 60 and save , use it and lose it,
forces, pressures,and speed.)!),
enough to move nearer the bottom of the dipstick.

My previous experience is , stick to 65 , it sups along, open the taps after that and the consumption goes up. My motor is smooth about 4,500 - 5,500 , that's too fast in 4th( for our speed limits) most of the time ,
enough to start beating the timed engine breather..

Most fun is to wind it out in 2nd Waiting for the engine to explode
then short shift 3rd to fourth. The launch from the flywheel on up change is elastic.

Old time poster, "Panic" used to have a thing about this, "flywheel weight kills acceleration,", it does on the A65 but it pays back in other ways . Very different from a light flywheel. My Cagiva only feels the same giro effect if I use double the revs.

after riding my other bike around similar venues and close / slower speeds , I feel the A65 is out of its time, too loud, too slow, but what a blast! I am still grinning.
Posted By: Adam M.

Re: alloy barrels for 750 OIF 1971 - 09/30/14 12:22 pm

Yes, you have to wait for this heavy flywheel between 2 and 3500 rpm, but when it starts moving above 3500 my bike has turbine like acceleration and yes it feels great and very responsive in 4500 - 5500 part of revs. On second I take it to the 7k sometimes just for the thrill of it - feels like a rocket on wheels. All this on nice empty secondary roads around west of Toronto, nothing like this is possible in town.
Unfortunately this type of fun riding cost you in oil, gas, and broken brackets - after 2 seasons of riding with a small port head vibration of my engine got gradually worse to the level of being uncomfortable - so I wonder if my crank is getting loose in the cases, or perhaps my shock absorber is getting worn making clutch basket wobbly.
However oil pressure is better than ever, and clutch works without any problems.
Posted By: Allan Gill

Re: alloy barrels for 750 OIF 1971 - 09/30/14 3:30 pm

Adam, have you checked the engine mounting bolts? Any slight movement and it will vibrate something rotten.

Keeping in conversation with the small ports, if you still have your original cylinder head, you want to try filling the port floor, 10-11mm reduction by the guide will make one hell of a difference. I found even more success reducing the ports on the small valve/port head.

The unmodified small port head would see no higher than 8 in second gear and short bell mouths. Following the port reduction on the same head ( only difference was the race springs)I fitted air filters ( because of all the rain I was expecting at the IOM MGP) and in second, going uphill I was seing 8500, and there was more left to play at, not wanting the see the internals of the engine that week I changed up a gear instead.

Point being, the vortex is so great that it is still drawing mixture in long after a larger ported head would. It handles taller gearing better and accelerates fantastically with the increased gearing.
Posted By: Adam M.

Re: alloy barrels for 750 OIF 1971 - 09/30/14 8:05 pm

Certainly I checked all the external possible places, but everything looked solid.
And I know my bike could be really comfortably to ride with some vibes down in the rev range, but very good with higher revs. Unfortunately now vibration is really bad all the time, so something really changed. I never changed my rubbers in shock absorber ( they looked rally good and tight 7 years ago ), so I hope they could be a culprit.

I'd consider playing with a head further, but I bought a 73 T150V and am going to start rebuild shortly ( just got a call from a machinist about my crank being ready to pick up ) so I think it'll take most of my free time. Aside from this, I still have to go back into my BSA head to repair what is there done not properly ( valve seats are cut with a sharp edge left there and not chamfered, and somehow oil is seeping between guides and head ). So winter looks busy smile.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 10/03/14 8:51 am

Hi Adam, really bad vibration all the time suggests something somewhere is loose, either a cycle part or somewhere in the motor, I dont think it will be the clutch cush drive, although perhaps a badly worn primary chain or the like.
Cracked mudguard/fender, loose header , loose headsteady , loose tank strap that kind of thing.
Best of luck.
Posted By: Adam M.

Re: alloy barrels for 750 OIF 1971 - 10/03/14 5:02 pm

Thanks Gavin,
this vibration comes from the engine and makes all the bike vibrate a little more than in the beginning of the season making ride less comfortable.
I have to check a crank clearance in cases during winter.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 10/06/14 6:29 pm

Adding the miles today, 500 mile oil change completed, light contamination of magnetic sump lug, same as before. Pics to follow.

Running on wet roads through showers of rain today, never missed a beat.
Noted the telltale rainbow sheen of diesel all along the west bound route, so took it pretty easy heading in to town.
Asked Ali ( West Coast m cycles) about possible spares , no easy source of front wheel spindles. Will google trawl for a new one later.
Starting first kick all the time now. From cold , tickle plus choke, from 1/2 warm either tickle or choke gives a first kick result, choke is handier and cleaner.
Steady speed revs now rising to around 4 K. The motor is picking up very cleanly right through the range. The last time I pulled the plugs , both showed a reasonable tan colour, been using "super unleaded" 97 octane from the same pump .
Next oil change I will pull the filters for a close look ( I hate doing that , its not user friendly)

I read J Healeys excellent treatise on setting up carbs and noted that my float bowls are fitted with 0.062" fuel valve orifices. Which, according to his literature, are incorrect (correct fitted to pump fed two stroke float bowls) , this may be why the ticklers are a bit slow to flood, I have new float bowls with the correct feed orifices on order. These are the original( as I received the bike) and possibly wrong float bowls, there were some hellish bodges on it when I first got it.
Posted By: JER.Hill

Re: alloy barrels for 750 OIF 1971 - 10/07/14 10:57 am

Hi Gavin

I have a pair of old 32mm float bowls here, measured the supply bore and it was 0.100" using my small drills. There exactly the same size as my other 32mm carbs. Your welcome to those, let me know if you want them and I'll bring them back to Jockland with me.

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 10/07/14 4:15 pm

Hi John, sounds good, deal me in, finishing NS tomorrow morning ( Wednesday), only 22 more to go , woo hoo.

Found a front wheel spindle and some odds and ends on Ebay.

Put some more miles in today. Running around B roads in 2nd and 3rd, trying the front bake for max stopping, its better but still no disk. May try new front brake shoes later.

A gorgeous sunset, with dry roads, southerly gales coming soon though, lots of leaves coming down , the back road down the glen has been visited by the gravel fairy, the road menders have been out sprinkling 6mm granite on all the racing lines, quite a challenge, road men are allergic to brushes, in the way that electricians are trained to deny dropping cable ties.
Posted By: JER.Hill

Re: alloy barrels for 750 OIF 1971 - 10/07/14 6:56 pm

Hi Gavin

I'll get them ready for coming North, they are the older style without the drain plug in the bottom of the bowl.
Better keep off the loose stuff when trying out your front brake, don't want to see you with gravel rash.

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 10/11/14 1:17 pm

Gave the bike a clean, found the LHS silencer clamp was a bit loose, nipped it up and cleaned the wheels.

[Linked Image]

Tooks some pics at the "Apple day" at the poly tunnels

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Sump plug from last oil change,

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clean barrels
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The nights are fair drawing in now, but the roads are now empty so I plan to get a few more runs in soon if the rain holds off.

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 10/12/14 11:00 am

What a day, flat calm, 5/10ths cloud cover. Quiet roads, saw 3 cars in 26 miles of Loch Awe B road.

Kilmaha view point

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Checking the Livestock
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The stone in the background used to be the tallest standing stone in Argyll.
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Untill the lightning hit it
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Fillerup, beside a black MV
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Weird bairn and dpg at a yard sale
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Chicken strips are going
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Having fun today, brakes are good. Motor is good, a bit rough at 5K though.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 10/16/14 1:13 pm

Cleaned around the plastic bits today with a Vinyl restorer potion, also shined up the front wheel.

Dry roads with leaves and gravel for that extra edge.
Southerly gales imminent.
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Took a run to Kilchrenan, for the corners .
Barachander bend
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Barachander run off farm
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Glen Nant , river on the right, Oak forest
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Cleaning around the front wheel there is perceptible movement at the spindle, the new one will go on soon.

Motor running well , though some fine balancing of the carbs is on the list of things to do along with closing in the tappets.
Posted By: Adam M.

Re: alloy barrels for 750 OIF 1971 - 10/16/14 8:35 pm

These roads Gavin look narrower than in Poland smile.
Took the BSA out for a few hours in the middle of the day, temperature still around 18 - 20 C but not enough time to go out of town, so just spent the time city driving. During the ride I found out engine going rather rough and tickower fluctuating but quickly realized my air partially closed.
After correcting this everything came back to normal.
Had a very entertaining ride in afternoon traffic, with cagers hurrying home for dinner smile.
5 min after I got home real torrential rain started and it rained for most of the evening.
No pictures though.
Posted By: old mule

Re: alloy barrels for 750 OIF 1971 - 10/16/14 10:49 pm

It is good that you did not purchase the child and dog. In my country is not allowed those things at garage sale!
Posted By: TR6Ray

Re: alloy barrels for 750 OIF 1971 - 10/16/14 11:10 pm

Gavin, those are some really good pictures of what to me is an exotic bike in an exotic land. It sounds like you are getting it dialed in well. Looking at those narrow, blind curves, I have to admit that my chicken strips would still be very evident. I'm always worried about what I'll find around the curve.

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 10/17/14 3:49 am

Thanks gents,
The child and dog stayed behind, I did get a 2 ft steel rule, a bike cover and a sugar thermometer for a fiver though. I passed on the optional decorated Donkey collar.

Ahh, the bends, there are very few straights in Argyll,corkscrews, changing radius, sweepers, chicanes, all sorts of corners are varied and plenty, some of the best are "shell " gripped, usually where Road Traffic Accidents dictate the surface needs improving.
The pics above at Barachander are on an amazing road.

Heading South out of the village , your first challenge is a 1st gear hair pin that climbs 40 feet in 50 yards with a 270 degree twist, followed by a sinuous roller coaster over to Otter Creek, with clipped apexes, into the wooded glen following the river, blind single track with passing places, , then up to the quarry with fresh smooth tar round a crenelated hill top, down the 4 G dip with suspension bottomed , then a fierce climb in 3rd to the Barachander bend overlooking loch Tromlee and the Ben.
Thats just the first 6 miles,
The Auto mobile Association Book of the Road, describes the west side of Loch Awe B road , my part, as the "greatest roller coaster ride in the UK", about 39 miles from here to Ford. Its so strange that a lot of the locals here never use it, , single tracks need a different mindset.
I find it hard to get good pics of my favourite sections, really need a helicopter /drone to do it justice.
We have some of the finest roads in the world, but they come with their own difficulties, gravel is number one hazard. Then 4WDs driven by numpties, then sheep and deer.

The BSA is well suited to this terrain, playing tunes in 2nd and 3rd, the mid-range torque makes blasting around very simple.The suspension copes well with the choppy patched surfaces.
The OIF is a sweet handling chassis, I like my weight well forward for cresting the rises hence the weird bars, about 4 inches forward from stock, the rear sets need moved back an inch or so, but they give a much better position than stock.

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 10/17/14 12:39 pm

More miles, more pics,
filling station at Benderloch

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135 miles for 14.99 11.54 litres equals 53 mpg, woo hoo, thats 135 miles of very mixed riding with 50% 3rd and 2nd gear.

Pleased, should be able to stretch that to 60 mpg on a steady cruise.

looking down Glen Shellach across Loch Etive to Taynuilt (my village.)

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The last remains of an ancient Yew forest , two lonely old trees.

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Ardchattan priory
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Sun going down over that western hill, looking over to Achnacloich

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Took the bike into Oban to see old time racer Neil, he was impressed by the oil tightness, we talked of the Hogg brothers and days gone by.
An old west coast chentleman came over , attracted by "the beat " of the old motorbike.
Dry roads , more gales and rain coming overnight.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 10/18/14 4:22 am

The last fuel stop was for regular unleaded, by abusing the motor in 3rd on a steep hill at low revs and wide-ish throttle openings I was able to create pinking. My fault for labouring the motor.

So, I guess the timing is about spot on. It hasnt moved for 11 years. Apart from the clutch push rod and the kickstart spring nothing below the barrels has needed fettling.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 10/28/14 5:03 am

Decompressing after nightshift, no riding due to torrential rain.
Ive compiled s list of stuff to do/ get for the bike over the Winter.

Fit new front axle, and maybe tidier ex MZ 250 H bars.

Fix the footrest position.

As it is the up-change is easy , however going down the gears needs a very fine toe or a back heel. The back heel is fine going into first but is not that easy when howked over in the bends going 4th to 3rd or 3rd to 2nd.
I dug out an old set of Converta alloy front mounting plates from the Norbsa, I have cut them into a sort of inverted L shape, with 2 mounts to fit onto the old stock footrest mount and an additional hole where the existing rear set peg is mounted, I have left a tail on the plate running rearward which I can mount a revised footrest on about 2 inches further back.

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I spent some time spot finishing the plates using a wooden dowel and some grinding paste , the effect is quite pleasing.

Buy Barleycorn rearsets, , a folding peg for the RHS and a peg with lever coaxial for the LHS brake.

Buy a scrambles type kickstart which tucks in, the existing kicker occupies a space where my shin bone wants to be.

Cut 2 inches off the Later Triumph type centre stand so the front wheel is not 4 inches off the ground when on the stand.

Buy an undrilled SS T140 rear mudguard
make a lower mounting bracket to pick up the rear motor mounts and fit the 68 rear alloy light and new number plate.
The old mudguard is splitting and it fails to prevent road muck from going over the top of the swingarm pivot. .

Get pre focus , QH head lamp bulbs ( Paul Goff) to whiten the warm glow from the H lamp.
A relay is also on the list.

Get the fuel tank painted, time to look up some old mates.

Most of this stuff is just a few keystrokes away, so money will be spent over the next day or so.
Ive found this rebuild far easier than previous, theres some good stuff available out there now I had never heard of before.

The bike will get ridden if the weather gods allow, before all this stuff starts appearing
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 10/29/14 1:45 pm

No rain today,
theres been about twelve inches since the last run, see pics

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Entropy 1 BSA 0. The centre stand RHS bolt has vanished, the bike looks better leaning .
Ordered Kick Start , ( scrambles type, and alloy gear lever).

While speaking to Terry about the Kicker he mentioned a Metiise kit , frame and plastics ,tank etc for 2000 I was sorely tempted , my bike is fine, but what a deal, he will re stamp the old frame number onto the new chassis to keep things sweet.

Got a quick reply from Simon at Barleycorn, he has what I need for rearsets.

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Could be the last time this set up is visible.

Visiting the LBS leaning tree up Glen Lonan.
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The bike had wet sumped while parked up, took about ten kick and two tickles to fire up with a bit of smoke from the pipes while the sump cleared, ran fine after that.
Another job for the winter, the clutch is slipping a bit when its cold , an extra turn on the clutch spring screws should fix that.
Working on the footrest plates at the moment.
Posted By: No Name Man

Re: alloy barrels for 750 OIF 1971 - 10/31/14 6:34 pm

Very nice Gavin...I was going to ask you what you did to the centerstand to make it lift the rear...then you answered before I could!

Bill E
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 11/01/14 7:35 am

Bits have started appearing,

SS fasteners from D Middleton within 24 hrs,2 1/2" x 3/8" UNF SHC screws with Nyloc nuts for the footrest plates .

Float bowls from John Hill with the correct size fuel feeds, Thanks John Hill and John Healey for the info.

Waiting for the footrests from Barleycorn.

Ali at North West Motorcycles is getting the new rear mudguard and centre stand bolts.
This may take a wer while, he needs more mass to his orders to avoid punitive postal charges and make a bit of profit.

The gales have brought all the leaves down, theres not much of Autumn/ fall left, salt will be on the roads soon, the bike will get parked up for Winter after that.

I had a good chat with my old mate Kenny Durward who painted the tank and panels in 1981 , he is happy to redo this work , so the tank will have a Holiday in Forfar over the Winter.
We also talked about having the side stand tab repaired. KD was concerned that this is done with adequate preheating to prevent stress build up. Makes sense. Perhaps a job for the bikes 50th anniversary in 2021.

Posted By: Allan Gill

Re: alloy barrels for 750 OIF 1971 - 11/01/14 5:47 pm

Hi Gavin, what is different about the new float bowls? Amal will sell directly high flow bowls ( I think the feed hole is .125" from memory std being something like .100". I have a BNIB set myself of these but have yet to run into the issue where I need them. I'm assuming this is what you have ordered?

As for the bars, have a good look at the norman hyde M bars, Roger G posted a photo in my resto page, I've just clamped on a set to my bike, beauty is you can fit them either way up depending of if you want a dropped bar, or slightly raised but with the grips still aiming down wards.

I'll try and get a photo of mine tomorrow to show.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 11/02/14 8:44 am

Burlens delivery time was 6 weeks!

The old bowls have restrictive 0.062" feed orifii ( sp?) , per Mr Healey these are for pump fed two strokes, not really my thing.

The bowls J, Hill has sent over are fitted with orifices ( SP?, covering all bets here) of approx 0.125".
Currently my ticklers take about 10 -15 seconds to prime, depending on head. thats why I want the greater feeds. I dont think the old ones restricted fuel flow too much, never holed a piston, but we will see what changes with the new ones.

As for bars, I have MZ bars on the shelf, they are excellent quality and about the width and rise that I like, they can also be fitted upside down., or indeed back to front.

Posted By: robcurrie

Re: alloy barrels for 750 OIF 1971 - 11/02/14 9:58 am

Gavin, you left out another possibility: orificia. Maybe it will be easier to stick on a single carb. grin

Rob C
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 11/02/14 10:56 am

Cheers Rob, thats a good one.
Thunderbolt head for etymological reasons, why-ever not!
Posted By: Pete R - R.I.P.

Re: alloy barrels for 750 OIF 1971 - 11/03/14 10:00 pm

Originally Posted by robcurrie
Gavin, you left out another possibility: orificia. Maybe it will be easier to stick on a single carb.

You'd have twice the fuel flow problem, with only one carb. It's much easier to get a fuel supply through 2 inlet seats than through only one.
I'd be concerned if the combined fuel flow was much less than 600 ml/minute, as measured out of the float bowl drain plugs with the fuel turned on.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 11/04/14 8:02 am

Thats good point Peter, before I swap the bowls, I will measure the flow rate of the system currently fitted as a reference for others.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 11/05/14 11:50 am

Rear set parts from Barleycorn,

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Brake lever and footrest

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Brake pedal peg and assembled lever

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Complete LHS with footrest mount plates

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Test assembly, good no interference .
Plate needs final mount hole to be drilled

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Showing brake pedal stop and plate to frame spacer.

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Both plates loosely mounted with rests
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Took the bike out for a run, clear blue skies and low sun, no one tried to kill me today, most unusual.
Ice on the puddles this morning and salt on the road, last run this year I think.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 11/19/14 2:11 pm

Dry roads, took the bike out,, Go pro vid coming up , , last fill up, 147 miles at 53.7 mpg.
Pretty consistent.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 11/21/14 4:41 pm

you tube link

trimmed a bit from the go pro, my back road

look around after run
Posted By: shel

Re: alloy barrels for 750 OIF 1971 - 11/21/14 7:00 pm

The bike sounds strong, Gavin
Posted By: kurt fischer

Re: alloy barrels for 750 OIF 1971 - 11/21/14 7:53 pm

Really great, Gavin, now I have something to aim for.

BTW, that's a dry road? grin
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 11/21/14 8:43 pm

Its as good as you get in November in Scotland, tragically, the highland ladies were missing. Will put up more but its quite a faff , that clip took a whole afternoon of pusssing around.
Posted By: Adam M.

Re: alloy barrels for 750 OIF 1971 - 11/21/14 8:54 pm

Yes, bike sounds super strong, roads are wet and scary looking, your speed much too high for me ( I realize you know it well ), postie looked really surprised to see you smile.
Posted By: bon

Re: alloy barrels for 750 OIF 1971 - 11/21/14 9:08 pm

The bike looks and sounds great in your videos gavin, as does rural scotland. I'd love to be let loose there with the .243.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 11/21/14 9:47 pm

the go pro makes it look scary, it distorts in a weird way, the hills are levelled out and the corners are straightened, the motor was in 2nd most of the time, revving to 5k max , mostly 2,5K to 3.5 when its starts getting raspy.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 11/22/14 3:45 pm

Got the bike ben the hoose, for a review of the RHS rear sets.
SWMBO turned into SWCBQRS ( she who can be quite reasonable sometimes) and granted comfy working conditions.

Old RHS folding footrest with bodged spacer because the mount was too long

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470 grammes

New arrangement prior to trimming to fit

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500 grammes.

kicklevers folding trials and stock, length comparison
the trials type is longer

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lever weights
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The new one is heavier and needs a cotter with more bevel, which I dont have yet, I bought one , but it is hiding somewhere.

Lever and gear pedal are kissing cousins at the end of the stroke, the old one does this as well so it will be going on when the cotter emerges. You can see the old original mount hole and the old rear set hole, they are 2 inches apart, The new peg sits 1 inch and 3/4 to the rear of the old one.

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Measure once cut twice they say, not me , dont measure and trial fit a dozen times, final result with mount plate trimmed all round, lost 50 grammes so it now weighs less than the old set up.

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Before trimming, the rear hole was too far back.

After trimming

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The new peg is around 20 mm more outboard than the old one, I can lose 8 mm off the spacer pieces and about 4 mm off the footrest mount boss, a trip to the lathe required.
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The lightweight alloy gear pedal( not shown) is cute, but doesnt work when reversed.

It needs a crank in it to clear the kicker.. Maybe later.

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Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 11/27/14 5:48 pm

More work on the rearsets, spent the afternoon and a few evenings make the LHS plate fit like the RHS.

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I had to advance the operating arm against the pedal by one set of holes to put the pivot point co axial with the swingarm spindle ,it also uses a tidy rose joint in SS rather than the old rusty and worn clevis.

I have a plan for the brake switch, if I mount it further up the frame tube abd take a tab from the rose joint locknut I should get it back in service.

Made two pairs of spacers , shorter for the RHS and longer for the LHS so the brake pedal clears the pipes.

I was able to use one of the LHS mount bolts as a pedal stop with a spacer to put the bolt head proud.
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This saved using the supplied stop which fits behind the pedal but moves it outboard. The old foot rest was a lot shorter and had loads of clearance.

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Not a bad wee project, apart from the cost of the new pegs and pedal , the plates were buckshee and the fasteners were beer money.
For anyone that fancies copying , heres what I used.

The plates are ex converta dural engine brackets, surplus to requirements, hacksawed and filed to shape from a carboard template.

4 off SHCS 3/8th UNF bolts and nyloc nuts.(3 x 2 and 1/2 " and 1 at 3 " )if you want a stop for the pedal)

4 pieces free machining alloy rod about 20 mm diam (2 x 27 RHS , 2 x 34 LHS) mm long , , one is oversize OD but thats not important ( I had some stock and it helped cover the frame holes) all drilled clearance for 3/8th nominal.

The mount hole centres are 2 inches apart on the frame, I used a previous upper hole which used to mount the old Pegs directly, the plate has a footrest mount 1 inch and 3/4 back from the upper mount bolt giving room to operate the gear pedal.

Sorry about the mix of measures but thats life in the UK..

The new rear sets come out a few grammes lighter than the old steel footrests and look a bit less ropach.

The brake pedal stop now needs a longer bolt and I am compiling a list of new fasteners needed to fit the new rear mudguard/fender and earlier alloy rear light.

The RHS from above with shorter spacers, I opted for a normal hex set screw to mount the footrest and trimmed the head on the lathe to give a can scant eighth or so between it and the frame tube.

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Once these rear sets are done I should have the bits for the rear fender / light.
Of course it wasnt all plain sailing, the rear brake adjuster has stripped its female thread, and is in the entropy pile now.
Also going to fit the repop side panels , to be painted to match the tank when KD gets it over the Winter for a tart up.

Im thinking Big BSA star decal on the tank, and lightning logos on the panels, I love the Spitfire decals but they were one off vinyl jobs and the guy who made them is a sail maker now not a signwriter. Open to suggestions or criticism on this, fire away.

The weather is poor at the moment, the sun barely hits the glens for about 2 months from now.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 11/27/14 6:46 pm

List of possible winter jobs.


Check the fuel flow and fit higher flow float bowls if necessary.

Look at the clutch spring settings, its light theres room for a turn or two.

Look at the oil pump check ball, its not seating.

Fix the manifold oil leak and fit new pipes.

Revise tappet settings to 4 inlet 6 exhaust.
Fit air filters and oil filter.
Revise oil return, blank off rocker feed at manifold and redirect with T after oil filter.


New front wheel spindle.
R mount Brake switch, make new rear rod adjuster.
Buy new Side panels . Paint with tank.
Fit new rear mudguard and light unit.
Paint rear brake plate , touch up chassis , maybe strip yokes and paint( confession, I have never looked at the steering head bearings, its never needed it , probably about time to re-grease!).
Trim seat catch, the hook is too long.
Change fork oil.
Fit new speedo bracket and cable, the outer is trashed on the existing item.( entropy split)
Change bars for lighter set.

Re wire , with custom loom,and dual output coils (I am suspicious of the sheer age of the old Lucas 70s 6 volt cans as fitted, this could free up a lot of space under the seat, maybe a neater battery too. The wiring has mouse damage and is getting on, will re place with Japanes style connectors and some decent fuses and relays for horn and lights, Paul Goff (SP?) in the UK does prefocus fitting lamps with halogen conversions, thats a must do, the Head lamp has a warm glow at present, fine for a candle lit dinner not for riding.
Posted By: old mule

Re: alloy barrels for 750 OIF 1971 - 11/27/14 10:55 pm

Very nice machine, The VMCC has transfers from any era of BSA production.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 12/01/14 9:53 am

Trial fit of new fender , its a repop in SS for a T140, undrilled.

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NOS rear fender, not going to be used but showing off square lower end which prevents a good fit.

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Showing NOS dimensional instability and blown chrome.

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New fender weight 1.316 KG

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Old fender weight 1.763 KG, 447grammes heavier.

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68 rear lamp weight 510 grammes

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71 rear light weight 778 gr, 268 heavier.

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NOS on top T140 beneath , radius differences, I need a spacer for the lower mount to work.

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NOS top
Repop t140 middle

Universal, shorty lower

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Some useful weight savings. Fender - 447 grammes at least, Rear lamp 268 gr, total 715 grammes.
Some of which I will lose by fitting the lower mount bracket and spacers, some I will win back by drilling mount holes.

The old fender was splitting at the rear lamp number plate area and had a few unneeded holes from other lamp fittings. It never had the lower mount. It also fitted with a spacer under the passenger loop cross-member and caused the rear grab rail to droop a bit. Hoping to win a straight chassis line here to run with the side panel frame straight line.

Now for the noisy bit.

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 12/01/14 11:37 am

A quick check with the back wheel refitted shows enough clearance for the new fender to work OK, I now need to make up the 45 mm gap between the fender lower end and the lower mount bracket, the rest fits OK, coming up to the mount tabs with no spacers needed.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 12/02/14 9:25 am

I have ordered 1 metre of 3 x 20 mm SS flat bar to make licence plate and lower fender mount brackets.

Trial mount 68 lamp, new T140 fender
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An unexpected package arrived in the post, carb parts ordered from Burlen ( I thought I had cancelled the order) , so much for 6 weeks delivery, 3 months !
One thing leads to another, the rear light wiring is possibly the spur to complete a new loom, off to check sources of wiring bits next.

LHS rear set final assembly. I ditched the mount bolt stop idea , it left the lever at too agressive an angle, this meant I could use the shorter mounting spacers, shorter bolts , this uses the supplied lever stop. The flash shows rust on the RHS rear silencers, nust deal with that.

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Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 12/07/14 12:22 pm

I marked up the SS flat bar with mashing tape

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and had at it with saw , files, drills, hammers and vises,

ended up with 2 number plate mounts and a lower mount

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The lower mount , still needs trimmed.

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, birthday whisky, a wonderful dram.


Found these on the shelf in the shed, for some reason I had discounted the idea of these because I thought there would be too much error for the hose, it turns out that the hose can be pushed into the air box by the offset of the manifold stubs , now sealing on the tapering section, this is workable . Stock filters are going back on.
I will buy spare inlet hoses and try cutting a section out and re-gluing, shortened style.

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Another test fit of the guard,,, hot tip , drill generous clearance holes to allow some movement, there isnt much room at the lower end, I need to trim some to prevent the chain guard saying hello.
Posted By: kurt fischer

Re: alloy barrels for 750 OIF 1971 - 12/07/14 9:40 pm

Gavin, the '68 taillamp looks good, I really dislike the sheetmetal affair of 1971-1972. (I've got one of those '68 lamps on my Triumph Bitsa.) Took me a while to find the correct BSA chainguard, to replace the Triumph one I found on ebay advertised as Tri/BSA.

My riding here is curtailed a bit, either we have 50F and deluge, or dry and below 40F or below freezing. Or just above freezing and light rain. With wet leaves on the roads. Have re-stocked on Glenlivet as well.
Posted By: Ger B

Re: alloy barrels for 750 OIF 1971 - 12/08/14 2:09 am

the hose can be pushed into the air box

On the T-bolt, with one carburettor, the hose is a rubber casting with a rim that catches the airbox.
Would the Lightning not have a similar kind of set up?
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 12/08/14 8:49 am

Hi Ger, what you dont see is the air intake rubbers, part in the airbox, the lipped section is now pushed in about 30 mm, its not ideal, but it gives me something to work on. I may try molding my own adaptors , .
Posted By: Ger B

Re: alloy barrels for 750 OIF 1971 - 12/08/14 2:15 pm

Gavin, I think your carburettors are to far away from the head.
On pictures I find of Lightnings, the carburettors flange directly onto the head.
On not any (is that English?) I see the rubber which you have between the head and the carburettor.

Could that explain your 30 mm?

I would scan some pics from a book I have by Mathew Vale, but since I converted to Windows-7 my scanner does not work any more. mad
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 12/08/14 3:53 pm

Yup, my carbs are out on rubber manifolds , one of the reasons its run without filters up to now.
Posted By: Allan Gill

Re: alloy barrels for 750 OIF 1971 - 12/08/14 5:11 pm

The original bike would have had 5mm tufnol spacer between carb and head... which is completely in-adiquete for keeping the carbs cool enough not to falter in traffic. Gavin's attempt at a solution should be quite welcoming to those wishing to use a thicker spacer between carb and head. I think it also looks quite neat.

I would wonder if the rubber where it sits within the cutaway on the case has a reasonable gap around them, then maybe just cutting the lipped section off, sliding it around the hose so it locates again in its rightful position, then trimming off any excess.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 12/08/14 9:00 pm

I am thinking that way , I am stuck with the carbs on the spacers, rubber manifolds, the convenient taper fits in well, its got to be better than breathing in road grit.,
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 12/12/14 8:48 am

Carb inlet rubber cut and fitted

[Linked Image]

Showing the two parts at the sanding machine
[Linked Image]

[Linked Image]

10 mm stub on airbox side
[Linked Image]

Inner side of cut radiused for bell .
[Linked Image]

Carb side radiused to help ease fitting

[Linked Image]

Showing over lap
[Linked Image]
[Linked Image]

Final fit is tidy.
[Linked Image]

Brake switch striker , mark 2, mark 3 to follow, the slop in the rose joint allows this to miss the switch, a wider finger pad is needed.
[Linked Image]

Old rear number plate mount, missing large vital areas, a bit on the flimsy side.
[Linked Image]

A bit out of sequence,
the useful step drill, great for drilling fender/ mudguards

[Linked Image]

Dark days, a good time to be footering about indoors.
Day 4 of "fitting " the rear fender,, the lower mount is on the mark 3 spacer arrangement.
Mk 1 , washers, ugh, Mk 2 , a taper washer, wrong taper, Ugh, mark3 a custom filed nylon pad made from flotsam off the beach, yes , that will do.
Posted By: Ger B

Re: alloy barrels for 750 OIF 1971 - 12/12/14 2:46 pm

Carb inlet rubber cut and fitted

Good solution to the problem, I think.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 01/03/15 10:29 am

Happy new year one and all.

The festivities are over , so its oot wi the auld and in wi the new.( Out with the old and in with the new)

The bike is out in the shed feeling sorry for itself. I have been scheming up a wiring diagram and getting shiny trinkets ready for the lord of entropy.
Several sheets of A2 and hours of scribbles later Ive come up with this ( oil pressure light and switch still to be added.

[Linked Image]
The jist of it is this.

Fused relays for main supply, ignition unit, horn, lights supply and dipping arrangement.

Existing light, horn, dipswitch and ignition switches are to use ( control) wiring at a light current , ( control supply fused by a 5 amp feed from the battery).

I plan to fit the lights , dip, and horn relays under the tank behind the headstock , cushioned by foam. The main and ignition relays are to go under the seat.
Hopefully , the lights will benefit from a more beefy supply going through decent contacts.

I plan to purchase the Japanese terminal kit from Vehicle wiring products and generally follow advice by more savvy spark masters who post on this forum. All suggestions/ criticisms welcomed.
I want to keep the flat back light and its wire stays, but this is a poor light by any standards, this will be left alone.
[Linked Image]
New repop bucket , rim and rubber instock to brighten up the front end

, but helped along by a 30 Watt 1200 lumen Cree spotlight. ( not yet purchased)

New front brake shoes. rear light lens, speedo bracket ,
wheel spindle etc
[Linked Image]

The weather here is "gash " , very wet indeed, alternating with freezing icy conditions, not good for 2 wheeled fun of any sort.

Will update when the wiring bits appear.
Here is a link to a good telly programme which covers my part of the highlands, in particular my Glen, Glen Lonan. This wont last long, enjoy while fresh. My good mate Nick Charlton is featured at one point.

Posted By: Adam M.

Re: alloy barrels for 750 OIF 1971 - 01/03/15 10:50 am

Unfortunately I got a message from the player "BBC TV programs for the UK only".
I hope your kit of terminals is going to be better quality than mine - some of the terminals were too delicate for my engine vibrations. These were aftermarket probably Chinese with separate sleeves.
With my Triumph I go all the way starting with 3 phase stator ( already bought from very good English supplier ) "-" ground and probably new very bright diode main bulbs ( mentioned in a thread on Norton forum ).
I don't know about UK but here in Canada we have lights on 24/7.
I have very good condition original loom, but will have to rework it for my application.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 01/03/15 11:24 am

I already fitted a 3 phase system a few years ago , my new loom was fitted 28years ago, it needs a refresh, there are a lot of unneeded taped up ends.
Its a pity about the link being UK only. Ive used the Japanese style crimps before and so far they have been very reliable, this is it.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/08/15 6:41 pm

Update,Its summer now, and the Beesa has awakened from its slumbers
first run with new footrests, Mk5 brake switch mount, LED 68 tailight, new rear mudguard ,
revised tappets settings and air filters.
Also fitted new / old float bowls with larger feed delivery jets, (thanks JH), I pressed them flat with 2 x 3/16" spring washers between the flanges and two long 3/16 bolts as guides, nipped them in the vice and found it took 3/4 of a rotation of the vice handle to press out most of the mount distortion, worked well no filing , no leaks so far. The new/ old bowls differed in 3 ways from the prior set, the vertical drillings exited slightly higher up the bowl, they have no drain points , and the fuel delivery orifii are about 100 % bigger, as well as sitting a little higher in the bowl so that the float level was lowered a tad, thought I would try them like that just to see if I could tell any difference.

I downsized the Main Jets from 220 to 210 because of the filters.
Reset the tappets to 4 inlet and 6 exhaust.

While the LHS foot controls were off I filed off some shabby brazing where a side stand had been fitted to the rear loop, and daubed some cellulose paint over the area , even satin was too shiny for the frame match but it will hold back the rust.

Took it for a late evening spin and wondered why the tank was rattling ( before that the first few hundred yards with soft tyres was not fun),found the strap hanging by one bolt, turned round after 6 miles and found the other bolt on the bench top / phew,refitted the strap. After ten miles more checked the mains on a long hill, no pickup up from FO with a slight roll off so not too weak. Still likes chokes for a mile or two from cold.
The intake noise is still there, I hear / see why they fitted snorkels, the tappet noise is reduced though, always a good thing.

The new footrests are good , the extra space to the gear lever is appreciated but the kick start is still in the way, more work needed, I still need to acclimatise.
Otherwise it started first kick on old fuel with not even a battery top up, I did drain about 2 pints out of the sump before even attempting to fire it up.

The handling is sublime, theres a certain bump on the entry to a fast Left hander that makes my Cagiva Raptor squirm, on the same line the beesa did not flinch, I was impressed.

The motor is freeing up well, and seems to pull cleanly through the range , maybe not quite as raspy as before. The carb needle is on its leanest setting already (.106 NJ), and the slides are 3.5 from the previous no air filter set up.
The air filter rubbers had moved a bit after the run but seem to be doing their job.

Will post pics later

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/09/15 5:17 pm

Today I rewired the headlight bucket with all new Japanese type connectors, fitted a QH lamp, and took it out again, the brake lever is at the wrong angle and needs to move down, and the carb rubbers need glued together , the section between the carb and the cut off air box partner wants to move towards the carb. Any ideas on which type of glue would join air hose rubbers back together?

Measured the head temp at about 125 C at the exhaust ports(plugs just beneath the porcelain were 120 C) and oil tank spine above engine plates at 47 C after a decent 30 mile run immediately after shutdown , but after crawling through the village at 30 mph for a mile or so.
The header pipes showed a big variation of temps, I think the chrome is affecting the laser readings, must do more research
Posted By: Ger B

Re: alloy barrels for 750 OIF 1971 - 07/10/15 3:59 am

which type of glue would join air hose rubbers back together

The same glue used to repair an inner tube?
Maybe its wise (if possible) to glue a sleeve type "thing" inside (out of sight) the hose?

laser readings,

When I teached refrigeration techniques on running equipment,
I was often more than disapointed about laser temperature
readings of those moderen instrments we absolutely needed to
be a modern training institute.
In refrigeration, five degrees off can be the difference between gas and liquid in a compressor suction line.
We went back to thermocouple fed instruments.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/10/15 9:13 am

Thanks Ger, I have some rubber cement, will try it when the weather improves ( smirr, light rain at the moment), interesting gen on the laser temperatures, so far I have only used it for measuring food temps.
Posted By: Ger B

Re: alloy barrels for 750 OIF 1971 - 07/10/15 10:24 am

interesting gen on the laser temperatures

They may have improved over time. I left the institute around 2003.
The ones we used had to be adjusted for background collour.

I still have a wire fed T-gauge which I bought for myself, and used for multiple measurement points.
Each element is a two core wire, the cores spot welded together at the end.
The spot weld - where the two different metals meet - is the measuring element.
You can hang six or seven or as many as you like around a running equipment and plug in - plug out check two at a time.

Can you borrow one from a reefer tech company or an airco installer?
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/10/15 2:15 pm

That sounds like a plan, I quite fancy watching the exhaust temps and seeing if or how they vary with carb balance, hmmm.
Posted By: Ger B

Re: alloy barrels for 750 OIF 1971 - 07/11/15 5:11 am

To have an idication of the temp of a medium inside a pipe the only trustworthy
method is to have a feeler either directly or indirectly inside the pipe.

When you have a feeler on the outsides of the pipe, the feeler is not only influenced
by the temperature of the pipe, at the contact area.
The non contact area of the feeler is surrounded by whatever is outside the pipe.
In most cases that is the ambient air.
This means that without proper care, your measurement will be a result of a lot of
outside air temperature and a little bit of exhaust pipe surface temperature.

That's not a very good reading.

So what you need to do is pull the contact point of the measuring wire strongly onto
the pipe and than thermally insulate the contact area so no outside air temp can influence
your results.

On the cooling machines I worked with (on reefer ships and later in the training institute)
that was easy. The highest temperature there was never above
80 degrC delivery gas temp (high press side) of the compressor.

A hot exhaust gas line will be really hot. You can expect 200 degrC or more.
That will be a problem for electric insulation tape, thermal insulation self adhesive tape and for the plastic insulation of the measuring wires... frown

[Linked Image]

The instrument

[Linked Image]

It holds two feelers which can be read independently.
Feelers can be:

[Linked Image]

Hand held for a quick press against surface reading, or

[Linked Image]

Clamp on as used for longer term readings.

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/11/15 6:21 am

Thats a very useful instrument, , Ive not used one of them before. I am very familiar with RTDs and Mercury in steel instruments. Given the technical challenge I shall probably pass on EGT measurement, although a simple two wire dissimilar metals probe ,one in each pipe and a differential ( centre zero,) volt meter would show with no units which pipe was hotter than the other.

Any way , back to the mundane, fluid changes coming up, and brake pedal to be adjusted.
Pistons to Deliver to JH when the weather lets up.
Currently its 100% cloud with the threat of midge attack outside.
Posted By: Ger B

Re: alloy barrels for 750 OIF 1971 - 07/11/15 6:25 am

with no units which pipe was hotter than the other

That in fact is the only thing you need to know. Absolute values in units are less important.
But be sure the feeler contact area is insulated from outside / ambient influences.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/13/15 7:46 am

Fluid changes done, some pics of previous work

Float bowl straightening, do not try this without some soft pads between the bowls and the vice, showing guide screws and spring washers between flanges.
[Linked Image]

Mark 5 brake switch mount ( works well) uses existing mount points on frame and some 1/4" alloy bar, which needed relieved where it fitted the frame. The brake switch rubber is 7 months old and has split 7/8ths already, why is Brit rubber stuff so bad?
[Linked Image]

68 tail light and new rear mudguard. Wiring in progress
[Linked Image]

Ready to go whole bike
[Linked Image]

Airfilters, new rear sets, revised footrest position, fresh paint on frame passenger loop

[Linked Image]

RHS fuel is on , paint is scabby, will refresh if the filters are a good thing.
[Linked Image]
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 07/29/15 5:24 pm

About 1,000 miles on the clock.
Air temp around 15 C, took it out for a spin at the magic hour and fed it quite a lot of beans.
Changing up from 2nd at 6K , third at 5.5 and making progress.
After around 40 miles or so , got home, nice ride, used the front brake a lot, it likes to be yanked on hard for a real stop, for setting up a corner the feel is good deep into the apex.
Air fuel mix seems good, once warm ( needs chokes for about 3 miles from cold ,no coughs or splutters).

On return took oil temp 67 C internal, 55 C oil spine.
heads 129- 130 C at the ex ports , ex pipe clamp fins 145 C. primary 85, gearbox at filler 45.

Oil light coming on at tickover/idle , suspect the quill seal has moved. I may pull the timing cases to fix the wet sumping and have a look at the quill as well.
Oil consumption very low/ negligible since last change about 150 miles ago.
A fun ride , needs a new rear brake switch and the chain is looking a bit saggy.
Gears AOK, neutral selection at standstill, nae bother.
Having fun.


Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 08/11/15 11:17 am

5 gears, four bridies and 3 fleas cemeteries. 68 Spit ( 5 speed) compared to 71 750 ( CR box)

Just back from a 250 mile round trip Argyll to Angus and back. Sunshine the whole way!
I left with about 80 miles on the Odo ,about ten miles in while overtaking at 50 ish on a right hand sweeper the bike died, put on the LHS tap ( lines cross over) and normal service was resumed. Needs both taps open at less than a half tank, topped up 18 miles later at Tyndrum. Never missed a beat after that.

The first 40 miles or so was busy with tourists,
got 12 miles of sinuous Loch Earn to myself
that was a highlight.

Crieff to Tibbermore on the back road with loads of 90 degree bends was great fun as well.
Picked up the motorway at Broxden roundabout and sat at highway speeds making progress as they say.

Visited John Hill after picking up 4 shortcrust bridies and three fleas cemeteries at Saddlers in Forfar.
John was fetlling the 5 speed 68 Spitfire when I got there.
Noted my oil tank breather had coughed some oil onto the chainguard , due to brimming the oil tank above the dip stick I hope.

Wooo , the boxes of 5 speed conversions were beautiful, the finish and all round quality most impressive, needle rollers and 21st century selector forks.. Also trick extra bearing plates.

We took the bikes out for a run, swapping round and razzing around Kirrie and Tannadice.

First impressions of Johns 68 Spit, smaller, lighter , more comfortable ( comparing to my 71).
Lower geared ( 20/ 47) , with clean selection and no funny gaps in the ratios.Revvier and noisier.

The 71 has better suspension, the front brakes are very opposite in action, the 68 feels a lot firmer, though not a whole lot stronger.

The stock riding position was weird, I am so used to rear sets now, and the up for up stock change was alien at first. My 750 definitely has more midd-range 2-4K, though top ends are similar.
The narrow nosed saddle on the 68 is great, made my bike feel like a plank when I remounted.
Pulling away on the 68 was a treat , no clutch torture and a willing motor. John's Spit seems to have a sharper sound than my motor, higher comp maybe ( no balance pipes either). I loved the side stand as well, hauling the 71 onto the center stand is hard and technically challenging on bad ground. I must get my side stand repaired, its gone the entropy way, was already knackered when I got it years ago.

John hopes to have the 5 speed boxes sorted soon, there are still some commissioning details to work out, he has just acquired a set of scrap cases to cut away so that the gear selection can be observed through the whole range, 5 th engages well on test , but when riding it wouldnt stay fully home, considering that this was a first try I was well impressed , its very nearly there, neutral and 1-4 were a very sweet clean change with no funny sounds . John reckons its just a matter of correct shimming to get the final running clearances/selection right. He is a very thorough engineer.

After a good blether and some fine scran I made my way home via a pit stop at the Cairn O Mohr winery to visit old friends. East Inch Micheal farm ( where the winery is based) was where I bought the bike in 1982 ( it was lying in a barn, an actual barn find,), the Gillies s are still there and making a fine job of the place.
The run home the next day was a neat 100 miles which the 71 motored through in 2 hours, good auld gal. Used no oil and nothing fell off. A wee petrol weep at the LHS pipe clip needed nipped up and the bike passed its MOT today with some pleasant remarks from the tester. We discussed ventilated brakes and rain scoops HO HO.

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 08/12/15 9:55 pm

Back in the real world, next run out the motor is running well then starts to pink a little between 2-3 K'

Starts running on one. Pulling on full choke restores 2 , but not happy at half throttle, idles OK. Starts Ok.

Hmm, get home and investigate. Find the LHS throttle cable adjuster has backed off and loosened about 8 mm. LHS plug is sooty. RHS plug is OK chocolate porcelain , sooty outer ring.
Adjust cable , repair a bad live connection that had poor insulation, remake the joint, the live black wire from the power control box cores are black, not good.
This may explain why the bike cut out , when I thought it was low on fuel, it had been shorting at the power box mount .

Check LHS carb mounts ( showing cracks at the adapter , hmmm ( this looks like it might be an annual service item)

Take it for a run, smoother but the miss-fire choke thing is still there, midges are too bad to investigate further.
Will check carbs and sparks later. Suspect the sooty plug isnt helping. will clean the pilots and check the needle clips are seated ok.

The LHS fuel tap is worn, I stripped and cleaned it with some fine polish but it shows a wear mark over its 90 degrees of travel, new tap needed. Its weeping from the taper cone entry hole.
Remade the LHS fuel pipe with a 90 degree elbow in copper, this prevents the pipe saying hello to the inlet rubber. Also fitted a clip to the inlet rubber, it wants to move around a lot.
The epoxy in the inlet tracts is still there , its darkened up.
Surrey cycles has brass taper cocks 1/4 each end with filter for 27 .

Apart from that everything is good, I quite fancy fitting a fly screen, and a skinnier seat would be good, the seat base is a good 2" wider at the nose than the rails of the frame.
The motor was running well before the miss-fire set in, I was amused by the yowl from the airbox between 3-4 K, this accompanied by the exhaust burble is quite a fun tune to play on and off the throttle .
The LED rear lamp stop light function failed a few hundred miles ago, its back on regular filaments again. The Qh front lamp is better than the old one , but not much.

Posted By: Adam M.

Re: alloy barrels for 750 OIF 1971 - 08/13/15 10:45 am

Damn British bikes
Always something, just to keep us on our toes smile.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 08/13/15 2:38 pm

i am hoping its just a badly fouled plug, new NGK B8es s on order and a new petcock.

Running with the LHS carb throttle cable slack probably caused the extreme fouling.

I could see a good blue spark at the RHS plug, but the LHS was in the sun, I could hear a spark, but couldnt see it, got a decent belt as a switched the ign. off on the LHS holding the plug , so I was the earth.
The replacement petcock has a quarter turn ball valve and a sintered SS filter, Ali can get them cheaper than e bay and the like , handy.
The old plugs were ancient and the good B7s I have on the shelf dont have screw on nipples so wont fit the resistor plug caps.

The symptoms are almost identical to when the HT leads were failing, OK to 3 K ( about 1/2 throttle)then breaking up.
Checked for air leaks by spraying round the carb with WD40 at tickover, no change . phew, new rubbers are spendy. I hope the current items last more than one year.
I checked the obvious stuff today, volts a plenty, charging OK. Pilots cleaned out and Needle jets checked ( one looked like it had water in it , but it made no difference)
Ali at North West MCs in Oban is getting the business , he needs it , a slow year for bikes in Argyll, I could count the good riding days this year on Two hands.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 08/25/15 4:20 pm

Today I dragged the bike out, Fitted the new LHS fuel tap with thread tape , a fibre washer backed with a steel washer and new 90 degree pipe ends both sides, this has resolved the fuel pipe /inlet rubber clearance issues.
[Linked Image]

[Linked Image]

[Linked Image]

Also fitted a pair of brand new lucas 6 volt coils and a nearly new pair of NGK B8 plugs which had been run on diesel!, cleaned these with a gas torch and a brass brush. Sparks OK and no fuel leaks, hurray.

Aided by Alex my tech assistant for the day.

[Linked Image]

Note missing clutch plug
[Linked Image]

Took it for a blast, symptoms remain, wanting choke and blubbering, in the interests of science I persisted with no choke and gave it a bigger handful on a decent hill, the bike cleared its throat and off we went, normal service resumed and pulling well , idling well, no misses.
So it looks like the sparks were OK and some internal carb blockage has sorted itself out. I am a happy chappy once more.
[Linked Image]
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 08/26/15 8:05 am

[Linked Image]

John came over on his alloy barreled 5 speed Spitfire.
Made a few other interesting notes on the differences in the early and later A65s.
Although both have similar CR, his motor sounds much sharper then mine , more staccato/ raspy,I think this is because the later exhaust system allows each pot to breath out through both silencers , the later OIF megs having more volume and baffling.
The induction "Wauh" that my OIF has is either inaudible on the 68 or its not the same at all.
The 71 750 is a lot easier to start, it runs with a battery, the 68 has a battery-less system.

The 5 speeds are well spaced, no need for clutch torture, there are still a couple of teething issues, more to do with the return spring not re-centering correctly than the actual conversion.
John has fixed a clearance issue with the cam plate so that 5th now engages fully. Getting there, the BSA gear shell is a tight space , but John is nearly there with a "plug and play " conversion.
I was able to select neutral at rest but John thinks there are still improvements to be had.
I still prefer the shorter throw reversed lever on the OIF to the original 68 gear lever with its relatively long throw, but thats a personal thing.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 08/27/15 8:09 pm

Update on the 5 speed, John found the shifter pawls retainer had been installed incorrectly. Return spring was OK.

A few more blasts up the glen on my 71 , running well, missing on one pot fault is banished,
just in time for the end of summer.
Took a run to Kilchrenan at the magic hour, 9 miles of hills and bends with no cars, just gravel on the best lines. Had a ball, the first 1.5 miles is fresh black top , and the road verges are cleared for better viz. What a playground, the bike is running great, with loads of middrange grunt, 3-5 k is the sweet spot and musical to boot. lots of hoo on the haar.
Posted By: TR6Ray

Re: alloy barrels for 750 OIF 1971 - 08/28/15 8:55 am

Sounds great, Gavin. It also sounds like you're winning your battle against entropy!

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 08/28/15 1:01 pm

Its only a small victory, the war is not over.
The BSA can be a fickle beast, it bit me hard on the leg when the mystery carb fault was playing up.
When it was being difficult to start,
wearing jeans, no boots on , I ended up with both the kicker and the RHS peg rammed up the leg of my jeans, removing skin and bursting my breeks in the process, ayah. Entropy result, torn breeks and a one inch scar plus a days worth of limping, oh how they laughed.
Posted By: TR6Ray

Re: alloy barrels for 750 OIF 1971 - 08/28/15 3:42 pm

Ouch! That's not really funny, yet at the same time . . . it is. An incident like that is hard to explain to the doctor.


p.s. I had to look up the word "breeks". This international forum always has me in the learning mode.

Breeks is the Scots term for trousers, breeches, and, as the Dictionary of the Scots Language (online) has it, also underpants.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 08/29/15 12:16 am

A wee lesson in lallans with Gaelic to follow, modern Scots being a subjugated language.

I nearly kached meh breeks. = I almost [***] myself. literally " I almost filled my pants"
As in" poch ma hone cach mhor" from the older mither tongue, " Kiss my arse you big shite"
Where Cach is the noun already illustrated, straight . Poch=kiss , ma hone = my arse , cach mhor= you big shite.

Not you TR6 ,
jist a linguistic sampler for travelers and etymologists out there.
Any way, back to the main topic.

Took the bike out for a badly timed run up the glen ,me and the bike got soaked. Only 6 hellish miles , lights worked and the motor ran Ok, speed limited by viz to 40 max, its not always a fun day. Hot shower and straight down the pub which has gone "gastro ", meaning locals are banished by London prices( 4 a pint) and nae cumfy seats unless you buy the overpriced food. Still, the crack was good.
Come the revolution!

Posted By: Ger B

Re: alloy barrels for 750 OIF 1971 - 08/29/15 5:40 am

I recognise some words which sound 'a wee' like what's used in the north of this county.

Cach = kak; Breeks = Broek...

Scientifically watertight proof the North Sea once was dry. laughing
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 08/31/15 8:32 pm

Some riding impressions now that all has settled down.
The motor starts well hot and cold. One kick after priming.
When its cold I use the Tomasseli throttle friction screw to hold it at a high idle while I get my gloves on, saves a lot of hassle. Once the motor is warm idling at a shade over 1K
When stone cold it likes full choke and a tickle, when hot nothing, no throttle either, when its sat for 20 minutes it needs a light tickle of one carb, I think the balance pipe helps a bit here.
If you forget to put the fuel on it dies when you reach 2nd gear!

It takes about 2 miles before the choke can be pulled off.
It rattles a bit when idling around 1K . 1st goes in with no percussion and the torquey motor pulls the high first pretty well. A lot of the rattling is the primary which quietens after moving off, theres some tappet noise , but more coming from the timing chest where the bushes are not as tight as they used to be.
Around the 30 limits you only need 2nd gear, on the move it pulls well hitting a surge just over 3k when a mild cammy effect comes on. Its not loud till 4K when a strong baritone blair comes on with a bit of induction roar. The motor is tolerably smooth until 5K when a distinct buzz comes from the front of the seat. between 4- 5 K its a musical instrument.
There is a hearty burble from the pipes on the overrun suggesting perhaps a wee air leak , but I cant find anything around the pipes. No backfires or other weirdness, the motor pulls very cleanly
Most of the time revving to 5K produces adequate thrust, at 3.5 K its at 60 mph and happy to waft past most things but a down change to 3rd is better for overtaking. Very torquey from 3.5 onwards with an addictive rasping rush to the delivery.
This the way its always been, the ally barrels save weight and so far the oil consumption has been very light , far better than the worn iron barrels previously fitted. I did notice a puff of smoke on start up when warm today, but it stayed clear after that, first time Ive noticed.
Motor oil is silkolene straight 40, ATF in the primary, Hypoid 90W gear oil. Fuel, Esso super unleaded is best, but runs OK on the cheaper stuff.
The LHS footrest acts as a rear chain wear indicator , a distinct knocking can be felt here when the chain gets too slack.
Im very pleased with the revised footrest position,at 65 or so the wind balances the upper body weight and it feels roomy on board, , nothing has scraped yet, although I fear the RHS will be down first. I am considering fitting a flyscreen of sorts to keep the rain off my knacks.
The chain is, as was fitted when excavated from the shed, it isnt the best cosmetically but its holding out Ok with a squirt from a can when still warm after a run.

The 30 mm carbs work very well up to about 5.5 K in top after that I feel its running out of breath a bit, however thats about 90 so in the interests of ride- ability Im happy, the sound and fury of 6-7 K is only for special occasions! The gearing feels good, occasionally I still try looking for another gear.
Considering the lazy fork rake the bike is surprisingly nimble and feels light on the move, just look where you want to go and your there.
The back brake works OK, not so fierce that it wants to lock, I have a gravel section to deal with at the end of my road and its very useful there. The front is just poor compared to a disc, it works , it has an amusing name , and a novelty rain scoop. Perhaps it would be improved by an hydraulic operation, but then why not fit a disc.

I have an MZ 250 front end in the shed, it has a 10 inch disc and a Brembo pattern caliper. also has an 18 inch alloy rim and I think Paoli copy forks, my only concern here is that the wheel bearing are smaller than the BSAs.
This should also be lighter. hmmm
The MZ fork tubes are a shade thicker than the BSAs and the fork centres are similar, however, the MZ steering stem is a lot longer, and so are the fork tubes/springs, so a bit of machining will be needed.
Fitting this would make the bike a good bit more rideable, emergency stops are quite common on the single track roads around here. First I need a lathe, and before that I need a place to put it, so this isnt happening just now.

Road holding and handling are very secure, the late forks do a reasonable job of dealing with the crap roads and work very well until the front brake is used, the forks are not well braced. But its OK, almost anti dive, ha! Nothing much upsets it , no head shakes, and the big 19" front wheel rides easy over small bumps., the seat is like a plank, firm, not too bad over a long distance, but its a bit wider at the front than the dry frame seat and they feel better, I may do something about this.
I have a 5 gallon ally tank in the attic that used to be fitted , will dig it out, its cracked (of course) right around the rear seams, Its been repaired before ,I mentioned this to a local welder and he was game to try for a 2nd repair, I think it might survive if the bracing is improved ( there isnt any). It looked the bollox back in the day. Polishing it got a bit lame though.
I plan to have 2 tapped bosses welded to the front pannier section and attach a brace to prevent flexing, originally it had hooks for bungees, fat chance.
This also needs a strap mounting of a permanent style, again it was just bungees looped round the frame ( and gravity) that held it on.

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 09/02/15 8:09 am

Pics of the Alloy tank.

[Linked Image]

The current fuel tap location wont work.

[Linked Image]

[Linked Image]

Tools for carb synch time,
[Linked Image]
Top spanners for throttle cable adjusters.

Spark plug spanner.

Screwdriver for carb screws

&mm socket for worm drive clips.

The spark plug spanner doubles as a clutch screw adjuster, I ve had this tool since I got my first BSA aged 17, its a Melco ,it goes everywhere and lives with the ringer and allen keys in the bag.
I filed the end up for clutch screws and have used it since then .

Because I now have air filters in the way to prevent decent access to the slides, I used this device to balance the carbs.It plumbs into the balance pipes , I made an extra piece of balance pipes, so that for the first part of the synch job the manifolds were isolated from each other.
[Linked Image]

Between the HT and the rocker feed you see the blanked off balance pipes and the clear tubes to the meter have been run under the tank in readiness.

[Linked Image]

The balance meter can hang from the bars when riding, I take it with me this way , and do the final balance set up in the middle of nowhere so as not to piss off the neighbours.

Set off up the glen on a nice breeze from the west. 6 miles up after lots of 2nd gear stuff the bike was warmed up. Riding with the inlet balance pipe blanked wasnt too bad , no issues.
Parked up and set each cylinder idle mixtures at the pilot screw individually, , plug out, opposite, repeat visa versa, .
This was done at a high idle set on the throttle friction screw, around 1500.
Both cylinders needed a slight enrichening , and picked up 100 rpm or so from the as found settings.

Connected the balance meter, and prepped the LHS throttle cable for adjustment ( this had come slack previously and was suspect)

Kicked it up and adjusted the LHS throttle cable till the lower ball ( which shows induction bias between the manifolds) remained beneath the upper ball when the throttle was blipped.
Very easy to use.

Discod the meter , reinstated the balance pipe and rode off into the sunset.

The prep for this takes about an hour, the tweaking less than 5 minutes.

When reconnected the idle was too high, dropped each side throttle stop about 1/8 th of a turn. The clack as the slides drop from a twisted throttle is clean, no clich clack.
Most of the overrun burble has gone now , and the motr has smoothed out a bit.

Checked the mileage, 54 mpg at the last fill, that had been mixed riding, lots of low gear B road, mixed with faster A road blasts. pretty good I think. Oil consumption , nil since 250 miles at the last change.

The alloy tank has cracks and repairs .,I will take it to the smiddy and see what the ace welders can do.
[Linked Image]

These flat tabs will be replaced with round bosses tapped 3/8th UNC for a tank brace to prevent further cracking.
The fuel take offs will be relocated to the lower pannier section of the tanks to get out of the carbs way.
[Linked Image]

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 09/06/15 5:37 pm

Comments on the tank invited, if you know who made it ( probably in the UK) then I am interested.
It was fitted when I bought the bike in 1981, it was split at the front the time, I had it repaired and the splits re appeared at the rear. It may be a hopeless cause. Opinions from alloy welders welcomed.
Posted By: Zombie

Re: alloy barrels for 750 OIF 1971 - 09/06/15 8:28 pm

Generally speaking a weld will outlast the original material. You will often times see cracks develop alongside the weld but not often thru the weld.

There are two potential reasons that I know of, and they are actually related as one. It gets pretty intense mathematically but put simply... Heat expansion during the welding process expands the metal. Everyone knows this. Distortion occurs, and amplifies as the material cools. A large amount of stress is imparted in the cooled part.
The only way to release this stress is to anneal the entire tank/part in an oven at reducing temps. for several hours/overnight.

This was obviously never done in the case of your tank, and the incorrect alloy was chosen to begin with. Also the filler material must be softer than the base alloy or the cracks would not run thru them so easily.

Look at your tanks original welds for a pattern weld. Was it one continuous run or was it several small runs "stitched" together? This is only a clue as to the knowledge of the fabricator.

If you really wish to repair, and use that tank, I would start with annealing it properly. A rosebud torch, sooty flame, and time. Follow that up with 2-3 hours in a 500 degree oven, and lower the temp by 100 every 1.5 hours until you are at 100 degrees F.

All of this is AFTER you repair the current cracks but while still hot from the welding process.

The whole issue I believe is just the wrong alloy for such a project.
Posted By: Triless

Re: alloy barrels for 750 OIF 1971 - 09/06/15 9:14 pm

Gavin, I would be very interested in your views and methods if you go ahead with the MZ fork conversion. Nice lateral thinking that!
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 09/07/15 8:07 am

Thanks for the comments,
the first set of tank repairs near the front , lasted OK , the tank was annealed after that, the new cracks run across the origial construction welds. I have a new plan, taking the tank to JH who has contacts with Ramsay ladders in Forfar, they are masters in Al fabrication and also have annealing facilities.
The plan is too fit two 1"diameter round bosses near the front fitted with 5/16" threads to take two studs, at the rear the old fuel cock mounting will ne used yo provide a rear brace.

ive thought long and hard about the MZ conversion
I also have a few bits ( sliders , wheel and disc ) for a later T140 style.
MZ pros, probably lighter all round, brembo brake 10" disc, forks similar diameter and centre width.
Options , modify the 71 yokes to take the MZ legs, this would mean shortening the MZ stanchions and springs and tapering the tube tops and threading.
Or fitting a whole MZ front end with a modified steering stem, the MZ steering stem is longer
Cons, , not many, custom tube and spring work, smaller wheel bearings, non std look.
Loosing the rubber mounted handlebars ( quite a big deal for me)

T140 pros, with the correct yokes/ triple trees, its a bolt on, looks stock, no machining needed.

I would still need lamp mounts, yokes , a caliper and fender brackets , heavy
Posted By: Adam M.

Re: alloy barrels for 750 OIF 1971 - 09/07/15 9:23 am

+1 for the complete MZ front end with only modification being steering stem.
I don't thing smaller wheel bearings make any difference.
And they are easy to renew and cheap.
You can always came back to stock.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 09/14/15 12:06 pm

The problem with the complete MZ steering head is that the MZ bars are solid, I like the rubber mounted bars on the BSA, however the fork centres are so close I think its possible to shorten the MZ stanchions, damper rods and have them machined to suit the BSA top yoke.

Back to real life.
Lately I have been mostly enjoying the bike and messing with the brake pedal height.
This now has a more pronounced lean down and suits the riders geometry better, I had to make a distance piece for the switch striker, used two bits of 1/4" Nebar gasket material.

Also fitted an oil tank breather extension. The old breather used to end just above the gearbox sprocket, because I brimmed the oil tank it was spitting a fair bit of oil out, this has been extended to as far aft as possible with a bit of garden house. RAF , but you can only pee with the cock you have. Will tidy this up later. The weather here is fine at the mo and I want to ride not wrench. Prior incarnation with the old barrels, the oil would have been used up by now. But it hasnt burned any since the last oil change. Plus points for the new barrels and good ring seating I suppose.

The carb balance is now very good, did a spark plug chop on a quiet night at the magic hour.
The Mains are a tad rich, currently fitted with 210s.
This is interesting, when I first got the bike , no air filters, two into one siamese with short reverse cone mega, 210s were too lean. The pipes didnt seal well at the head and I think this helped to spoil the readings. It ran on 220s for years after that.
Now with good tight bores, well fitted stock pipes and the air filters in place it is rich.
I have ordered 200s and 190s for further trials.
last fill was regular unleaded, not noticing any difference.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 09/14/15 8:27 pm

Some thoughts on the longevity of stuff, heres a rough list of whats been worn out / or not over the years.
Its a dull sad read, I have left out rubber because it is so ephemeral. And nuts and bots, renewed whenever possible.

When i got the bike in 1981 it was a barn find, all there , an alloy tanked cafe racer beast, with a box of spares, it had been previously fitted with the full Devimead go over, end fed , big bore (750) , but it was rough. Relocated side stand, broken original side stand, leaking unfixed tank , leaking motor, no functioning kickstart, wrecked clutch , close ratio 1,2,3 ( unusable).
rear sets ,ally mudguard ( fecked), seat tied on with wire.

I still remember the buzz when it came back to life after a new battery and clutch fix.
It was like a new instrument.

These are the entropy casualties
When I use numero 2 I mean the part has been replaced once. C = crash, V =Vibration loss

Since then .

Frame , welded at oil tank to rear motor mounts ( caused by seized swinging arm bearings)
Swing arm bearings 2 ( no nipples found or used originally)
Rear fender 4 4V
Rear light 4 1c 1V
Seats 2
Front fender 3 1V
Tank 2 1V
Bars 3 1c
Clutch lever 2 c
RHS switch cluster 2c
Tacho 2c
RHS pegs 3 , 1 vandalism ( left down when kicking with a 15 stone ( 15 x 14 lbs ) wood beast.
LHS pegs 3
kick start rubbers , bought a box
Gearlever rubbers , ditto

Pipes, 4 . 1 c
Cans, 6 2C

Chains 5
Gearbox sprockets 3
Rear sprocket 2
Carbs 3 ( still got the original tops), 6 slides, 6 NJs , 2 Springs

Motor stuff
Spark plugs 3 NGK for last 2 after N3 Gs
Rocker spindles 2 , they were cheap at C and D autos so I thought , why not, made no difference at all.
Inlet rockers 2
Valves , 3rd set
Guides , 3 exhaust set
Springs, 3rd set
Pistons 3rd set, rings , 4 or 5 (no air filters)
Barrels 2 the iron "jumbos " from devimead were good but wore out from no air filtration.

Con rods 2 , the old ones were polished beautifully, but I changed them for a better weight matched pair of 1970s with the original peened finish.

Crank, 1 big end regrind, to -10, DS journal was oval. 2001

Shells, 2 sets.
Cams 2 original followers refaced, DS outer lobe worn
Oil pump, number 2, I bought a used 71 and freshened it up, to replace the old iron unit., 2001

Drive side
Primary chain 2
Front drive sprocket 2
Clutch pates 3 sets
Steels , 2
Hubs 2
Drums 2
Cush drive 2
Springs 2
Push rod 2
Rollers 3 ( waste of time)

main bearing 2
swapped 3rd gears ( not for wear reasons)
Sleeve gear bush (top) 2
Selector forks, 2 ( selective assembly from a handful)
Cam plate and plunger 2
Kick start springs 4
Still got the original gear change return spring
Pawls and springs 2

Air box outers 3

Oil pipes 2
Fuel pipes, lost count

Fuel taps 3 1/2

Coils, 3

Ignition 4 points, rita, boyer ( 2nd boyer)

Alternator 2
Batteries,bulbs lost count.
Loom 2 ( 3 really , the original was long gone when I got it)
Headlight 2

Wire stays 2

Fork stanchions 3
F brake shoes 3
Shocks 3

throttle cables , more than 5
Clutch cables ,3 ( the last one has lasted 20 years, thanks SRM, shameless plug for good stuff that doesnt spoil your day)
Front brake cables 2
Speedo cables 3 C
Tacho cables 2 C
Realistically not all of these items had worn out , some were functional but dubious or scabby.
I was sad when the original alternator gave up, the rotor got tired and the stator cooked slowly.
Its a shame to lose magnetism, maybe it goes back to another dimension.

Still original as I got it. Whats left of this 1971 A65 is below.
Ive crashed it twice bending fork stanchions each time,interestingly it wasnt the front brakes fault, pilot error each time.

Bearing in mind 2 sets of bent stanchions,
Borrani flanged alloy rims, strong and light , still straight !.

Rear wheel complete, nothing apart from the sprocket is worn.( OK, 2 broken spokes )
The paint is [***] but it all works.
. Yokes, steering head bearings ( amazing), sliders and end caps ( no torque wrench !) Frame has a broken Side Stand mount and messed up tank mount U bracket.
Front wheel, rim, spokes, drum,bearings 3
Air box inner and battery mount.
Kick lever
Gear shift lever.
Oil tank cap and dip stick.

motor cases (all ), main bearings , timing gears, bushes, OPRV, oil switch.
Cylinder head ( repaired , re guided, but hanging in ( the seats are still good)
Crank ( bar a regrind).
Header fins .
Gears, all needle rollers and gears are as fitted bar the 3rd pair ( was a CR 123 when I got it)
The CR3 is way to close to 4th and is nearly useless for the roads around here.
The main shaft TS bearing was changed as a precaution.

Zener diode still works but is redundant

LHS switch cluster
Tomasselli twistgrip
One speedo mount
Side panels

Its been a lesson in wearing stuff out, if you ride your bike stuff wears out, to keep the parts coming , ride your bike.
nowadays theres some great stuff out there to keep your old bike going, its never been better.

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 09/17/15 5:45 pm

Chatting about the front brake at the LBS , Blod reckons its worth sticking with the original set up but with a hub concentricity check and a set of new shoes custom thickness from Saftek in the UK.

The brake is not that bad, pleasant to use at low speeds without being grabby or pulsing, but from higher speed it lacks power. I will try this as a least messing around option, the front end is coming off this winter to get new stanchions , the old ones have about 90 percent chrome between the yokes and look scabby.( 55 quid from Ali at North West Motorcycles.) and a new wheel spindle ( in the shed), plus a check of the steering head , yokes repaint etc.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 09/18/15 6:33 am

Saftek replied,
34 all in including post and VAT to reline old shoes with Premium grade 3915
Sounds like a deal, they have a good rep.
Old shoes from the entropy bin going in the post today.
Posted By: TR6Ray

Re: alloy barrels for 750 OIF 1971 - 09/18/15 10:39 am

Originally Posted by gavin eisler
Some thoughts on the longevity of stuff, heres a rough list of whats been worn out / or not over the years. Its a dull sad read . . .
Not at all dull or sad, in my opinion. I enjoy reading about your lengthy relationship with this bike and your years-long battle against entropy.

Originally Posted by gavin eisler
I still remember the buzz when it came back to life after a new battery and clutch fix. It was like a new instrument.
That has to be experienced to be understood -- it is what this board on the forum is all about. I imagine that most people who seek out and read these threads have experienced what you are describing, or they aspire to do so.

Originally Posted by gavin eisler
Its a shame to lose magnetism, maybe it goes back to another dimension.
A classic statement for sure. You have a way with words. Keep it up, Gavin. It's a good read.

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 09/20/15 12:47 am

Thanks for the kind words Ray.

The Entropy pile would look like this , a load of rubber, perished , worn, burnt and rotten.
Mangled, bent steel and stinking, burned alloy, with some faintly worn parts.
Hovering on a lake of burst oil in a miasma of burned hydrocarbons.
In a void cleared by a strange rasping roaring sound.
But , thats life as we know it.
Its great to be riding this machine again, its very easy to ride, apart from the high first, its super forgiving, and so rewarding, modern rubber and a good road with a raspy twin, sonic joy.
Kids and old folks love it as well.
At idle you hear the primary chain slap, some cam gear slop and tappets,( not unlike a Ducati bag of spammers sound) once moving this disappears and the pipes come in to play with the air box.

It is slow , my Cagiva 650 Raptor beats it by 112 to 95 on the acceleration test at a local straight . But the beesa is easy to ride without having to tap dance the gear lever.A big part of this is the heavy flywheel, the initial launch as the clutch feeds in on a higher gear robbing that inertia , its a sensation modern bike owners will never get. The roadholding and stability are superb, modern bikes are no better, the only better handling bike Ive had was an Ariel Arrow with pressed steel frame and leading link forks!
Posted By: Triless

Re: alloy barrels for 750 OIF 1971 - 09/20/15 5:51 am

Yes, Ray is right, a nice way with words and a good read! Bit unfair comparing with the Cagiva, though, Different epochs!
Bit off topic, but would love to read of your experience with the Ariel, though.
George Brown achieved amazing things with his sprint version.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 09/20/15 9:57 am

I suppose I can Hi Jack my own thread.

The Arrow was BSAs ( well, Ariel by name only) best moment IMO, it cost the factory a fortune to retool for. This was forward thinking for the future, a brave new world of monocoque chassis , leading link forks low C o G. Its a shame the buying public couldnt see past the styling for what it really was.
It was and still is a bike for the future.
Fuel cell mounted low under the rider seat for mass concentration, a huge stiff beam frame with storage in the dummy tank, forks that didnt twist or dive when braking.
Excellent sprung to un-sprung mass ratio.
I found the Arrow to be extremely stable, still remember being on the back of my mates arrow when he set the throttle, put both hands in the air and his feet out the front sitting on the tank, ridden like this along the Kingsway at dead of night taking the roundabouts with pillion input alone.
On a separate occasion, I hit a house brick at full lean on the inner apex of a 90 degree bend.
It didnt deviate from its line ( it did break one of the alloy links in the fork , but no skin was lost).

My Arrow had been through several hands, I flowed the transfer ports , raised the exhaust port an 1/8th" , cut the windows out of the piston transfers, fitted skimmed heads and a big 389 carb, the motor flew ( used a lot of fuel though ).
The stock 20 HP motor was tune-able with around file and a hacksaw, free HP for any fiddling teenager. The down side was a bike that would do less than 30 mpg if you used the motor hard. Mine would gulp fuel to the point the fuel cell breather wouldnt cope , fistfuls of throttle meant bouncing up and down on the seat to stop the fuel tank air locking!
The front brake was a big twin leader from a Suzuki , both rims were 18" alloy Borranis.
My bike wore Avon GPs.
The cow catcher front mudguard was long gone, just a short alloy blade at the front and back.
Ace bars and a green silver paint job.
I changed the main bearings without taking the motor from the frame , how cool is that!

With a disc on the front , 5 or 6 speeds and a reed or disc valve on the induction it would have given the Japanese two strokes a run for its money and left them for dead at the end of a twisty road.. The bore and stroke was the same as a TZ 250, look what they achieved!
The big negatives of the stock bike were a pathetic front brake, and unfashionable styling, the 16" wheels were too far ahead of the time and tyre choices were limited, no TT100s or race tyres would fit without changing rim sizes.

The 4 speed box left awkward gaps in the acceleration game.
I sold mine when I moved from my folks into town, as an apprentice getting my own pad used up all my funds, so it went.
I wish I still had it.
Although popular here in the UK as a learner legal bike, I understand the export across the pond was not paying the way, a step too far for dyed in the wool 4stroke fans, the Dan Dare meets scooter styling putting many off as well.
BSA canned the Arrow in 1965 , after a 5 year run, to concentrate on the push rod unit singles, the rest is history.

Posted By: triton thrasher

Re: alloy barrels for 750 OIF 1971 - 09/20/15 10:18 am

High mileage and alloy petrol tanks means cracks, in my experience.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 09/20/15 10:55 am

I agree TT, the alloy tank looks good but I am happy to stop at 110 miles or so to refill, the extra capacity isnt much help.It will probably go well down the list of things to do.

Top of the list is a better front brake.
Closely followed by frame repairs , a side stand would be handy and the fuel tank mounting bracket is toast , that needs welding as well. Frame outage planned for the winter, probably a repaint as well. Cosmetically the frame paint is well past it, frame and air boxes need tarting up.
The handle bars are under review as well, I want something similar but the adjustables dont work with the clocks in the "Ace" position, its very comfortable as is . But simpler bars would be better/lighter.
Posted By: Triless

Re: alloy barrels for 750 OIF 1971 - 09/20/15 5:58 pm

Great Ariel story, Gavin. Thanks for posting.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 09/21/15 6:41 pm

The last run , round Loch Avich and up Loch Awe side, 50 miles of extreme roller coaster single track and gravel, brought up an old issue, heavy braking , down hill on poor surfaces, bumpy not loose, brings out extreme fork twist, you can feel a squirm as it all bottoms down, so any braking improvement means a stiffer front end as well.
Anything would be better than the OEM rubber mounted front mudguard.
Given that the front brake is not brilliant, fork twist can only get worse if this is upgraded.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 09/22/15 8:30 am

Some recent pics, I found the camera cable at last.
Mk VII brake pedal, last mod , angle revised and cork striker/packer for switch. I may delete the pedal arrester hook, it is a bit flimsy, a small scallop from the top of the pedal to locate against the upper hevx screw will be better and less prone to moving, the hook wants to unscrew under lever pressure.
[Linked Image]

Temporary RAF garden hose breather extension, now replaced with a tidier complete hose.
[Linked Image]

After a 50 mile run in the wet round Lochs Nell, Feochain, Avich, Awe and Tromlee, the bike can make cockerels hover
[Linked Image]

Showing the Tomasselli twist grip and useful friction screw ( vertically down ), the knee scratcher throttle stop is a useful danger feature.
[Linked Image]
Top side
[Linked Image]

The adjustable ace bars conundrum, not enough space for clocks and cables when lowered into the "making progress" position.
[Linked Image]

Rear view, grey face tach , and repop blackface speedo, plus LHS pillion footrest down to annoy people who crave symmetry, wrong back light for the purists.
[Linked Image]

Strangely clean looking
[Linked Image]
Up the Glen
[Linked Image]
[Linked Image]
[Linked Image]
Looks better off the stand with the front settled
[Linked Image]

Posted By: kurt fischer

Re: alloy barrels for 750 OIF 1971 - 09/22/15 9:58 am

Thanks for the pics, Gavin, you are giving me ideas for my '71 A65L, I might even get it back together some day!
Posted By: JER.Hill

Re: alloy barrels for 750 OIF 1971 - 09/22/15 1:42 pm

Hi Gavin

Like the idea of the green house workshop, might need to shuck my thermal coveralls in there.

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 09/22/15 4:22 pm

Hi Kurt.
Glad to inspire, some points I am happy with, some room for improvement , some thing never change.

Good deviations from stock so far.
Chassis, rear sets are great, the mount plates should really be thicker 8 or 10 mm, ( 5/16 or 3/8). They take my weight OK, but one kick with the peg down put a twist in the RHS , this torqued back out , but it should be stiffer. The riding position is good for comfort, takes the kink out of my knees and the adjustable bars sit a couple of inches forward from stock, lovely on the go, no neck pain in town.
Alloy rims, yum yum, but they are a pain to clean, the flanges are strong though, no arguing with a straight wheel after two sets of bent forks!
Later triumph tank,good range, bolts right on, the 71 tank is not a thing of great beauty IMO, if you keep the stock carb mounts its hassle free. The later T140 peanut also fits ,looks good, but with it fitted you can pass anything on the road but a gas station.
68 rear light, saves weight , doesnt offend the eye like the " Gargoyle", needs a bare fender to start though. I used a T140 bare SS, this was cheap-ish , and quite a bit lighter than the stock fender.
Brake arms . extended alloy, better than stock, feel is improved if anything, it doesnt turn it into a disc though, I wouldnt go back to stock, but at nearly 100 they were spendy.


End fed crank ( Devimead 1970s vintage , still on original mains), a huge boost for moralle and confidence. The quality remains long after the price has been forgotten.

Barrels, 750 Alloy Nickasil , Made in Scotland, well mostly. Great , same zip as the old iron ones, more mid-range .Pulls the 21/ 47 with ease , I still try for another gear at times.
Oil consumption almost nil at 1,800 miles. Reduced tappet clearance means a little less noise from the top end. The 750 pistons are lighter than stock BSA 650 so there is no major increase in vibration.
Lightened timing gear, not worth the bother, may even be a bad thing. However they are staing in.

Transmission, Devimead/ SRM clutch pressure plate with needle roller thrust plate, great stuff , I can sit with the clutch pulled in traffic with no creep, engage neutral at rest as well, when cold 1st is silent, once warm there is a bit of a clunk but not significant. The rest of the clutch is fresh, Surflex plates and new steels. Not heavy to operate either.
Primary chain stock triplex. ( this is noisy put fairly reliable), a belt would save weight, one day)

Gears, raised 1,st and 2nd . stock 3rd and 4th. Great on the move, no gaps once rolling, in town 1st and 2nd is all you need, if you stay in 1st traffic gets out of the way, its very intimidating, quite a good safety feature. Will roll at 30 in 3rd if you need to be quiet.
This is much more fun than the stock set up with the hole between 2nd and 3rd.
Downside, its a 5 speed box with no 1st!, the motor can cope because of the easy low rev manners, but the clutch gets a hard time. My fresh clutch has no issues , but the old worn one had all the vices.
Gear change, one up 3 down, its great, the reversed lever and CR box has a very different feel from stock, shorter and slicker. Accelerating with a press down for up is a real pleasure.

3 phase alternator , with new rotor.
Generic reg/rec, finned sort.
Boyer red box with 6V Lucas coils, copper leads and NGK B8s, totally trouble free ( after replacing the leads ), the NGKs were effectively out of a bin, the LBS had pulled them from a Z1 that had been filled with diesel, cleaned up great.

the remote attachment causes so many space conflicts ,really its too tight a squeeze. It is handy for maintenance, but the stock air box wont line up without surgery to the rubbers, and the flange adaptor rubbers have a fairly short life, maybe 2 seasons. The carbs wont froth and the longer tract is theoretically a "good thing ", but, I probably wouldnt bother again. The carbs droop on the rubbers after a year giving a down at heel look I dont like.

Throttle cables , the mountain bike rear brake noodle to swoop the cable into the top of the carb is great, cheap easy, feels brilliant, light and snappy throttle action, the single best thing you can do for almost free when fitting new cables. They should last a lot longer as well, that bend at the top of the carb always splits the cable outer first.

Tomasseli twist grip, two cables all the way, less prone to failure than the over-strained one into two stock set up, easier to balance as well, adjusters in the open , not under the tank.

Stock stuff I would still like to change,

The seat pan, narrower at the front, would be an improvement.Lowered an inch would be good to.
I am 5' 10" , any shorter and I would struggle.
The seat catch, its fully Mickey Mouse , I detest it.
Centre stand, could be an inch shorter, handy for rough ground but a bit of an extra heave.

Side stand is missing, it would be handy.
Front brake, a disc may follow if new linings dont help. I will try this first though.
The rain scoop effect is very unpleasant.

Forks need braced. The later T140 with disc has a better bracing arrangement, one day hmmm.
This could get spendy though, needing new triple trees/ yokes, lamp brackets, fender , fender mounts , wheel , disc caliper etc.
Speedo/ tach brackets, pressed steel tack, yeuch.

Good stock stuff.
Frame and forks, still very good on modern roads, confident handling stable but also chuckable.
I like the look of the wire stays lamp brackets, and the flatback lamp. The tragedy is that the flat back does not have enough room for an improved reflector like a Cibie.

Most of the running gear is sound, well thought out and conveniently available because so many parts were shared with Triumph, a big bonus when it comes to buying spares.
A lot of stuff that is solid on the dry frames is rubber mounted on the OIF, this helps component life. Side panels dont wear out, electrics are given an easier time, no squeezed coils.
Wheel sizes are not too weird and half decent rubber is out there.

Headers and cans.
After trying 3 sets of 2 into ones, LC style, Dunstall, Armours I am happy to fit the stock pipes, it runs best like this and doesnt leak either. All my 2 into 1s were hard to keep sealed, the immense back pressure likes to get out somehow. The balance pipe effectively doubles the silencing and outlet volume , its a good thing. Its got the best sonic possibilities. You know its not a 650
as soon as it starts , there is a basso profundo element the 650 is lacking, up to 2k it just sounds fruity, 2- 3 K introduces an element of menace and clears most traffic, 3-4 K a snarl develops that means the dawdler in front gets right out of your way with a worried look, 4-5 K, now the gates of Hell are open and a rasping tearing noise fills the air, animals flee the road and hide at field margins, children start to cry.
Leaving it in first in town and using 3K to stay at 30 mph is like having a blue light and siren on.
On the other hand I can creep home in the dark using higher gears without causing too much disturbance, a good compromise I think.

Oil , Silkolene Chatworth Straight 40, " Speed , Silence , Satisfaction ", two out of 3 isnt bad, the motor has had this for the past 15 years, before the crank was reground I used 50W.
Its probably a bit more clattery with 40, but it runs very well, no piston scuffing whatsoever on the old iron barrels , you dont see many old A65 pistons like that. I think 20 /50 is overrated.
No oil consumption / burning since the new barrels were fitted.

Enough talk.
Now , Tonight I have been mostly testing main Jets.
Timing water though different jets ( amal 200s , Wassel 200s, Wassel 190s) before I change the current 210s for a leaner pair.
Set up a funnel on a stand with a 6 foot hose to the test jet. Timed a funnel full for each jet with the second hand on the clock.
Results were interesting , some tests were repeated due to funnel spillage and air locks.
The Amals 200 and the Wassel 200s were within a second or 2 of each other, withing experimental error margins. The 190s were definitely smaller, giving approx 10 secs longer to drain, 50 ish versus 40 ish.
The worn looking Amal 200 flowed the same as the good looking one, so presumably the damage is just cosmetic.
All jets produced a satisfying water pistol jet with no strange flows.
Most amusing , harmless fun.
Going leaner with the new Wassel 200s tomorrow, more testing Yay!.

Posted By: Allan Gill

Re: alloy barrels for 750 OIF 1971 - 09/22/15 4:42 pm

It's not just the hole in the jet which controls it's metering but the counterbored drilling at the bottom effects also. You will notice that they are not always identical
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 09/22/15 5:48 pm

I suppose for an accurate test of this I would need to reverse the flow through the jet, in the first tests I screwed the jets into the plastic hose so the flow was from top to bottom , opposite to real life. The problem is , how to seal the hex jet end to the round pipe for a real life direction test. Any ideas welcomed.
My main concern was that the wassel 200s were close to/equal the Amals, I had it at the back of my mind that they were one jet size out, so I decided to find out, now I am happy that a Wassel 200 flows the same as an Amal 200. I didnt want to fit something oversize that was the same as the current 210s, or way leaner if they were undersize.
Up till now I always bought Amal stuff from SRM to be consistent, now, however there is a new LBS in town, Ali who runs it is a good guy, but he trades through Wassel, I want to support him , so I am reluctantly trying some of their stuff out. Years ago Wassel was not good, cheap but , shoddy. Ali finds they are often stockless nowadays, so not that handy.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 09/23/15 2:35 pm

Fitted the Wassel 200s ,took a run intae toon, 12 miles, pissing down for 4 , nae Stornoway Black Pudding at the Bay view , thats 2 days now, not pleased.
On the way home stopped at main jet hill, waited for a gap in the traffic, flat out in all gears to 3, killed the throttle and did another plug reading, still a tad rich, the earth electrode is grey at the tip , black at the root, the thread ring is black too. No drop in performance , smoother if anything, 190s going in tomorrow.
Dug out the old seat cover top , foam and base, this is more sculpted at the front , with a taper to the top instead of the slab thats fitted, also found some old swept backs that may get a 2nd life .
A job for the Singer , yay.

Posted By: kurt fischer

Re: alloy barrels for 750 OIF 1971 - 09/24/15 8:20 am

Gavin, thanks for the write-up on your bike -- wow -- I've got lots of room for improvement!
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 09/25/15 7:07 am

More on the seat, I dug out the old seat pan , foam and whats left of the cover, the old pan is 7" across the nose, the current re-pop is 9".
[Linked Image][Linked Image][Linked Image]
The old foam has some sort of rubber cancer and is crumbling away, the seat cover is also hard.
Called RK leightons to discuss, they are happy to blast , repaint and recover the old seat pan.Fitting later foam and using the old top as a pattern.What a great shop , the proprietor knows his seats, turns out my re-pop slab is dimension-ally correct for the period,the seat nose matching the tank width. Later Triumphs got the narrower pan, tho mine must be from the period they still had RHS hinges.
They can also refit the missing catch hook, which they have in stock.
I posted off the old base and cover .
Anyway, looking forward to a little more comfort and style in the future.
It pissed down yesterday all day, MJ tests later today hopefully.

New clutch actuator parts from British only with the juicy bill ($73.22 to the door!) and OTT packaging, custom neoprene printed baggies anyone., postage was a reasonable 10.
[Linked Image]

New Wassel on right, old Amal on left , note smaller drilling on Wassel
[Linked Image][Linked Image][Linked Image]

Jet intake sides, new wassel on left is similar to one of the newer Amals on the RHS , old Amal in middle
[Linked Image]

Srangely worn and abused Amal 200 on right, Wassel 190 beside it, the Amal flowed OK in the water test , but I didnt like the look of it.
[Linked Image]

A fistful of MJs , Wassel on left assorted Amals on RHS
[Linked Image]
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 09/25/15 1:27 pm

Work before MJ tests,
Off with the TS cover, showing end feed mod and boyer
[Linked Image]
[Linked Image]

Old and new actuators, the fixed plate, greasy no balls , is the worst worn, new below
[Linked Image]

6 CA breaker plate with no AR, and extra bearing, on it when I got it. Just as an aside
[Linked Image]
Showing Oldham coupling and bearing housing
[Linked Image]

Potential breather catch bottle
[Linked Image]

Copacetic harmony, tweaked kicker outwards in the vice, no longer clangs off header pipe.
[Linked Image]
MZ 250 H bars, neater, slightly less forward lean, no instrument issues, triple plated!, needed straightening in the vice first. Comfortable.
[Linked Image]
[Linked Image]

On plug chop hill, cooling down
[Linked Image]
[Linked Image]

RHS plug , MJ 190 reading
[Linked Image][Linked Image]

LHS plug MJ 190 reading
[Linked Image]
Picked up all this litter while I waited for it to cool down, found evidence of oil change, bottles galore, and a washing machine drum!
[Linked Image].

Posting plug readings in Motor cyclwe general for opinions.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 09/25/15 2:03 pm

Clutch click begone, the actuator parts have created a $72 silence, hurray.
Fuel economy has risen, bearing in mind Main jet testing and lots of 2nd gear jaunts up the glen.

"Your real-world MPG average is 66.07, covering 160 miles using 2.42 gallons of fuel.",
thats with the 200 MJs, now with 190s should get better still.
Posted By: Allan Gill

Re: alloy barrels for 750 OIF 1971 - 09/25/15 2:47 pm

Nice work Gavin. If your cam and head is stock then the jetting shouldn't be much different than standard ( at the main jet at least) spitfires and I think A70's had the same main jet size as lightnings. So trying a jet smaller still could be worth a try, I found when I went from 180 down to 170, the engine/exhaust noise over 3/4 throttle changed, top speed also dipped by 5mph as did having 190 jets fitted. Another thing to bear in mind that with your new barrel with tighter clearances the impulse on the carb is stronger and it will draw more fuel through the jet.

The Oldham coupling for the ignition timing. Thanks for adding this. I have the bearing piece but nothing else I have wanted to complete it so I can run the setup. Do you have any more information on this?
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 09/25/15 3:19 pm

Hi Allan, at 190 the MJ is down one step from a stock 200 for a 71 A65 L.
Probably, more air flow from the big bore barrels causing a stronger signal plus original air box and filters., a bit counter-intuitive, when I was younger i thought bigger jets hmmm. No air filters and a mega changes a lot.
I will order up 180s to try.

The Oldham coupling has a separate male screwdriver blade end with a threaded male piece which screws into the idler pinion. This set up gives a more stable points cam which is now supported on its own bearing instead of whirling round in a bush.
The male blade was about 4mm deep, 10 mm wide and a parallel fit in the female side, it would be fairly simple to make from an old bolt ground down to suit.
I used to run with this with no issues,( it would kick back if you pussied out )I changed to EI to get rid of the points, now it will start with a casual lean when warm.

Its a historical novelty, an EI spinning rotor is much more stable than a bump stick thrashing around. I dont think its relevant anymore.
If you want it pm me.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 09/26/15 5:37 pm

After the last chop with new plugs 180s are out,190s are lean 200s going back in.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 09/27/15 3:18 pm

Hi Nick, I believe you, going back to 200s next chance.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 09/30/15 6:15 am

200s back in, running well, still needs a plug chop with new plugs,

Starting settings. Most of the time its a one kick to go, if not then its flooded and a couple of kicks with the throttle open are needed to clear.

Stone cold,
full choke,air temp lower than 10 C, tickle each carb, one kick to prime ,key on, one to fire.

Cold, flood each carb, one to prime etc.

1/2 hot, after stopping for a blether and a cup of tea.
Either tickle one carb, or full choke, I have just started experimenting with the choke for this, as soon as it fires put the choke off. One carb flooding seems to be enough for this ( handy balance pipe in the inlet manifold must share this out a bit)

Hot, a casual swing , no throttle.

I have the idle set to a shade over 1,000 rpms, this helps when cold, it will idle steadily with the choke on at just under 1,000, rising quickly as it warms up.
Lately we have had balmy weather and the fully cold process hasnt been needed.

It will start from cold on full choke no tickling, but only on a bump start ( I live at the top of a short hill and quite often , bump to go when leaving the house, it saves a lot of noise / upset neighbours.

Posted By: JER.Hill

Re: alloy barrels for 750 OIF 1971 - 09/30/15 1:40 pm

Nice on Nick
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 10/03/15 9:09 am

Last fill, after MJ test so about 6 float bowl fulls short,

"Your real-world MPG average is 50.28, covering 168 miles using 3.34 gallons of fuel."

Not too bad, considering there was barely about 40 miles of cruising in top for that last tank, consistently over 50 mpg, up to 66. I will try and put in the Glen Coe loop on the next tank, that will give about 100 miles of cruising for a comparison.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 10/07/15 11:53 am

last fill, no long runs.
"Your real-world MPG average is 63.22, covering 111.6 miles using 1.77 ( imperial) gallons of fuel."

Pretty good, the oil is getting changed today,2.5 K ish since the rebuild. Barely used a 1/2 pint since the last change, its about 2" down the dip stick from full.
Its not leaking anywhere. Although there is a bit of discoloration around the front of the rocker box gasket. Its an old component, been re used a few times , It can get changed at the next look at the tappets.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 10/08/15 1:09 pm

Ignition timing.

Since the rebuild I have noticed a bit of pinking at around 2,900 rpms when giving it a handfull.

I hadnt touched the timing for about 15 years, today I retarded it about a mm at the boyer plate.
result, no more pinking, no drop in performance. Motor is happier at low revs. Seems to pick up smother.
Modern fuel,maybe, the motor is also higher comp now. perhaps a combo.
Posted By: Allan Gill

Re: alloy barrels for 750 OIF 1971 - 10/08/15 3:05 pm

You were quite possibly over advanced before, I've found when I have retarded the ignition it will rev harder but will loose some of the midrange and suffers with idling, which is ok if your "scratching around" I used to advance it again if I knew I was going to be stuck in traffic anywhere or slower riding. I would retard it as low as 31

This is using the pazon sure fire which retards a couple of degrees after 5000 rpm, the black box Boyer continues to advance.

Since doing the head porting mods, I tend to leave the ignition advanced, it still knocks the max rpm down but it will pull better in all the gears.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 10/09/15 8:03 am

Cheers guys,
the 750 kit is not new, it had the iron Devimead version previously, sadly any squish effect is mostly gone, in my youth I had removed the lip formed by the head to barrel difference , just radiused and blended near the ports. i think the difference is the higher comp, it was only about 7.5:1 before. Now somewhere above 9:1.
Yeh Im impressed by the oil consumption as well, previous life it needed a top up every 200 miles or so, although I was guilty of the classic error, topping it up when cold before a run , then losing a pint or so out the breathers as the sump full returned. With daily use wet sumping isnt an issue but if left for a week or more it does drop a fair bit.

The fuel mileage also surprises me, it was never thirsty, but this is economy motoring, I ride at a good clip, most traffic is dispatched with by a change to 3rd then a good handful to 5 K or so. Lately the bike has seen much more full throttle than normal, trying to get meaningful MJ readings has seen much more sound and fury than normal riding. I do think the 30 mm carbs are perhaps strangling the top end or so, but the middrange driveability is so good , real world conditions 99% of the time they are a good compromise.
A small bikini or nose cone fairing would help even more here , when I fitted a Puig windshield to the Cagiva I got another 15 miles before the tank warning light came on. (160 -175 miles)

This is the first rebuild using the dry ring build technique , also I gave the 2nd comp ring a few more thou clearance ( 13 versus 10 for the top ring) after reading an article someone posted here. seems to work well. The improved ring seal must help keep blow by to a minimum

This Winter the motor is coming out for a gearbox refit, I have my name down for one of John Hill's 5 speed clusters, 4 out of the batch of 5 are now spoken for, if anyone fancies the last one ( it has the outrigger plate advantage and no plain bushes, all needle rollers), while thats happening I will check over the pimp and feed NRV. The pump was a fresh iron rebuild about 10K ago, I dont think thats the cause, hoping its the NRV.

While I am at it the head is coming off to get the guides lined, maybe a small end re-bush as well, the new pistons gudgeon pins were not as tight a fit in the rods as the old ones, some rock was just perceptible.

Day to day riding is a different regime, no need to empty the sump, or free the clutch.
The clutch has held out well, behaving very well, even behaving in traffic, it gets a hard life with the hilly terrain around here and the high first gear.
Most times the only routine maint lately has been chain wear. The chain is an old renolds,if I can feel it flapping around through the LHS footrest I know its time to adjust. I got two clicks out of the front brake micram adjusters the other day,reset to one , so the shoes are bedding in a bit, no real difference though , the stopping is just adequate and not up to modern standards, the same lever pressure on a twin disc set up would have the front locked . Stopping distances are close to twice the Cagivas for similar speeds.

When I dumped the motor fluids the other day I noted the motor oil was still fairly clean looking , discoloured but not jet black ( from tawny brown fresh), the Primary Atf was jet black (Cheap Comma ,ATF red originally), the gear oil was not emulsified! and still looked as fresh as new stuff, ( Cheap Comma 75/90 semi synthetic.), thats after a winter gathering condensation in the shed.
The magnetic sump plug showed some ferrous debris , so something is still bedding in / wearing out.

RK Leightons have the old narrower seat base and are currently refurbing with new foam cover and top, the planks days are numbered.

The disc front end is still a definite maybe.
THE MZ steering stem needs to be pressed out and a stepped down stem refitted, they press out with no drama, a stepped copy, with MZ yoke lower OD. reducing to the 0.75 OD BSA stem will be threaded to suit the BSA top nut , the MZ top yoke can either be dropped style Alloy or flat with clamps to allow stanchion height adjustment, probably go with the latter. The MZ ypke will have a sleeve to match the BSA top nut. Will probably go with the steel top yoke to allow height adjustment initially, this will work with no stanchion surgery.
In general the MZ front end is fairly robust although the bottom yoke is not as beefy around the stanchions as the BSA.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 10/10/15 8:02 am

"I bet it felt heaps different,",

Indeed , it vibrates more and the engine note is more snorty.
really, it was so long in the shed before i fitted the new barrels I couldnt draw any real performance conclusions.

The main change has been more mid range , compared to the original as I found it, siamese with short mega it picks up its skirts a little earlier. The mega set up had a dip below 3.5K that is now gone.
The piston crowns were de - edged , if thats a thing , all sharp corners on valve pockets radiused.

Wheel alignment.
Thanks to another thread about tyre sizes I found a massive error in my chassis.
My usual chain tensioning regime is to count the adjuster flats on each side as I tension, this is not foolproof.

Spent a good hour with a piece of string checking the wheel alignment.
As found with the string parallel to the rear wheel there was a 25 mm difference, the rear pointing to the timing side at the front .
It was off by about two whole turns on the Timing side chain adjuster, this may explain the rapid chain wear. There is now very little clearance between the tyre and the chainguard, no rub though.

Took it for a quick run and everything is good, no real difference in road manners, it just shows how is easy it is to neglect basic stuff,
Its years since I checked this, shocking!
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 10/12/15 8:16 am

Some fresh pics.
Wonderful sunsets this time of year, down at the Taynuilt pier.
[Linked Image][Linked Image]

The MK VIII brake pedal rearset , old stop deleted, extended SHCS now locates lever arm, after a bit of trimming to suit.
[Linked Image]

The MK IX will delete the stack of cork packers, will relocate the striker after extending the threaded portion of the rod.
A far better peg to pedal angle, foot now stays on ped to operate lever.
[Linked Image]

The brake rod pivot is now closer to the swingarm pivot, good,
[Linked Image]
The rod has a straighter pull with the arrestor hook deleted, and the peg sits more inboard as well, good.

Tidier control layout, although the clutch cable covers the 30 mph zone.
[Linked Image]

Subtle re routing of speedo and tacho cable, now outside lamp brackets, instruments sitting more outward and less cockeyed.
[Linked Image]

The throttle cable could do with being a tad longer, the idle rises on full right hand lock, may fit swept angle tubes at the bar end to tidy up further.

Posted By: Ger B

Re: alloy barrels for 750 OIF 1971 - 10/12/15 8:40 am

Wonderful sunsets this time of year

Posted By: TR6Ray

Re: alloy barrels for 750 OIF 1971 - 10/12/15 1:15 pm

Love that cloud picture, Gavin. I also like to watch you keep fettling your BSA getting it just the way you want it -- MK IX? Wow, persistence. beerchug

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 10/12/15 1:42 pm

Cheer gents.
Every time a non stock component is added there is a trial period, I can see why folk go for all stock bikes, but I am too far down this particular road. I hated the stock pegs, tried them for a while, rubbish except in town or bimbling along back roads, terrible above 60 mph. I dont like the stock shift pattern much either, pressing down for up is my preference.

Spent time on the front end today, fitted the new axle/ spindle the bearing fit was long gone and the old one had definite wauchle/ looseness.
[Linked Image]

Took off the old brake shoes, compared to new EMGOs they were about 1-2mm worn.
Stuck 80 grit strips into the drum with bits of double sidd tape.

[Linked Image] Fitted the brake plate and arked in the shoes.

[Linked Image]

Hatch marks almost gone
[Linked Image] Refitted and took it for a run. What a disappointment, new arked shoes may take some time to bed in but initial result were poor verging on dangerous. The old shoes are going off to SAFTEK for relining , that couldnt be any worse than the new EMGOs, if this works the disk conversion may move down the list of things to do.
Last fill, lots of 2nd and 3rd gear low speed work possibly brought this down or the retarded timing, hmm, need a decent run for comparison.
Your real-world MPG average is 47.49, covering 115.2 miles using 2.43 gallons of fuel.
Posted By: Allan Gill

Re: alloy barrels for 750 OIF 1971 - 10/12/15 2:25 pm

New linings is always best. If you send the drum as well they will check the drum for true and usually fit linings the correct size. My drum had to have 040' taken off to get it true, and over sized linings were fitted. It did take some time to bed in even still although I was told it didn't require bedding in, as it went from being gentle braking to too good. .... Although it seemed to improve after I reverted to the 68' style brake plate.

Bike looks good, nice pics!

I hear you on the rear sets, the standard pegs are a little too much "armchair-ish" in my opinion where as the rear sets keep you in the seat better and feel better when handling the bike though bends. ( that said I'm going to have to revert to stock pegs as I'm fitting twin pipes again)
Posted By: Adam M.

Re: alloy barrels for 750 OIF 1971 - 10/12/15 5:44 pm

Gavin, I was lucky to find a shop repairing drum brakes for cars and bikes in the nearby town.
They skimmed my drum and arced my shoes with a new linings. After putting everything together I build my peg on the slider to be really tight in the front brake plate.
The result is fantastic, 2 finger brake locking the wheel on dry pavement.
The cost was $60. -:)
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 10/12/15 8:48 pm

There is local bloke who will do the wheel/ drum on a mill ( looking forward to seeing his shop, he does a fair bit of high end work), I will have the shoes fitted over size from Saftek and then machined to suit the drum locally.The shoes are off in the post tomorrow. There is no sensation of ovality in use but I cant deny the drum looks worn, there are a few rust pits that wont be helping, not huge but not clean either.
I hope the spongy feel of the emgos is only a passing phase in the meantime.
Posted By: Allan Gill

Re: alloy barrels for 750 OIF 1971 - 10/13/15 3:14 am

Best aftermarket shoes I bought were Ferodo, they are in the rear of the A65, the fronts are as mentioned above. Also put a set in the bantam and now we have a bantam brake that works really well.

Not to worry you but I have heard that the emgo shoes are for a Morris minor or something of that ilk and gave different liner requirements. If they are only temporary then dont worry.
Posted By: kommando

Re: alloy barrels for 750 OIF 1971 - 10/13/15 5:51 am

Don't think that Emgo are the sole Morris Minor copyist as BSA/Triumph did it first, but they did change the lining spec smile to something less hard, only keeping the shoe and the micro adjusters.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 10/13/15 12:46 pm

Today , I got another click on the brake adjusters as they bed down, not as spongy as yesterday and working reasonably after 40 miles of light use.
Posted off the old ones.

Inspected the primary chain, topped up the oil level, and adjusted the tensioner by 3/4 of a turn, quieter now, and a cleaner down change ( this had been getting a little stiff). The front tube has a slow leak, found at 25 psi restored to 32 and whitelining issues have been banished, weather now summer ( in October!) clear skies but a nip of frost in the morning.Light leather jacket weather , woo hoo.
Posted By: kevin roberts

Re: alloy barrels for 750 OIF 1971 - 10/13/15 1:18 pm

gavin; this is a wonderful story, you know.

ive been following it from the start.

to be never-ending, obviously

cant remember tho, what are the bars from?
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 10/13/15 1:25 pm

I think the bars are off an MZ TS 250, nice quality triple plated chrome, some of that MZ stuff is great quality ( Mag alloy subframes anyone? on the cheap 125s!) they have been kicking around the shed for years.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 10/17/15 1:28 pm

Latest , running around
Your real-world MPG average is 52.71, covering 152 miles using 2.88 gallons of fuel.

The front brake has now bedded in , the Emgo shoes are much the same as the old ones, cant wait to try the SAFTEKs when they come.
The old girl and I had a great wee brake, quiet roads, glorious sunshine and a wee bboat trip to Tarbert. Some pics of the trip.

Took a trip down the Clyde, on the ferry quay at Dunoon.
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On board the ferry, it was like a millpond so the centre stand was OK.
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Basking sharks seen from Saorsa on a cetacean hunt.
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On the esplanade in Fairlie, where they used to make Fyffe yachts, coal terminal in the bay.
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Going to Gogo st.
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Stopped at the Whisky shop in Inveraray on the way back
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The boat every one loved
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Summer in October, bring it on, getting nippy at night though, no sign of the usual equinoctial gales. Its a big El Nino when the sun stays out for days in Scotland!
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Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 10/17/15 3:10 pm

Just a comment on the Dunlop Arrowmax tyres, after 2,500 miles they white line terribly, also track very poorly on longitudinal rutting, I wont buy them again. They were OK for the first 2K but I expect better service than that.
Posted By: TR6Ray

Re: alloy barrels for 750 OIF 1971 - 10/17/15 5:53 pm

Thanks for the pictures, Gavin . . . traveling in the footsteps of Saints and Kings. It all seems pretty exotic from over here!

Posted By: Adam M.

Re: alloy barrels for 750 OIF 1971 - 10/18/15 1:34 pm

Thanks again very interesting to see old Scotland.
I'm very happy with my new Shinko 705 road tires on A65, but don't have enough miles on them to be sure they are really good buy. Anyway can lean on them 2x deeper than my old Bridgestones allowed smile.
No longitudinal routing, good in rain even on white lines for now.
You already know prize wise it was a steal smile.
2 for $ 110 or something like this.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 10/18/15 2:30 pm

Not sure if we get Shinkos in the UK, they look very different to normal street tyres, could be useful around here , I use a few farm tracks.
Was thinking of going for Avons, but I might try these if I can find a source.
Posted By: Adam M.

Re: alloy barrels for 750 OIF 1971 - 10/18/15 4:51 pm

Sorry Gavin, wrong number.
I meant 712 -
Read a last review, exactly my sentiments about them.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 10/20/15 4:17 pm

They sound good, not easy to get in the UK Amazon says not currently available.
The LBS is getting me Avon Roadriders for 130 a pair, giving them a try.
Fitted an LED voltage monitor to the Lamp bucket central idiot light.
Very useful, even with lights on I am getting a good charge at 2000 ( green ), Discharge at idle ( red) changing to OK ( amber) as soon as it leaves idle, on the strength of this I will wire in a 30 Watt x2 LED spotlight to the main beam circuit, to replace the QH 45 W in the bucket.
Posted By: Ger B

Re: alloy barrels for 750 OIF 1971 - 10/20/15 4:29 pm

This ex seaman is a bit curious what "Gogo Street" offers in a port town... beerchug
Posted By: Allan Gill

Re: alloy barrels for 750 OIF 1971 - 10/20/15 5:02 pm

I think we have all been ex seamen at some part of our lives whistle

Sorry, couldn't resist
Posted By: jhays79

Re: alloy barrels for 750 OIF 1971 - 10/20/15 5:56 pm

Just wanted to say I love following your adventures with your bike and all the improvements you've done to it. I especially like that you really ride the bike and put it through it paces. well done! Keep it coming!
Posted By: Ger B

Re: alloy barrels for 750 OIF 1971 - 10/21/15 1:10 am

think we have all been

I like the way you think, Allan. laughing
Posted By: JER.Hill

Re: alloy barrels for 750 OIF 1971 - 10/21/15 2:43 am

I was going to mention a few places, but decided against it on possibility of self incrimination. (need to find out how to do these smily things.

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 10/29/15 1:19 pm

The seat came from Leightons, it bolted on with no issues! the catch works as well!
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another first for mankind. A great firm to deal with, the old base looks great in the fresh paint
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and riding comfort is much improved with the narrower nose.

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Plank no more.
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Tool kit and welded front hinge ( done years ago)
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Your real-world MPG average is 53.38, covering 151.4 miles using 2.84 gallons of fuel.

I left the fuel tap open by mistake overnight, there is leakage around the carb Banjos, drip marks on the casing were the give away.. Will order new filters and see if that helps. may eke out another mile or two.
Weather is distinctly Wintery now , salt on roads means the old girl can rest here heels soon. Winter tart up time.
Posted By: Allan Gill

Re: alloy barrels for 750 OIF 1971 - 10/29/15 1:29 pm

bike looks great Gavin!, Leighton's do excellent work!

Are you saying there is a paint job in the mist?
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 10/29/15 3:12 pm

Aye a paint job, I hate the idea of taking apart a perfectly good bike, but the riding season is nearly over and there is welding work needed on the side stand mount and tank mount. At the same time , while the motor is out the 5 speed box will be fitted JH has them fully sorted now. I will brush paint the frame , get the tank farmed out for a refresh and paint the air filter housings.

Excuse the following woolly minded prose.
I normally avoid anthropomorphism, although i occasionally refer to the bike as " the old girl", normally I think of it as gender neutral and generally refer to it as " the Beesa", as if it was some sort of creature living in the shed.
As soon as the bike is apart its as if the beesas soul begins to evaporate ( total bollox I know, but the whole does seem to me to be much greater than the sum of the parts), for me this is a worrying time. Ive always felt that way , for the whole time Ive owned this bike its never been fully dismembered.
Especially since everything is working well at the mo. All the lights are working, its not using oil, mpgs are reasonable and the seat catch is working properly for the first time ever. Having a working side stand would be the icing on the cake.
Luckily Ive nothing better to do so lets have at it.

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 10/30/15 6:11 pm

In at the LBS today , their was a T140 on the bench that had 140 psi on the compression tester, checked the BSA on the same gauge, warm motor , throttle wide open, 6 kicks, 200 psi each side!?.

I dont believe the figures , will check on my own gauge.
Posted By: Allan Gill

Re: alloy barrels for 750 OIF 1971 - 10/30/15 8:14 pm

It's possible depending on compression, the 650 spitfire was noted at something like 160-180
Posted By: triton thrasher

Re: alloy barrels for 750 OIF 1971 - 10/31/15 4:49 am

I don't know what an LBS is, but I saw 185 psi on a T110.
Posted By: kommando

Re: alloy barrels for 750 OIF 1971 - 10/31/15 6:00 am

Local Bike Shop ?
Posted By: triton thrasher

Re: alloy barrels for 750 OIF 1971 - 10/31/15 6:07 am

The compression gauge is for showing that there is not an acute compression loss problem, or a strange discrepancy between cylinders.

Worrying about some other bike showing 140 and yours showing 200 doesn't make much sense to me.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 10/31/15 7:29 am

Im not worried, it just seems suspiciously high,yes, Local Bike Shop, when first built my compression readings were 145 RHS ( different gauge) , 125 ish LHS, cold motor.
Posted By: Adam M.

Re: alloy barrels for 750 OIF 1971 - 10/31/15 9:12 am

Hi Gavin, what was the cost to refurbish your seat at Leighton's, I have to rebuild mine during a winter and think about sending it to them.
Local rates are high, so why not to have good quality if I have to spend the money anyway ?
Posted By: triton thrasher

Re: alloy barrels for 750 OIF 1971 - 10/31/15 10:01 am

There isn't a fault, known to me, that causes too-high compression gauge readings.

Maybe monster compression ratios could, but if you're building a go-faster old bike, you measure the compression ratio.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 10/31/15 12:07 pm

Hi Adam, I supplied the old base and top patterned vinyl. Leightons , blasted , painted and repaired the seat catch, fitted new foam and cover to my spec, I wanted black piping and chrome trim with BSA logo, total bill 160. I asked for the thinner foam option, but its still a little thick for my tastes.
Re compression figures, I am more than happy with the readings , just feel that the LBS gauge was perhaps a little optimistic. The BSA manual for the 650 at 10.5 to one give pressures of 185 avg, so close enough .
Posted By: Allan Gill

Re: alloy barrels for 750 OIF 1971 - 10/31/15 1:14 pm

The best way to tell us with a leak down gauge, cheap as chips if you already have an air compressor
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 10/31/15 2:53 pm

I dont own an electric compressor , but I have a bike track pump. I may rig something up for that , using a dead spark plug and a bit of pipe.What are the specs for a leakdown test, starting pressure?, decay rate?
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 11/18/15 3:05 pm

A few pics off the camera, the weather is dire at the mo, hail, thunder , lightning. Indoors for days now.

A bit of Autumn colour from Pulpit hill in Oban a couple of weeks ago, looking over the Firth of Lorne.
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Kerrera marina in the firth, once a base for flying boats
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Dunstall swept backs with blance pipes, these neck down to a reduced OD after the blance pipe, may fettle them up over the Winter.
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Thet were off a Norton I think, Ive had them kicking around for years, the balance pipe stubs need re welded to suit the A65, some dents need pulled out, then re chroming. purely for experiment, Paul Dunstall thought they made Norton twins go better , maybe it will work on BSAs as well.?

Old Dunlop rear , just under 3,000 miles, thin in the middle, new Avon mounted.

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Scabby rear brake plate, will daub some silver paint on it.
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Old Dunlop front, new Avon front mounted, the wavy centre sype is supposed to stop white lining, we shall see.
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Bought a NOS lower yoke from ebay, , off to speak to a man with a machine shop about boring to suit MZ legs.

I have fitted the new front brake SAFTEK linings but havent had a chance to try them out yet. Waiting for a dry spell, it may be weeks or months the way things are at the moment. Heres to Spring.
Posted By: kurt fischer

Re: alloy barrels for 750 OIF 1971 - 11/18/15 7:43 pm

Like the pics, Gavin, I know the feeling, ride when you can, never know when the foul weather will settle in.

Posted By: Adam M.

Re: alloy barrels for 750 OIF 1971 - 11/18/15 9:07 pm

Did my last short ride today and put the bike to the garage for winter.
End the ride was great, again I realized what a fantastic package this bike is. Light and flickable with powerful acceleration and brakes to match.
Some bad weather prevented me to ride during early September, but we got decent weather even today and tomorrow. Viva el Ninio !
During winter I have to reupholster the seat ( falling apart on every seam ) and repair my clutch.Times come where I will be forced to sell my old girl - can't ride two bikes simultaneously, no enough space for two in my 1 car garage.
So I wonder what to do - come back to original and keep all parts making this bike so special, or sell it as is ?
When I sell the original 70 Thunderbolt I still can build a real special with 500 bottom end, 650 top end with my very good cylinder head and nice 66 / 67 set of clothes.
So I'm really tempted smile.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 11/18/15 10:07 pm

Do not sell a running bike you enjoy riding , that is madness.
Leave the car out in the rain maybe? So long as the heater and windscreen wipers keep working thats all they need.
Posted By: Adam M.

Re: alloy barrels for 750 OIF 1971 - 11/19/15 10:20 am

It's not a madness Gavin.
For me BSA has 2 flaws:
- pre OIF is the small bike and after I retire I'd like to take my wife with me from time to time,
- it still vibrates and this tires me so every trip longer than 200 km is a problem.
This is why I wanted to try a Trident, which is not as big and heavy as my old Japanese bruisers and its still a Britbike.
Posted By: Allan Gill

Re: alloy barrels for 750 OIF 1971 - 11/19/15 3:36 pm

Get the crank balanced to 72%, make sure all the mountings are tight and the bike can breath properly, just just through the carburation but crank case breathing as well. Lastly, tweeting the timing a degree or two either way always seemed to make the bike that little bit smoother than when at the 34 setting.
You'll be surprised how smooth you can make the A65!
Posted By: M Shearer

Re: alloy barrels for 750 OIF 1971 - 11/19/15 5:48 pm

Originally Posted by Adam M.
It's not a madness Gavin.
For me BSA has 2 flaws:
- pre OIF is the small bike and after I retire I'd like to take my wife with me from time to time,
- it still vibrates and this tires me so every trip longer than 200 km is a problem.
This is why I wanted to try a Trident, which is not as big and heavy as my old Japanese bruisers and its still a Britbike.

Adam why not try a Commando. Riding them is like a magic carpet ride compared to an A65 and the torque is just fantastic.
Sorry for the temporary Hijack Gavin.
Posted By: shel

Re: alloy barrels for 750 OIF 1971 - 11/19/15 6:28 pm

Originally Posted by Adam M.
no enough space for two in my 1 car garage.

I have 5 motorcycles and 2 mnibikes in my one car garage
Posted By: Adam M.

Re: alloy barrels for 750 OIF 1971 - 11/20/15 6:19 pm

Allan when I was your age I wouldn't feel any vibrations smile
My crank is balanced dynamically to 72%, I believe some vibes are added by my clutch.
I'll work on it during winter.

M. Shearer too late - I bought a Trident.

Shell, problem is my one car garage is a home of my full size van full of equipment.
To fit a BSA there I have to take off one footrest and rear brake pedal.
Now I'll shut up and let Gavin continue.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 11/20/15 9:19 pm

Took a spin,( A nippintae toon fur the messijes) fitted the new rubber and Saftek brake linings, huge improvement, still bedding in but very good first impressions. Cold, fair and dry to hellish spray and salty.
Rinsed the bike down, its coming ben soon. SWMBO is away fer a week , bikes in and its comin tae bits.

[Linked Image]

Salt on your egg Sir?
Posted By: Allan Gill

Re: alloy barrels for 750 OIF 1971 - 11/21/15 3:39 am

Originally Posted by Adam M.
Allan when I was your age I wouldn't feel any vibrations smile
My crank is balanced dynamically to 72%, I believe some vibes are added by my clutch.
I'll work on it during winter.

laughing thanks almost cute. I am being straight up though. My A65 used to cut in like a switch for vibrations when it hit 4000 rpm, just below that and I could ride it all day. But there are different things that will cause it, poor fuel mixture is one. It's not purely about the crank balance. Having damaged my back I am sensitive to bikes vibrations though, and I can notice them more on the Honda 400/4 than on the A65, even at high revs. I also agree about the clutch.

Anyway, apologies Gavin,
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 01/22/16 7:55 pm

Happy New Year one and all.
The Gavistan nativity scene,
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Its oot wi the auld, in wi the new time.

Heres the auld.
Cosmetically the bike is a 20 footer, close up its grim, a month in a damp shed brings up the rust lovely.
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Although the bike is running well I have a few jobs to do over the Winter.

Job list.

Fit 5 speed gearcluster,

I am taking the motor out for this and splitting the cases to help fit the clutch support bearing , so while its apart the crank is getting balanced, the drive side crank journal needs a bit of slack taken up with Copper plating, its slightly oval. The cylinder head will be sent to SRM for a valve seat tidy up on the Serdi, maybe liner the valve guides as well, Spark plug threads need inserts , doing all the plug chops I was aware of the threads losing their crispness.

Frame welding,

the tamk centre mount bracket is FUBAR,

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the side stand bracket is non existent.
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Steel lugs to frame for permanent rear set mounts.

The seat rail is in very poor condition, seat rubs
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The wiring will be renovated as well
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Choke cable chafe, the noodle is doing a great job, throttles feel very good
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Rats nest wiring under frame , showing grommets and brake cable guide.
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Generally poor paint and rust
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Mud flaps required.
Coming soon , shiny new bits, electrolysis, dirty fingernails.
Awra best.

Posted By: Triless

Re: alloy barrels for 750 OIF 1971 - 01/22/16 11:26 pm

Thats the point, NickL, warm them up! There's three different coefficients of expansion that need to stabilise. Alloy head, cast iron cylinder block, steel pushrod tubes! ( YES! YES! I know! ).
With my Special ( T140 engine ) , being built of disparate parts, I did have an initial ( slight ) problem with leaking pushrod tubes, but alloy ones solved that.
If I could afford it, alloy barrels would be fitted here in a flash!
Posted By: Triless

Re: alloy barrels for 750 OIF 1971 - 01/22/16 11:42 pm

By the way, Gavin, good model of a Cromwell ( or is it a Comet? )
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 01/23/16 12:39 am

Cromwell I think, the Crusader had the slopy turret armour.The baby Jesus is in the tank.
@NickL , yes , outrigger in primary, replacing the seal carrier behind the clutch , the new 5 speed box has some beautiful pieces. Pics later.
Posted By: Triless

Re: alloy barrels for 750 OIF 1971 - 01/23/16 3:06 am

I'll probably be kicked off the forum for this total hijack, but I'm an anglophile, and that is that!
The Crusader was a fast tank, and used a lot in the Western Desert, but had a few reliability problems. The Cromwell was a good tank, but the Comet was better.
At the boarding school I attended in the ' 60's, the junior house master, a transplated Pom. was a sargeant driver in the RTR, and he reckoned the best tank he ever crewed was the Comet!
Whats this got to do with motorcycles? Nothing, really, but Gavin put up the pic of the model tank! Extrapolation, I guess.
Anyway, Triumph. The Best Motorcycle in the World!
Posted By: kommando

Re: alloy barrels for 750 OIF 1971 - 01/23/16 7:01 am

Have an original mudguard on the Norton, all my other bikes get them fitted as it does work. Skimpy mudguards look cool but in West Scotland conditions do not work, so either move to sunnier climes or fit mudguards. Also another reason to stay with factory specified thin tyres instead of cool looking wide tyres.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 01/23/16 9:25 am

The tanks back story, my old man was in the Polish 1st armoured division and captained one of these things. The allies kept the 1 st armoured div in Scotland until the final push in France, from 1940 -44 they were building coastal defenses in Scotland. No match for Tigers and Panzers the Cromwell was fast but under gunned and under armoured in comparison, I have a pic of my old mans tank somewhere showing welded on man hole covers as added Armour. He was invalided out with a leg full of shrapnel after the Battle of Falaise and met my mother to be in a hospital in Glasgow.

back to the bike.

The outrigger plate John supplies with the 5 speed cluster need careful fitting , he advises this is best done with the cases split, some trimming of the mounting flange may be needed.
Also John has found with the cluster fitted in his test bike , there are some minor clearance issues with subtle amounts of casing removal needed for the extra gears, this was very minor on his bike, but the later 71 castings are a little heavier all round so I expect I may have a little more work to do.
@kommando, i have been down the tyre width changes before, back to stock widths after pointless experimentation.

The alloy tank has been welded up at Ramsay ladders , I now need to find an oven large enough to anneal it, 390 -410 C ( I think?) , the pottery up the road may be able to help .
Posted By: Lannis

Re: alloy barrels for 750 OIF 1971 - 01/23/16 11:17 am

Originally Posted by Adam M.
It's not a madness Gavin.
For me BSA has 2 flaws:
- pre OIF is the small bike and after I retire I'd like to take my wife with me from time to time,
- it still vibrates and this tires me so every trip longer than 200 km is a problem.
This is why I wanted to try a Trident, which is not as big and heavy as my old Japanese bruisers and its still a Britbike.

I've been in exactly the same situation.

As Allan says, the dry frame BSA can be made to be very smooth with dynamic crank balancing and an EI to make sure cylinder firing is synchronized.

However, be sure to sit on a Trident or Rocket with your wife before you make the plunge. The motor is certainly as smooth as anything you will find, and plenty of pull for two-up, but physically it's not really much longer than an A65 and will not have much more room. Check it out first.

In my situation, I bought a Commando. About 2" longer and two disc brakes ......

Posted By: shel

Re: alloy barrels for 750 OIF 1971 - 01/23/16 11:34 am

I was reading about a guy moaning about the vibration of his Trident but after 35 years of riding twins when I get on my Trident I have to say "what vibration?"
But, no, it isn't any bigger than my OIF Bonnie
Posted By: Allan Gill

Re: alloy barrels for 750 OIF 1971 - 01/24/16 8:13 am

Originally Posted by Lannis

In my situation, I bought a Commando. About 2" longer and two disc brakes ......


Yes, and Andover Norton do some lovely front end improvements too, it was very tempting to get one of their twin fully floating disc setups to squeeze into the beezer, very stylish!!
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 01/24/16 5:21 pm

Strip down continues at a leisurely pace, today I removed the air boxes, chain guard , carbs, loom, battery carrier, rear mudguard with tail light and grab rail came off as one unit , handy.

Discovered an unknown defect, the coil carrier bracket has fractured where it mounts at the rubber on the timing side, weld needed. The TS airbox mount bracket has lost its captive nut, more welding.
Apart from being filthy everything came apart with no grief.

New carb brass plated slides still in A1 condition. Not much muck in the fuel filters at the banjos.

The skankiest part so far is the battery carrier rubber tray, this has turned into a sticky mess, the DS side panel rubber has seen better days as well.

An old original fault may be dealt with , I have never been able to stop the coil bracket from saying hello to the side panel, even with the panel as far outboard as the slot will allow, I think this and the added weight of the voltage reg rec may have caused the crack. needs a new location for the reg rec.

Much to my surprise all the loom connectors parted correctly, I will re use about 75% of the loom, replacing the ignition circuit and adding a few relays

I am considering 55% as a balance factor, this should move the sweet spot up the rev range a bit, currently starts getting rough at 5K plus.
No real surprises so far.
Note to self, run the loom under the coil bracket not over it.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 01/25/16 7:58 am

Thanks for the gen Nick. My current gearbox shifts pretty well, but I have spent a fair bit of time setting it up, it does not shift well on the down change when the primary chain gets slack, other than that its good. I like the lathe plan, thats do -able.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 01/25/16 3:01 pm

Pics of new shiny bits.

5 speed cluster, lay shaft to fore showing needle roller for 1st.

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Selector plate with lovely finish and extra track for selector.

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Outrigger bearing and plate.
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Outrigger plate mounted on mainshaft showing splined mount for clutch centre.

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Main shaft sleeve gear needle roller bearings

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Cluster with selector forks loose assembly

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Fork stanchions , seal, lamp bucket, wires , gears.

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Rear mudguard assembly and airbox

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The end of the pencil indicates the cracked zone of the coil bracket
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Carbon fiber side stand 133 grammes , 10 from China. I will not pay 100 for a steel club.
Better the stand is the weak point than the frame tab.
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The camera certainly adds an extra scabbiness to the before pics. I will be treating rust with electrolysis, brown soup to follow.
Posted By: Zombie

Re: alloy barrels for 750 OIF 1971 - 01/25/16 6:41 pm

Insanely jealous of the five speed set up.

I'm waiting to find a complete engine for the price those sets are fetching.
Posted By: Adam M.

Re: alloy barrels for 750 OIF 1971 - 01/26/16 10:00 am

Entertaining winter read as always, Gavin.
I just powdercoat my frames and hidden bits mainly for resistance to scratching and a low price.
Your decision to buy a five speed cluster still looks much better and cheaper to mine of buying another bike with a five speed smile.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 01/26/16 3:18 pm

Hi Adam, I am undecided about what type of paint to use for the frame. It wont be shotblasted, thinking of a Caustic Soda marinade after power washing with citric acid. Will probably use a brush for the frame and get the air boxes blasted and sprayed black locally.The list of frame repairs is increasing.

Manufacture and weld a slotted saddle for the tank centre mount.
Manufacture and weld a side stand bracket.
Same for footrest mounts, 2 x 1 inch OD bosses, radiused to frame tube OD tapped to suit peg mounts ( 3/8 th UNF).
Re weld the air box mounting fixed nut ( 1 x 5/16 UNF).

Trim the coil bracket and hanger brackets to prevent fouling with side panels.
Weld crack in coil bracket, trim coil bracket around perimeter to prevent fouling with side panels.

The good news is the Swing arm bearings are OK, I replaced them in 1983, and have greased them with a zealousness that can only be attained after pounding out the seized solid previous swinging arm spindle..
I am very curious to know how well the taper roller headstock bearings have lasted. I have never had to replace these , I did add fresh grease once about 20 years ago. there is no untoward play or notchiness.

Posted By: TR6Ray

Re: alloy barrels for 750 OIF 1971 - 01/26/16 5:01 pm

Originally Posted by gavin eisler
The good news is the Swing arm bearings are OK, I replaced them in 1983, and have greased them with a zealousness that can only be attained after pounding out the seized solid previous swinging arm spindle..
I am very curious to know how well the taper roller headstock bearings have lasted. I have never had to replace these , I did add fresh grease once about 20 years ago. there is no untoward play or notchiness.


I saw this and wondered how many people in the world still have the motorcycle that they owned 33 years ago -- some do, I'm sure. Out of that number, how many remember that they replaced the swing arm bearing that year -- a lesser number, I'm sure.

Like me, you must keep a "bike diary" for each one. You often make me chuckle as I read your thread, but I always do read it. I'm still trying to decide if you wrench on your BSA so that you can ride it, or if you ride it so you'll have a reason to spanner it. Both, I suspect.

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 01/26/16 5:17 pm

i remember replacing the SA bearings very well, it took a weekend of heat and heavy hammers, ultimately i pre purchased a new spindle and bushes so that I could get serious with the old one, it was so seized that half the old bushes came out stuck on the steel spools. I had to make a special puller extractor and ream the finished item . It had never been lubed! No diary, just memory burned in.
Posted By: Triless

Re: alloy barrels for 750 OIF 1971 - 01/26/16 5:46 pm

Bit off topic, Ray, but I bought my Triumph T140 new in 1976, in fact did the pre delivery on it. It has a rather large note book! Forty years worth!
Oh, and has never been out of registration!
Posted By: Triless

Re: alloy barrels for 750 OIF 1971 - 01/26/16 5:59 pm

This is an interesting thread, Gavin. That gearbox is beautifully made. I'm aquiring all new gearbox bits for my T140 race project, and the bits look a touch agricultural compared those components if yours.
Looking forward to your impressions when its all up and running.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 01/27/16 9:50 pm

@ Zombie , re expense. heres how I budget. look at wrecks on e bay, add on the cost and hassle of fixing some one else's grief , then put that in the back of your mind, dont bid on it and get some quality , one off parts ( sourced from the town where I was educated, by a loon who had the same physics teacher as me) , at a fraction of the cost instead, simple.
Posted By: kommando

Re: alloy barrels for 750 OIF 1971 - 01/28/16 4:57 am

That gearbox does look good, well engineered and well machined too. I see the PES on the outrigger plate, so they do them for twins too as well as the singles.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 5 speed gears - 01/28/16 9:18 am

The clutch fitted is pretty fresh, replaced basket and hub with fresh steel plates and surflex friction plates, its behaving well, no slip or drag so its going back in, not shown in the pics is the clutch centre with female splines to suit. If the clutch was knackered I would fit an alloy item.
Posted By: TR6Ray

Re: alloy barrels for 750 OIF 1971 5 speed gears - 01/28/16 10:21 am

Triless: I've always thought that the best way to get a classic motorcycle is to buy a good one when it is brand new, and then age gracefully with it. So, I admire you for keeping your Matchless and your T140 for so long. You did the pre-delivery on the T140? That's even better.

Gavin: Pardon my ignorance on such things, but how do you seal your primary chaincase with that bearing in place of a seal? I see that it is a "sealed" bearing, but those plastic side pieces are really only good to keep most of the grease in place and most of the dirt out on wheel bearings. They are far from being a real dynamic seal. Also, the bearing is a slip fit on the shaft, so there is no sealing action there. Where does the seal fit?

Also, what is the process for aligning this bearing with the other two on the same shaft? Will there be any machining required to accomplish this?

I'm not being negative here. I hope it all works as you have planned it. Those are just the questions in my mind as I look at your pictures.

Posted By: JER.Hill

Re: alloy barrels for 750 OIF 1971 5 speed gears - 01/28/16 11:38 am

Hi Ray

Written in the assembly instructions describes how to go about the alignment set-up. Unlike early earlier Brg support plates which were on the gearbox mainshaft and indeed requiring the alignment of all three Brg's. On this one it the final drive gear Brg and the support plate which are aligned, while the mainshaft run on needle Brg's through the final drive gear, therefore the mainshaft has a little more tolerance.

With regards to the original seal, this sealed on the final drive gear bush, to ensure that no gearbox oil found its way out onto the rear tyre, as there is less likelyhood of primary chain oil by-passing the seal.

Hope this is of help

Posted By: TR6Ray

Re: alloy barrels for 750 OIF 1971 5 speed gears - 01/28/16 2:54 pm

Thank you for the reply, John. I somewhat follow that. I'm sure it will become even clearer as Gavin shows us his pictures here. Sounds very interesting. I can only imagine next year's riding season in Scotland!

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 5 speed gears - 01/28/16 5:39 pm

I had the priviledge of a test cluster assembly on John's bench, JH also supplied a detailed write up as a memory jogger. Its not quite as simple as the 4 speed ,requiring a specific order of assembly to locate all the selectors.

I havent any major concerns over sealing the primary, hotted up unit singles ( CCM and the like) have used outrigger plates for years. There are 6 potential alignments using the mounting flange , I will use the least worst of these and if needs be modify the mounting spigot to suit. I am more concerned about the size of the outrigger plate fasteners, ( stock is 6 x 2BA fine for a seal carrier , maybe a bit under-size for a bearing load)if there is enough meat on the casings I may enlarge the female threaded holes to 6mm or 1/4 UNC depending on which countersunk heads have a chance of fitting, these fasteners will be fitted with Loctite, maybe stud lock grade. Once fitted I dont anticipate removing the plate until the next gearbox sprocket wears out. John has shown me a few pointers here, it may not be possible to enlarge all the fasteners , on the GB Sprocket side there is space to fit nuts on some of the fasteners if left oversize, but the sprocket gets in the way a bit.

Currently composing a shopping list.

Nyloc Nuts and bolts , misc 1/4" 5/16", 3/8" UNF . SS 1/4" washers, countersunk head 6 off x 1/4 " UNC, half size nylocs to suit.

Battery and side panel rubbers, tray and strap, frame grommets.
Gasket set.
Gearbox sprocket 21 T and chain. Kickstart cotter pin.
Copper Sulphate. Na OH Caustic soda. Zinc plating kit.
Black Paint ( for brushing on the frame, any favourites out there?).

Looking at the headstock zone, there is a bit of free space between the support gussets , I want to fit a breather catch bottle in here so I dont need 4 feet of oil tank breather hose.
Under the seat , space will be freed up by mounting the reg rec to the base of the battery carrier and fitting the boyer EI pack into a side panel with sticky velcro.
Posted By: kommando

Re: alloy barrels for 750 OIF 1971 5 speed gears - 01/29/16 5:45 am

Once you start using the outrigger plate the force that was bending the mainshaft now is placed on the fixing screws for the plate so how you attach the plate becomes a lot more important.

This thread gives some solutions for Unit Singles

Screws coming undone is not unknown so loctite or wiring is a must.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 5 speed gears - 01/29/16 7:00 am

Nick, when you used 5mm screws , did you tap out the existing 2BA female threads or drill and tap new mountings?
Thanks for the link Kommando, very informative.
Posted By: Allan Gill

Re: alloy barrels for 750 OIF 1971 5 speed gears - 01/29/16 8:41 am

I could have sworn the original screws were 3/16
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 5 speed gears - 01/29/16 4:21 pm

Alan you may be correct, 2BA and 3/16 are the same TPI but different thread angles.
Posted By: Allan Gill

Re: alloy barrels for 750 OIF 1971 5 speed gears - 01/29/16 6:19 pm

As you probably know, I had the screws come loose on my main shaft out rigger and destry the primary. I fitted 3 of them after that with those locking aero nuts and red locktite. They never moved again. But I couldn't get the plate off when I needed too either. laughing

But my clutch and box gets a bit of hammer so I'm putting the down to them screws working loose.

I since reverted to the original design.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 5 speed gears - 01/29/16 8:40 pm

Originally Posted by NickL
I tapped the existing holes 5mm.
I ran a 520 chain on the racer so i could get 1/2 nuts on a few of them but they weren't required.
The plate should be a very snug fit and need the case warming to fit it.
On another case where a previous plate had been fitted i had to re-drill and tap the holes for 6mm
as 2 or 3 screws didn't line up properly and were 'cocked'.
If the plate is lined up and seated in the case properly with the case/plate taking the load, they are good. If the plate is loose and you are relying on the screws, they will come out.
SRM used to weld the plates in but that's a pain for anything other than racing.
I used a drop of green locktite which meant warming the screws with a small blowtorch to remove them.

Ecellent info, any thoughts on anti rotation dowells.
Posted By: Adam M.

Re: alloy barrels for 750 OIF 1971 5 speed gears - 01/30/16 1:38 pm

Answer for your question about black brushing frame paint - POR 15, Tridentman swears his life on it smile.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 5 speed gears - 01/30/16 1:40 pm

Repairs so far, canibalised some old switchgear, i now have two correct switch blocks with no holes in the casings. Showing old damaged housing.
[Linked Image]

Electrolysis set up, showing mag bracket. cathode electrode.
[Linked Image]

Bucket of soda solution and battery charger, cathode and anode in bucket ( anode is an old iron stove part ).

[Linked Image]
before coil bracket and headsteady.

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After 24 hours of de rusting. and a 2minute rinse and brass brushing
[Linked Image]
[Linked Image]
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Battery carrier rotten rubber.
[Linked Image]

2 good one bad
[Linked Image]

I am a convert to electrolysis for clean up, stuff thats really bad can take a couple of days.
Posted By: TR6Ray

Re: alloy barrels for 750 OIF 1971 5 speed gears - 01/30/16 2:56 pm


What do you have against glass blasting for parts like this? It could be clean bare steel in a few minutes and ready to accept paint. I don't blast gasket surfaces, internal engine or gearbox surfaces, or surfaces that I intend to polish. Pretty much all else is fair game for the cabinet.

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 5 speed gears - 01/30/16 3:01 pm

You can only piss with the genitalia you have been provided with.

I have a bucket and a battery charger, I dont like the noise of a compressor so I dont do stuff with compressed air. i have had stuff blasted before, but its not convenient where I live now.
Posted By: TR6Ray

Re: alloy barrels for 750 OIF 1971 5 speed gears - 01/30/16 3:32 pm

Fair enough, and a good answer!

Carry on.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 5 speed gears - 01/31/16 9:49 am

Thanks for the POR 15 tip Adam,
Posted By: shel

Re: alloy barrels for 750 OIF 1971 5 speed gears - 01/31/16 12:04 pm

I tried the electrolysis thing about a year ago, I couldn't get it to work using just a charger, I had to connect the charger to a battery and then the battery to the part and cathode, I assumed the battery charger wasn't reading a discharge and would turn on.
Posted By: Adam M.

Re: alloy barrels for 750 OIF 1971 5 speed gears - 01/31/16 12:41 pm

Did you try cadmium by electrolysis ?
Posted By: shel

Re: alloy barrels for 750 OIF 1971 5 speed gears - 01/31/16 1:01 pm

I haven't, I was trying to clean out a rusty fuel tank that I wanted to save the paint on so I was leery of acids and such
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 5 speed gears - 01/31/16 1:30 pm

i think it depends on the age of the charger, my charger is 35 years old, has 6 or 12 volt, low or high charge, when its on for rust stripping I have it on 12 Volt high charge and the ammeter shows almost zero. i read somewhere that modern chargers dont work so well , maybe thats when the battery comes in.
Its a very low impact and quiet process, while its working I get on with other stuff. primary strip down in progress at the mo while it removes rust from the zorst pipes.
The electrolyte is pretty innocuous, its just washing soda after all, i have used the same bucket load for a few weeks now.

Opened up the primary, after removing the fasteners I tapped round the case with a small leather mallet, the tone change indicates when the joint breaks and a bit more oil drops out. to a sound track of 30s blues to sooth the motor demons, Muddy, RJ and Son House.
Note the clutch adjuster screws, the clutch works/worked perfectly , spring balance means one thread protrudes , one is flush and the other is about one thread shy of the adjuster top.
[Linked Image]

Fairly clean,black goo as usual but not much, this was with ATF as the primary lube.
[Linked Image]

Showing primary inner and weld repair from footrest damage near clutch centre opening.
[Linked Image]
Posted By: Lannis

Re: alloy barrels for 750 OIF 1971 5 speed gears - 01/31/16 3:33 pm

Probably time for a new set of clutch springs! Not right away mind you, but maybe the next time you put an order in to one of the vendors?

Posted By: Triless

Re: alloy barrels for 750 OIF 1971 5 speed gears - 02/01/16 4:56 am

Gavin, Son House, I suspected you had a human trait or two!
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 5 speed gears - 02/01/16 7:44 am

Son House is an inspiration to me, I play a bit of old time blues , these are the guys I look up to.
I bought Robert Johnson , Howlin Wolf, Buddy Guy and Junior Wells,Duster Bennet, J L Hooker, Elmore James albums the same year as I bought the beesa.
Studied with Stefan Grossman, who studied with Mississipi John Hurt and The Reverend Gary Davis, thats as close as I could get to meeting the old timers.

Being Scottish I see no need for a whole set of new clutch springs, maybe just two would do , LOL.
Posted By: TR6Ray

Re: alloy barrels for 750 OIF 1971 - 02/01/16 2:41 pm

But don't forget Lightnin' Hopkins. He didn't realize it, but he helped me put my TR6 together . . .

Posted By: kurt fischer

Re: alloy barrels for 750 OIF 1971 - 02/01/16 3:24 pm

Originally Posted by TR6Ray

But don't forget Lightnin' Hopkins.

^^ Saw him perform, in person that is, 1963 I think it was.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 02/01/16 4:41 pm

Cheers Ray , hadnt seen that, how about a bit of Furry Lewis showing a few other ways to skin a cat.
Posted By: TR6Ray

Re: alloy barrels for 750 OIF 1971 - 02/01/16 5:17 pm

Thanks, Gavin. That's some nice stuff. He wears that slide on his pinkie!

Funny isn't it how the old time blues music talks to people the world over?

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 02/01/16 6:38 pm

I am a pinkie man too ( sounds weird!) its the elbow stuff I struggle with. I wish there was some video of Furry in his younger days, notice Bukka White at the end stuffing the 1/2 bottle back in his pocket, brilliant. For me, blues is the source.
Posted By: Triless

Re: alloy barrels for 750 OIF 1971 - 02/01/16 7:17 pm

Great stuff, Gavin, and economical with clutch springs,as well as musical talent!
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 02/02/16 3:53 pm

Clutch strip down continues, alarmingly the thrust bearing in the pressure plate was ATF, two rollers fell out on strip down and the cage is burst. I found one roller in the drain pan and the other on the floor, reminding me of when I first got the bike , when I found all the rollers on the floor of the chaincase. new thrust bearing goes on the shopping list.
[Linked Image]

One of the spring cups had rotated and the dimple is not as proud as it should be.
All three clutch springs have settled, should be 46 mm free length , all between 40 - 42 mm as found, more shopping.
[Linked Image]
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 02/03/16 12:10 pm

You know that one line in the manual " remove clutch centre hub using the clutch centre extractor"

Its always the short sentences that kick my derriere.
dug out my clutch centre extractors , a borrowed one ( which didnt fit , natch), one already wrecked one and one new one I didnt even know I had. Tried the new one, of course it failed as well, these things are as much use as a chocolate tea pot. If you can get one of these to work then your clutch centre isnt on properly.

Decided to go old school, dug out the home made self gripping 2 leg puller which has always worked in the past , set up the blow torch and while the hub was heating i spent an amusing 1/2 hour searching for the one roller which had made a bid for freedom on the floor. After sweeping, lying prone to look along the floor , sweeping with magnets , cursing roundly , drinking tea and cursing some more I found it , 20 rollers in the bag, ya beauty.
Checked the hub temp, 160 C, room now full of hot hydro carbon smell, me getting sweaty, fitted the puller , cranked it up tight , skelped the shaft , no joy.
Out to the shed for a pipe to use as a lever, bent the tommy bar on the puller , straightened it again, chap chap, , no joy, adjusted the tommy bar for a balanced drive with a pipe on each end , a few newtons more and Bang, the hellish thing was off . i hate doing this and it will be the last time, the new clutch centre sits on splines , HURRAY!. SWMBO , came in thinking I had injured my self. The Joy of getting the clutch centre off is almost as intense as the first start after a rebuild.
I did a little dance , whooped a bit and celebrated with a few lung fulls of paint thinners ( OK I painted the coil bracket ) same effect though.

Heat and barbarity , the last time. Ever.

[Linked Image]

Stripped the clutch down, hub and drum pretty fresh , light scalloping on the drum but still useable, thrust washer looks goosed, Im pretty sure one side was coppery when it went in, not any more, judging from the tailings in the oil pan its an ex thrust washer. more shopping.
Will post pics of this later , running out of time today.
Chain tensioner has the usual grooves but will last a few more K miles.
Stator lead grommet has also passed its use by date, more shopping,

DAWBED, ( Do a Wee Bit Every Day) , progress , but slow.Gaining momentum as the days brighten.
Posted By: Ger B

Re: alloy barrels for 750 OIF 1971 - 02/03/16 2:08 pm

Its always the short sentences that kick my derriere.
As an author of technical documentation I can say with authority bred by experience: you are correct.

The sentence is too short. It should have been:

Remove the clutch centre hub using the correct clutch centre extractor in the correct manner. grin
Posted By: TR6Ray

Re: alloy barrels for 750 OIF 1971 - 02/03/16 2:15 pm

Oooooh Ger. Please be careful. I think his blood pressure was just getting back down to normal.

Posted By: Allan Gill

Re: alloy barrels for 750 OIF 1971 - 02/03/16 7:27 pm

Id be checking that clutch centre for true/flat now if it's going back on, or do you have a different centre for the main shaft spline?

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 02/03/16 10:25 pm

Fear not that clutch centre is not going back on, the new 5 speed main shaft is splined not tapered and has a matching splined centre to fit. The puller Nick showed pics of on another thread is the correct tool, it pushes the centre off, I think that the standard puller has no chance, on my old centre it only engages about 3 threads , the puller is soft and the threads pull out , I have tried 3 now all from different sources , not one has managed.
Shock blows were used , I dont rely on puller pressure alone, however there is a difference between a shock blow and beating the shaft out of the timing side, I try to avoid that.
The nut was torqued to book figures with an accurate wrench, the tapers are clean and gripped well , maybe with more engagement the stock puller might work, YMMV.

Was the thrust washer plain steel both sides? Its not the original but I cant recall whether the replacement had a copper side or not, who knows? The current worn item has a definite wear ridge all round the OD, no spec in my 71 manual for thickness? This is quite a fast wearing part, its done less than 10K miles., not helped by slipping the clutch every getaway when using the high 1st CR box.
Posted By: JER.Hill

Re: alloy barrels for 750 OIF 1971 - 02/04/16 2:58 am

Hi Gavin

The method you used or Nick's puller are fine for the later three spring clutches. The early four spring clutches had a different arrangement where the centre was bolted into the chain wheel and the bolts were at the back, just to make it more difficult.
For these I'd suggest buy the standard puller and before using it heat it up to cherry red and drop it into case harding material, this may help! But your combination of load, heat and shock are the way to go.


Posted By: Mark Parker

Re: alloy barrels for 750 OIF 1971 - 02/04/16 3:42 am

I use bearing mount type Loctite on the taper, and it pops off easily with a little heat. The proper centre puller doesn't quite fit because I had to shorten the part of the hub where it screws in so it would work with the 4 spring centre I use.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 02/04/16 12:54 pm

Pics of clutch parts and new bearing plate

Clutch hub
[Linked Image]

[Linked Image]

Plate stack outer tangs

[Linked Image]

inner tangs

[Linked Image]

trial fit of bearing plate

[Linked Image]

mounting surface

[Linked Image]

Good news, plate tangs are not burred, light scalloping will dress up with a file. Gearbox sprocket not hooked! Plates show little wear , plain steels not polished and still showing machining marks
Bad news, the bearing plate fits too easily, in any of the six positions, the desired grip from the mounting flange just isnt there,as it is it would be held by screws alone, not what the doctor ordered, ideas?
The flange pic shows a machined recess, this is not deep 1- 2mm inconsistently all round and does not offer any options for a tight fit as is.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 02/04/16 1:06 pm

Sitting cogitating, ruminating, and pondering. Im thinking a ring of filler weld round the flange OD , then boring to suit the plate OD with an interference fit.
Possibly if the welding was done in short diametrical opposites distortion could be minimised, the boring would need to be from a fly cutter on a mandrel sized to the main shaft.
The flange area sits down in a cast in well, easy to see in the pic, the machined area is bound by what would be best described as a light casting flashing.
Posted By: TR6Ray

Re: alloy barrels for 750 OIF 1971 - 02/04/16 1:59 pm


I don't see how that gains you anything you don't already have, and the chance of disaster with that plan is great. How much side load do you anticipate for those bolts anyway? Whatever shear force there may be is already spread over the cross sectional area of the six bolts -- bolts you are planning to enlarge anyway. The only side loading would be from the bearing not being on center? Or maybe you are considering doing the weld & fly-cut to keep the bearing plate on center? How do you know it is on center to begin with?

I don't know the answer, but I don't think you're on the right track. I'll be interested to see what some of the engineer types on here think.

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 02/04/16 2:27 pm

On a very different scale I am familiar with what happens to bearing housings that are inadequately supported radially.
In the power station the 100 MW turbine bearing is the last one on the machine shaft, over 20 years I witnessed continuous slackening , of this bearing housing, each time the locating dowels which took the radial loads were reamed out and up sized , eventually the plot stabilized once the dowels were increased from approx 3/4 diameter to 1.5 inches, its standard practice on these large machines to leave clearance round housing fasteners and rely on separate dowels which are only drilled and fitted after final housing alignment. As discussed before this probably isnt a practical idea here. Nick And John both have previous experience and they both recommend a tight fitting outer collar for the bearing plate, perhaps on earlier castings there is more meat in this area.

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 5 speed gears - 02/04/16 2:29 pm

Originally Posted by NickL
I tapped the existing holes 5mm.
I ran a 520 chain on the racer so i could get 1/2 nuts on a few of them but they weren't required.
The plate should be a very snug fit and need the case warming to fit it.
On another case where a previous plate had been fitted i had to re-drill and tap the holes for 6mm
as 2 or 3 screws didn't line up properly and were 'cocked'.
If the plate is lined up and seated in the case properly with the case/plate taking the load, they are good. If the plate is loose and you are relying on the screws, they will come out.
SRM used to weld the plates in but that's a pain for anything other than racing.
I used a drop of green locktite which meant warming the screws with a small blowtorch to remove them.
Posted By: TR6Ray

Re: alloy barrels for 750 OIF 1971 5 speed gears - 02/04/16 2:41 pm

Okay, I remember reading that now. So, would you pull the engine to do the welding / fly-cutting? Maybe split the cases too?

Posted By: edunham

Re: alloy barrels for 750 OIF 1971 - 02/04/16 2:46 pm

What if you drilled and tapped a number of holes around the edges of the new plate-1/2 into the new plate and 1/2 into the casing? The additional bolts screwed into the holes would pinch the new plate without all the machining that would be required for what you are proposing.

Ed from NJ
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 02/04/16 3:01 pm

Hi Ed , thats an option, a cunning plan even, Ive chatted to John. Once the motor is out and split he is going to visit and we will come up with something. The welding seems a bit drastic, I was just thinking out loud.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 02/05/16 4:40 pm

John called today,it seems like my motor is particularly unusual, all others have needed material removed, as Nick suggests , a special oversize plate will be made to suit.
I must confess to getting the wrong end of the stick, the part of the plate which is supposed to be a tight fit is the boss which protrudes on the GB sprocket side, this is supposed to be a tight fit against the ID of the casing flange in the toothed zone. John reckons this may have been machined out at some point in the bikes past history, Oh well, these things are sent to try us.

Strip down, good news, the swinging arm spindle came free with a casual dunt from the soft face hammer. Its not off yet, but its a relief to know that extreme force is not needed.
H bars off and forks to follow soon. Battery carrier dropped off at Ali's to have two studs welded to the bottom side for mounting the reg rec. Currently looking at possible relay mounts for lights behind the head stock , and a main relay to be mounted using the old zener diode hole in the airbox.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 02/09/16 8:12 am

Work ethic index now stepped up from "Do a wee bit every day " to " An hour in the morning is worth two in the afternoon."

Fork strip in progress.
I leave the stanchions in the yokes ( 3 x trees for you colonials) , take one top nut off, drain the opposite leg, then visa versa. The oil came out a baby scoor caramel , but no internal corrosion or swarf. I do change fork oil fairly regularly at least every blue moon.

Leaving the legs in place I undo the damper rods with an allen key and light pressure against the spring to stop rotation, works for me, no special tools needed.

Dampers came out, all looks good, o rings still in good condition.
One surprise in the LH slider there was a crushed dowty seal, this must have been in since the last rebuild, it has dunted the damper rod retainer alloy nut a bit , so full travel is being used!.
No damage though.
Springs are short, book free length 503 mm, as found around 485 mm, new progressives going in as a replacement.

The stanchions are pretty stuck in the lower yokes , so far one has budged about 6 mm after a bash on the top nut, heat , wedges and violence to follow.
The stanchions are the reason for the strip, large areas of plating are absent on the thrust areas.
no leaks though.

Once the front end is off I will remove the last of the engine mounts , oil pipes, then throw the bike on its primary side, give it a shogle and let gravity do its thing.

The battery carrier , reg rec mount is done. Rubber bits ordered from North West MCs ( the LBS).

Off to a boat yard today to pick up old Zinc anodes, the bulk of the fasteners will be re-plated at home using Low tech chemistry, Zinc anode, , Sodium Carbonate ( washing soda ) and vinegar electrolyte. With brick cleaner HCl as a pickle before plating. power source will be the bike battery ( on charger) with lamps in series for current control if needed.
Not done this before , but a few hours on Youtube makes it look pretty easy.
Before pickling all parts will be de-rusted using electrolysis.
Rear Axle , chain adjusters , mudguard brackets, rear brake return spring and op lever, fork fasteners all getting the treatment.

Minimum price for a bunch of parts Zinc plating is 35 quid plus postage. Investment in plating materials so far , o, all the stuff was lying around.
Pics to follow.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 02/10/16 10:10 am

Fork strip down pics, releasing the damper rod
[Linked Image]

Stanchion end plug easy to unscrew with stanchion still mounted and some light spring pressure, no special tool required.
[Linked Image]

The zinc anode donor , a working prawn creeler at Barcaldine boat yard.
[Linked Image]

Once I get the fork tapers free I remove the top yoke, this blurry picture shows the soft hammer and wedges used to free the lower yoke, it took one hundred and sixteen blows ( I counted them) with the hammer to free the stanchion, this was not vice mounted I hold the yoke in my left hand for exercise value. Using a vise will need fewer blows, damage the yoke somehow, , and you will miss out on the exercise..
[Linked Image]

Original factory taper rollers , rubber seal over top inner
[Linked Image]

Damper rod piston, o ring, shuttle valve rebound spring

[Linked Image]

Fork strip tools, AF socket ringers, Allen key, wedges, soft hammer and old Snail brand spanner filed out for top nuts.

A true hero of the revolution
[Linked Image]
[Linked Image]
Spanner porn, shorty AF britool staggered ringers, 7/16 "x 1/2 ". and 9/16 "x 3/8", the rubber tape helps me find it in the melee.
[Linked Image]

My favorite 3/8 th drive shorty with knuckle.
[Linked Image]

Top head race
[Linked Image]
Bottom race, some water marks here from condensation, but no obvious wear, felt ok, but I will change this now I am aware of it.
[Linked Image]
[Linked Image]

Peeling chrome on the thrust faces of a stanchion,
[Linked Image]

Nothing too unexpected here,
apart from
[Linked Image], a misfitted and crushed dowty seal fitted by the dumb current owner, its had an interesting life from the look of it. I have new seals and stanchions on the shelf, kommando has a "cunning plan" for damper improvements, i am to be a guinea pig, so new springs and damper bits are on hold.

Yokes to be painted, new rubber mounts maybe.
Posted By: kurt fischer

Re: alloy barrels for 750 OIF 1971 - 02/10/16 12:15 pm

Thanks, Gavin, and it's good to be kind to the yokes, they are very malleable, I have found.

Standing by for the "cunning plan" ... my Bitsa Triumph has a '71 front end which could use some improvement(s).
Posted By: kommando

Re: alloy barrels for 750 OIF 1971 - 02/10/16 3:01 pm

The cunning plan involves using adapted fork internals from a modern sports bike, this should give digressive damping eg shim cartridge, the valve will run inside the stanchion like the originals but with a Bronze impregnated PTFE ring on the OD to try to cure the stiction issue the O ring gives.

Posted By: TR6Ray

Re: alloy barrels for 750 OIF 1971 - 02/10/16 5:55 pm

As long as there's no computer software involved . . . eek !
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 02/14/16 5:37 pm

Ive been a bit busier.
An ex friend borrowed my 1.5 inch AF deep socket , which I need to remove the gearbox sprocket. His status is downgraded from "welcome visitor" to "Scum of the Earth", if I dont get this soon there will be hell to pay.
because of this I have been progressing other work.

Fork oil seal removal.
[Linked Image]
That hooky thing is pretty handy.
[Linked Image]

Where the wear is , galling from chrome flaking, not good, I may get this bored out to 50 mm depth and re bushed , new sliders are 145.
[Linked Image]

MZ yoke LHS , BSA RHS, note stem differences and increased offset . MZ stuff is tuff.

[Linked Image][Linked Image]

Top yokes
[Linked Image]

The yokes have had electrolysis know , all the rust is gone, particularly from the bored stanchion clamp areas.

What used to be the loom outer woven sleeve, an oily tinder pile.
[Linked Image]
Redundant points wire. I separated the redundant from the needed for educations sake. This was a stock early T140 loom, the points to coil wires are about 6 feet long!

[Linked Image]
redundant indicator wires
[Linked Image]

The working part of the loom
[Linked Image]
[Linked Image]

Used this rotary file to do mischief to the side panels.
These panels never fitted correctly, they say hello to the coil bracket and the frame and the battery carrier. The RHS panel was 2 mm deeper than the LHS panel. Over the years they have rubbed away at each other. No more.
[Linked Image]
Cut away at coil carrier/ battery carrier meeting point.
[Linked Image]
Clearance scallop in side panel and radiused coil carrier.
[Linked Image]
[Linked Image]

I reckon with 71 being the first year of OIF production , there were a few things that worked in the drawing office but not in reality. The fit of the side panels is a great example. I thought about the repair for quite a bit before scalloping the panels, an alternative would have been to cut away the rolled edge of the coil bracket which would have lost its stiffness, and the frame tab which mounts to the coil bracket would have needed surgery as well, perhaps losing some strength, my feelings are that the side panel mod was the least worst solution. There is a slotted mount in the side panel to allow adjustment and I am still at the extreme end of this range , to put it mid slot would mean taking another 3 mm off the side panel thats how far out they are.
My parts are as fitted by the factory, but you would think they were badly miss matched spares.
The coil carrier has a central cut out for the battery strap hook, however the strap hook is not central, poor show chaps.. .
Posted By: Andy Higham

Re: alloy barrels for 750 OIF 1971 - 02/14/16 6:01 pm

There were a good few mistakes made at "slumberglades hall", the worst being the outragously high seat hight of OIF bikes (especially if you are only 5'6")
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 02/14/16 6:09 pm

I cant use caustic on these, after a 1/2 tin of Nitromors, about 6 applications , still not quite there.
Many 71 model BSA owners fitted with these side panels went on to develop successful careers in gynecology, inspired by the hands on training given by the side panel mounting system. The panel inners are getting a 5/16 UNF helicoil and 1.75 inch long SHC so that they will become less challenging to fit.
[Linked Image]

Ive been looking into paint for brushing " coach painting", Tekaloid and at the POR 15.

The Tekaloid needs primer/ etcher/ undercoat then top finish. I have used this sort of stuff before and it gives good results. Its UK made as well.

The POR 15 needs, some sort of etch , then chemical stabilisation, then the top coat. Not so much Paint Over Rust as Paint over chemically stabilised Fe O3 , cost wise. both work out around the same.

The new loom will have 4 relays, One dip, one main beam, one all lights ( controlled by lamp bucket switch ), one main relay ( controlled by ignition switch).
I have been studying Stuarts wiring posts and I am going with 5 interconnecting blade fuses.
Two gauges of wire, heavy for the relays and light for controls. The control colours will be the same as the power colours and stick pretty much to the stock loom colours..
The boyer is moving to the RHS side panel , on sticky velcro. The reg rec is going to hang from two new studs on the bottom of the battery carrier. The main relay is going at the old zener mount. The main lights relay to the LHS Side panel. Main beam 5 blade relay ( extra room for spot lights), under the headstock on the old reflector bracket at the gusset.and a dip micro relay in the lamp bucket.
This gives a pretty simple 5 wire main spine to the loom. A red earth, white heavy gauge ( to main beam/ spot relay) , white light gauge control supply, Heavy blue gauge to dip relay (from Main Light relay), Light blue gauge control, from light switch to Main light relay. ,
The boyer is not relay fed, but will benefit from having 12 feet less wire and 2 less connectors.
I made 18 drawings? to get this far.
A possible option is to use the RHS indicator switch as the main / pilot switch and replace the flat back lamp with a cockpit fairing . Still swithering.

Maybe overkill, I like relays though, Clifford and Snell .

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 02/14/16 7:17 pm

Hi Andy
Not just the height, the width of the front section of the stock seat stops you getting your legs down easily, my seat is a narrower ( Triumph) style and is a bit easier to get on with. Once your rolling its fine.
part of the fork mods is to lower the front end, going down 50 mm from 6 and a half inch to 4 and a half inch fork travel. Stock springs are 25 lb/ inch. 6.5 x 25 = 169.
169/ 4.5 = 37.5 lb/inch for new shorter springs to give the same overall resistance over a reduced travel..
A secondary useful benefit is the sliders will have more bearing surface in play at all times.
Supposedly damper rod forks were softly sprung to compensate for the poor inherent high speed damping.
The new damping should allow slightly stiffer springing. I am not sure if my maths is correct, have at it you suspension boffins..

With a lower front end the centre stand will be way too long. Centre stand pruning goes on the job list.
Posted By: Adam M.

Re: alloy barrels for 750 OIF 1971 - 02/15/16 11:10 am

Hi Gavin,
About POR 15, I used it only as a tank inner coat but I was impressed with what was spilled on my work table. Impossible to remove with anything I had in my disposal back than.
You should talk to Tridentman about frame brush painting with it, or dig out his old posts.
I'm not sure he used all the products for preparing a tank before painting.
He claimed a look of the brushed paint on the frame was very good.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 02/16/16 12:49 pm

Thanks Adam, Ive been through T mans posts, very illuminating.
Working at the airbox currently.

The "loaned " socket turned up , , sprocket nut came off easily. Before I take the motor out I am going to finish fitting the guts of the electrics and airbox. Also stripping air filter covers . lots going on. Exciting parcels arriving.
I looked at images of T120 side panels, the top edge is scalloped considerably on some of them, took a while for the factory to catch on.
Posted By: Lannis

Re: alloy barrels for 750 OIF 1971 - 02/16/16 2:18 pm

Originally Posted by gavin eisler

The "loaned " socket turned up ,

So now is the "ex-friend" a "friend" again, or was it something else .... ?

These little details are important to us when we follow your project ....

Posted By: kevin roberts

Re: alloy barrels for 750 OIF 1971 - 02/16/16 4:56 pm

i have fairies in my shop that delight in hiding tools and such until i give up and go buy another, and then immediately restore the missing item in such an obvious place that i know it was impossible to have missed it before.

as a result i have two chain breakers, three hacksaws, and five grease guns, to name just the first ones that come to mind.

the greaseguns were a massive triumph for the little people. they had me dancing in fury over and over every time i was forced to go buy another one.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 02/16/16 8:44 pm

The Loaned Inch and half AF Socket .
I FB-d my friend KH regarding the dearth of 1.5 " AF sockets in my toolbox.
( The "welcome visitor " previously mentioned);
who I recalled was restoring a mini ( BALL JOINTS ) at the time of the "lend" several years past,..... about 3 weeks ago,
knowing at the time I would need it
( the inch and half socket, deep style)
for the strip down to come.

I suggested it was time to get it back.,

a couple of weeks went past,

his freezer broke down,

. I FBd him , intimating that this might be Karma for poor tool return rate,

He said, "I will get my son Ross to find it for you ".

Ross is a chef in the local hotel. Both good guys , great singing voices.

Nothing happens.

It gets to the point that Ive started messing with side panels when the motor should be out and
I go

,"come on!,FFS wheres my , swearword , socket",

By this tune I ve contacted the local tools place and figured the cost/ time of a replacement. 20 and a trip to Oban.

back on FB. Contact KH,

" you owe me twenty quid or the socket, sort it out."
Being Scottish,And frae Ayrshire, and realising he has gone beyond the Pail. , KH instantly sends Ross to my door with 20 quid.
Ross gies me the dosh. Then sees the bike, I explain the problem, with the GEAR BOX sprocket.
Ross says " Is that the bike yer ayeways cuttin boot on "
an I say " Aye... ye ken, the noisy wan " .
and he goes " Haud on ameenit ". and nips aff.

Nips back to his gaff and re appears with the very thing.

Happy Days

.I gie him the twenty quid back and all ends well.

The gearbox sprocket nut comes off two minutes later.
The sun came out,
Status re appraisal. Welcome, but, not to be trusted with tools.
the end.
Life in a Scot's sitting room, Vol 6 part 3. By Ardmore.
Posted By: Lannis

Re: alloy barrels for 750 OIF 1971 - 02/16/16 11:16 pm

Wow! That's a pretty good story, I thought I was reading Robert Louis Stevenson there for a meenit ... !


Posted By: TR6Ray

Re: alloy barrels for 750 OIF 1971 - 02/16/16 11:29 pm

That's a good piece of writing, Gavin! :bigt

{Edit} Lannis, we posted at the same time. I have to say your post bested mine and made me chuckle.

Posted By: kommando

Re: alloy barrels for 750 OIF 1971 - 02/17/16 6:50 am

I have lived in Ayrshire for 25 years, only ever met one Ken but he gets mentioned in every conversion as 'yer ken' wink
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 02/17/16 8:06 am

"Ken whit eh mean?" = " Do you have the knowledge of my intentions?"
Still common parlance, To have the Ken. Old language, very economic in its lack of verbosity..
Glad you enjoyed it.

off to a flying start with braithwaites coffee beans
[Linked Image]
You cant smell it , what a shame
[Linked Image]
Lately I have been mostly torturing the air box back into shape. While the electrolyte gently bleeds the rust off the hardware and the Nitromors does its horrible stuff.

Trial offering the filter covers to the bare box, an obvious rock could not be ignored.

The air box is quite a sturdy construction but previous drops onto the side had caved in the trailing edges about 4 mm when checked against the bench. This wasnt helping the side panel / bracketry interface much either.The LHS inner box top flange had cracked,

[Linked Image]
now that its flat a small weld should keep it all from opening up again. Even with this corrected the side panels wouldnt fit correctly so my scalloping wasnt in vain.

I placed the bend area over a small chisel to act as a fulcrum , by heating till the paint burned off and squeezing the clamps I was able to push all the distortion back out,

[Linked Image]
this took a while, repeatedly heating and applying pressure.
[Linked Image]
Both sides needed correction. While I was at it I fitted 5/16 " UNF thread inserts to the air box inner web so fitting the filter covers will be easier,

[Linked Image]
no more 3 handed gynecology.Theres just enough meat on the casting for the insert tap to get a bite, no drilling

In one of the exciting parcels I found the usual polystyrene packers, hmmm, I wonder what the airbox volume is ?

Using the poly packers, I taped over the air box circular manifold holes, loose fitted the filter covers and filled the plenum chamber with the packers, this was crude, rice would have been more accurate, but it gave me a rough idea, turns out its about 3 and a half pints or approx 2 litres.
Thats around three time the swept volume of the motor and up there with current thinking on air box plenum design. As an engineering item its very well made, the castings are die cast and quite fine in detail.
[Linked Image] Its a pity the rest of the panels hadnt been so well thought out.Stock is trick in my book, this has to be better for engine breathing than the chrome pie tin filters on shear volume alone.

Using the cordless , with a wee brass brush for the 18 nooks and 32 crannies. It has a useful stop thinking / stop moving function.
[Linked Image]

And another thing while I look at the air box, each side has two rectangular, inlet ports, the filters supplied come with one port blanked off,

[Linked Image]
so the air flow is half what it could potentially be. An obvious thought occurred, since air flow gives HP why is this blanked? Is it a noise thing? does opening all the passages up mess with the air speeds? Does Any one know? or even care!

I have all the makings of a new loom now, theres piles of snaky coils every where so before the motor comes out I will finish the bulk of the loom to get this out of the way.

Assorted fork sliders
T140 disc mount no rib.
[Linked Image]

Conical hub style , ribbed for stiffness, ooh err, and tank bracket.
[Linked Image]
Posted By: Ger B

Re: alloy barrels for 750 OIF 1971 - 02/17/16 11:55 am

Old language, very economic in its lack of verbosity..

I like it.
I have not lived in my birth town (a fishermans port in Friesland) for forty five years,
but when I'm there with my brother I'm in the local language withing five seconds... OK, maybe six.
Not standard official Fries, but really local.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 02/17/16 1:32 pm

Hi Ger , I visited Schiermonikoog in friesland once upon a time, lovely place.

The good welder is busy, set up for SS exclusively . Plan B ,lumiweld, I have a stick somewhere.

Final fit of scalloped side panels, a clear 1/8th all round and no longer nipped at the end of the mounting slots, full engagement.
[Linked Image][Linked Image]

More air box shots
[Linked Image][Linked Image].

Next, wiring, painting , ritual humiliation.
Posted By: Ger B

Re: alloy barrels for 750 OIF 1971 - 02/17/16 2:14 pm


I was at school on Terschelling, last year of my study for marine engineer.
I think Schiermonnikook is a similar island, although the locals all claim their island is exclusive and absolutely different from the others.

I'm looking forward to see how you do with the wiring.
My A65T is on the table for a wiring job but my shoulder does not allow me to get it done yet.
Posted By: DMadigan

Re: alloy barrels for 750 OIF 1971 - 02/17/16 6:44 pm

Those look like later model filters. My '71 650 had no plate on the filters. It may have been the T140 added the plate and a snorkel piece in the hole pointing to the inside of the frame to reduce noise.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 02/17/16 9:23 pm

Ah, thanks Dave, , I will cut out the blanking plates. I quite often buy T140 bits knowing they should fit.
Picked up some Brick /path cleaner today for a pre- plating pickle.

Posted By: pushrod tom

Re: alloy barrels for 750 OIF 1971 - 02/18/16 10:15 am

Gavin, Thanks for the stories. Helps pass the effing winter! PRT
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 02/19/16 8:15 pm

Mair Winter tales.
How I got into this mess.

Black Eck.
When I was a wee boy in the 60s a certain bike would appear in my street, on a Friday night just after tea time.

The rider was a big guy dressed in black leathers, black helmet , black A65 Thunderbolt with valanced mudguards. The speedo went up to 100 mph, my mums car only went up to 85 mph,she would hit 55 max if she was angry, this was a Fast, Dangerous, Motorbike.
He would park at the end of my street under the street light across from the phone box and chap on all the doors of the people that did the football pools.
Eck was a money collector.
He put the cash in an old canvas gas mask bag slung over his shoulders. The pools coupons were strips of card with red boxes and various coloured hopeful X scars scattered across them.. To me he was almost a monster, but when he caught me keekin at his bike he wisnae too bad.

"De ye like it?"
"Aye , it sounds braw"

I would hang around till he kicked it back up and roared off , that made my Friday night.

Black Eck had other acquaintances at the smiddy. ( If you land at Glasgow Airport ( famous for its terrosist repellent ability) , that was made in the Wellbank smiddy)

One Ball Pete.
What a cheery guy. On the bright side a roofer who has slid down the side of a building onto the steel girder and still has one ball left has to be optimistic,

Farfar Jock.
Watched him do the ports on a B25 for his boy.

Bill Dalziel. A man who lived in cellulose thinners fumes and who could fix anything.

Eck the Bleck ( not the same guy) "de ye mean Black Eck" ," Naw !! Eck the bleck., a squat man with heavy black spiked eyebrows who was a living neanderthal.He was constantly covered in grinding splatter, and habitually wore a darkened leather apron.

these were the sort of guys who once had your bikes.
if you were lucky. They tore them down, put the best bits on that were available , did them up and sold them on.
If you pick up an old bike its worth bearing this in mind.

On a more pertinent note.
Wiring continues, relays maybe in the final location and of course, I forgot some essential components. Piggy back terminals, battery commodious rings and fuses with LEDs that light up when they blow!, who would have thought?
Stuarts tip for the stacking fuses is a blinder , they are very neat.

Posted By: Ger B

Re: alloy barrels for 750 OIF 1971 - 02/20/16 8:59 am

cut out the blanking plates

[Linked Image]

Gavin, if you mean you want to cut out the plate inside the filter elements, there is no technical reason to do so.
Mine have had the plates for as long as I have the bike.
Just remember to install the element with the plate on the inside, closest to the battery so to speak.
So the air enters the element via the hole, passes the element from the inside out into the plenum where the carburettor sniffs it up.
Only this morning, making the pics, I realised after eleven years: I've got two different elements. sick
One with a square hole, one with a circular hole.
But no reason to change a winning team I guess. grin
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 02/20/16 10:26 am

thanks Ger. I have the sort with the rectangular hole. I will leave well alone.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 02/22/16 2:58 pm

While I wait for more wiring stuff I have been lightening the motor for removal.
The day starts with Stornoway Black Pudding.
[Linked Image]
A couple of items from a crashed WW2 bomber. Filter and "Tecalemit" lubrication badge.
[Linked Image]

Some relays and interconnecting fuses beside a neolithic gaming stone found in Orkney.

[Linked Image]

Crimping tool and stripping pliers in open jawed combat.

[Linked Image]

Battery carrier with new reg/rec mounts.

[Linked Image]

Tach drive , oil pressure switch, boyer guts , all pulled prior to engine removal.
[Linked Image]
1/16th AF allen key for grub screw removal
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The troublesome socket and a whole set of AF and metric allen keys.
[Linked Image]

Drilled and thinned timing gears, iron oil pump. Gasket intact , points oil seal leaking a bit,
idler gear bushes are pretty sloppy.
[Linked Image]

Crank end feed quill, feed NRV spring, O ring in cover joint as part of end feed oilway.
[Linked Image]

On the trail of overnight wet sumping , oil pump gasket, not guilty.
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The NRV Ball seat was rubbish, under a times ten microscope this is the obvious fault, its like a wee ploughed field where the NRV ball seats
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Close up using camera on macro shooting through a LED ring lit magnifying glass , came out better than I hoped.
[Linked Image]

Gear cluster out, chain , sprocket off , engine oot the moarn. More pics later.

Pleased to have found the wet sumping smoking gun.


Posted By: Lannis

Re: alloy barrels for 750 OIF 1971 - 02/22/16 3:09 pm

Kind of like the "I Spy" kids books, interesting juxtaposition of various articles that are interesting in their own right.

We can never buy that combination of beef suet, onions, and pork blood that goes by "Black Pudding" - I love it but most people won't consider anything that specifically has "blood" in the ingredients list, even if blood is all in the rest of the meat they eat .... ? Pity, except for the opinion of one's cardiac doctor .... !

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 02/22/16 3:14 pm

Hi Lannis, Stornoway black pudding is the ne plus ultra of Pudding noir. Its officially a "superfood". Unusually SBP is made with sheeps blood ( I think ) , it tastes superior to almost every other UK blood sausage.
Although artisan Spanish "Murcilla" gives it a close run for the money.
The oddities were lying around, no particular reason for the pics.

No real surprises on stripdown, the motor and gearbox internals show little wear or carbon blackening so far. A wee groove where the index plunger runs against the cam plate, but nothing major.

I will lap the ball seat with some grinding paste then strip and clean the oil pump.
Posted By: Andy Higham

Re: alloy barrels for 750 OIF 1971 - 02/22/16 3:27 pm

I love black pudding, the next town to me Bury is the home of the black pudding.
A nice twist is black pudding with goats cheese, a match made in heaven
Posted By: Lannis

Re: alloy barrels for 750 OIF 1971 - 02/22/16 4:37 pm

Originally Posted by Andy Higham
I love black pudding, the next town to me Bury is the home of the black pudding.
A nice twist is black pudding with goats cheese, a match made in heaven

When my son and I were staying in Kirk Michael on the IOM for the Manx GP, there was a butcher shop up the street that (like many of these small High Street butcher shops) made all their own carnivorous treats.

One of the reasons I love the IOM is that its the only place I can get Manx Kippers, they don't export them, the exclusive barstewards, but on mornings we didn't have Kippers for breakfast we'd go see what the butcher had that day.

We got Cumberland sausages (well, they weren't really Cumberland sausages because this wasn't Cumberland but they were near as dammit) and Haggis and Black Puddings with sure enough sheep's blood, he said and it was all great. You just can't get that sort of thing within range of my house. I suppose butcher shops in big cities have it, but Central Virginia doesn't have those places .....

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 02/22/16 5:12 pm

Back to the job, note to self and other 71 owners, the rear engine plate 5/16 bolt only comes out with the motor and plate, refit loose to plate and motor BEFORE refitting the motor to frame.
Oil pipes off to access motor mount bolts, fit motor bolts BEFORE oil pipes.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 02/23/16 9:06 pm

Sadly the camera battery gave out when the motor was extracted.
A rare day of sunshine to lift the spirits.
With a bare frame and rear wheel still in place , I refitted the primary chaincase and the inner timing cover, removed all the engine mounts bar one.
laid the poor thing over onto a large cushion on the primary side, pulled the last , front mount then wrastled the frame off by picking up the seat rail. nae bother .
Motor now on skateboard for easy shuffling.

Frame getting cleaned over a barra , paraffin and steam.
[Linked Image]

Whats left of the side stand mount.
[Linked Image]

Previous repair to rear engine bracket to oil spine, weld done Duncan Muir many years ago. In one evening , rode in , rode out.

[Linked Image]

Swing arm pivot dollies/ bobbins whatever, corrosion marks mimicing greaseways in the bushes. thats condenstation for ye.
More shopping. Bushes and play is fine but I cant put those back.
[Linked Image]

Swing arm in rhe bucket for rust removal along with chain adjusters and stuff.
Found a replacement airbox on ebay for 15$ plus loads to deliver , but a bargains a bargain eh, also comes with airbox covers and rubbers so , spares for the future. luckily these things are deeply unfashionable.

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 03/04/16 5:30 am

Work ethic upgraded , " an hour in the morning is worth 2 in the afternoon" plus fresh ground coffee, plus burning midnight oil.

Frame repairs, 2 jobs done, captive air box nut and tank mount , check. Now at the smiddy for footrest mounts and side stand horror clean up.

Made some electric soup.
Recipe Zinc anodes. as many as you can fit in the bucket.
A clean plastic bucket
Sodium Carbonate ( washing soda) a couple of handfuls
Brew bucket heater belt.

Battery Charger on 6 V low charge.
Brass brushes.
Brick cleaner ( 10% HCl , in murkin , Muriatic acid ( how quaint))

Poor boy trolley
[Linked Image]

Zinc anodes from OB 597
[Linked Image]

Creating silent electric silver paint.
[Linked Image]

Assorted victims
[Linked Image]

Head off , nice joint.
[Linked Image]

Piston tops, note loose carbon.
[Linked Image][Linked Image]
Lovely matt grey 100% round rings.Bleck marks are carbon, this is pre cleanup.
[Linked Image]

Down the bores, so shiny.
[Linked Image]

Bore LHS , and rusty nuts ( now being de -rusted as I type)
[Linked Image]

Bore RHS
[Linked Image][Linked Image].

Off to see JH later today.
John asked me to watch for pushrod rub, none noted , all came out the way it went in, stock alloy pushrods.
Cases splitting today.
Posted By: Andy Higham

Re: alloy barrels for 750 OIF 1971 - 03/04/16 5:40 am

"Brick cleaner ( 10% HCl , in murkin , Muriatic acid ( how quaint))"
I thought a murkin was a "down below" wig
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 03/04/16 6:41 am

A Mirkin is a pubic wig, , a Murkin is a white settler on the other side of the pond. At least thats the way George Dubya pronounced it.
Posted By: Andy Higham

Re: alloy barrels for 750 OIF 1971 - 03/04/16 6:58 am

Ah! same sound different spelling
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 03/06/16 8:08 am

Picked up the repaired tank from John, new steady bracket mounts and fuel tap locations, cracks welded up.
I need to sweet talk the Appin pottery people into using there oven to anneal it.
[Linked Image]

Crank drive side main is very loose on the shaft, I can throw it on from across the room, note BOOM mark on crank at 4 o clock.
[Linked Image]

Sump strainer , first look in 16 years, there was one small snotter of Hylomar on it.
I dont disturb this every oil change, just the magnetic plug.
[Linked Image]

Cam shaft
[Linked Image]

That blob of brown atuff is epoxy, filling the primary chain tensioner pivot hole.
[Linked Image]

Underside of piston and gudgeon pin, no nastiness here.
[Linked Image]

A poor pic of replated axle parts
[Linked Image][Linked Image]

Lamp bracket and pinch bolts after plating
[Linked Image]

Stock cam gear LHS, lightened and thinned centre, 3 key way type RHS
[Linked Image][Linked Image][Linked Image]

Next, crank out and off to SRm to resleeve drive side, check balance and have the head refreshed.
Posted By: Allan Gill

Re: alloy barrels for 750 OIF 1971 - 03/06/16 3:55 pm

What cam are you running Gavin?
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 03/06/16 6:12 pm

Crank out,
[Linked Image]

The gear case already has had some relieving at the top of the cam plate swing.
[Linked Image]

Brewed this up from a couple of 3/8th high tensile bolts, crank pinion puller.
[Linked Image]

Puller in service.
[Linked Image]

The wear at the crank drive end is a must fix, I had fitted this with bearing fit , it did not work.
The crank end is oval by about 2 thou , it will be machined and sleeved to repair.

big ends are sound , but the little ends could be tighter, valve guides are suspect as a source of carbon on the piston tops.
I was sure I had a brass caged roller on the drive side, memory playing tricks , as found its a steel caged item. Mains are both fine.
While the crank and head are away ( balancing , machining and valve guides/seats. I will finish cycle parts tart up and figure out the 5 speed stuff.

most of the crappy work is done, blacked up some hardware using Baufix rattle cans from Lidls , the primer is really good.
looking into other electrolyte mixes, my water, vinegar, washing soda is working but slow.
I made some classic errors, too much current, dirty anodes, washing the good white stuff off the anodes, too many items at a time. Now the mix is plated out a bit it works a little faster, carding out ( removal , cleaning with steel wool and rep dipping) is an essential part of the process.The plating is not bright , or at all granular , quite a fine lead like finish, I havent tried polishing it yet, just rubbed up with a brass brush and wire wool.
Other possibilities.
Vinegar , epsom salts, zinc sulphate ( to pre load ) sugar ( to brighten .
or , using all safe E numbers, Oxalic acid, Tri Sodium Phosphate, Ammonium Sulphate.
I may try another mix.

Looking at the timed breather system, the cam shaft is a real restriction, its hard to conceive of 750 cc of air moving through the internal drilling at 6,000 rpms. Considering the front engine mount bulge as a more direct higher area passage. Discussing this,while I was visiting John, he pointed out a little bruising on the case centre joint at the 5 oclock position, where the case must have taken a knock at some point , this has been dressed flat with a large file registered on the rest of the face. Other than this the cases are sound, it didnt leak before .
The bike is almost as far apart as it gets , some sub assemblies are still intact and a few items ( Clocks, chain adjusters, yoke pinch bolts and rear axle/ brake hardware)are finished , so nearly over the strip down stage, not looking forward to stripping the frame, that old black stuff is tough. The rear engine plates have the toughest paint so far.

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 03/06/16 9:22 pm

Spitfire cam, its in fair condition. Replaced about 16 years ago. The idler gear bushes are pretty worn, these will be replaced. Leaving it as found, crank is getting balanced and refreshed, guides and seats , new springs. That will do, I have some 32 mm carbs lying around which I may try.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 03/08/16 9:38 am

Examining the pressure relief valve, as found the filter strainer and retaining washer were separated from the body and sitting loose in the well of the cavity! They are only crimped in.

The design relies on 3 threads worth of sealing between the HP chamber and the spring/ piston chamber. I measured up the relief hole in the casings and the v/v , they match OK, good enough .
[Linked Image][Linked Image]

Valve body with bleed off port at three oclock.
[Linked Image]

Relief passage to return line
[Linked Image]

left tp right, valve body with pointer in blow off port, piston , spring.
[Linked Image]
However the female threads that the body of the valve screws into are hardly an effective seal. On clean up I found evidence of lint/ gasket compound lodged in the threads, presumably pushed into the leakage paths.
This area is getting a careful application of thread sealer inboard of the relief passage hole on re -assembly. I will re crimp the strainer, the piston and valve body are fine, re- plating the hex dome for cosmetics. No I am not buying an SRM valve , this one will do fine.

A look at the cam each lobe in turn, this was a new item, Spitfire profile 16 years ago .
[Linked Image][Linked Image]

Cam followers, drilled for extra speed ! natch. Stock radius.
[Linked Image][Linked Image][Linked Image]

Old 4 speed cam plate showing polishing at selector fork tracks.
[Linked Image]

Typical index plunger wear ( this is with 2 turns cut from the stock spring) it will usually be a lot more gouged if the stock length spring is used.
[Linked Image]

Now the fun stuff, trial fit of 5 speed lay shaft.
The area around the spot faced zone marked by the dividers needs to go to clearance the large end ( 5th ?) gear.
[Linked Image]

thrust washers, Johns lovely bronze item on right, stock on left.
[Linked Image]

At the opposite end , the zone at the pointer needs relived to clear the 1st gear

[Linked Image]

Priority work, get the bits off to SRM, next installment, heavy postage bills. Almost finished re - plating top end fasteners, looking braw. Using up all the old black paint that was lying around, 2 cans of primer down , repainted the rear brake plate and speedo drive with some old silver paint that was art the back of the shed. No pics, watching paint dry is not exciting.

Posted By: Adam M.

Re: alloy barrels for 750 OIF 1971 - 03/08/16 1:11 pm

Interesting as always Gavin, your use of English language makes me always smile when reading your stories.
Very nice pistons, no blow by at all, bores look much too shiny for my liking, but apparently everything works together splendidly. I'm quite sure all this oil on the piston's tops gets there through the guides. I'm very happy with higher quality valves / guides combo than run of the mill stuff sold by our dealers, but I'm not sure you want to spend extra money after heavy spending for cylinder, pistons and 5 speed gearbox.
I'm not going to the dark side completely, decided to build a special from my parts left after selling my BSA as original 70 Thunderbolt.
Still don't know how I'll like my Trident after light and flickable BSA, never even tried one.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 03/08/16 2:10 pm

Hi Adam
Im happy to get the head refreshed, maybe even have larger inlet valves fitted, in for a penny, in for a pound as they say.
I havent spend much on refinishing, plating costs so far , 10, for brick cleaner , still got 9 quids worth left. Paint costs, close to nothing , using up old stock. Although I am down 100 gloves, started a fresh box today! I have the hardest working battery charger in Argyll.
Every thing bar Alloy stuff and the frame has had a visit to the brown soup bucket for de rusting. Its silent and works 24 / 7, After that if its getting plated, a trip to the wire wheel, then pickling for 20 minutes, then either into the Zinc soup or , stored in a jar of thinners to prevent rusting. Welding so far 50 but more to come. I am not spending money on wheels, although cosmetically the hubs are tatty they can wait for another year.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 03/09/16 7:17 pm

No fresh pics today but work goes on, found the dremel, and the verniers ( 3 sets!), hurray!

This pic shows an interesting feature.
[Linked Image]

The arrow is pointing at the lay shaft thrust washer wear zone, this is why the lay shaft endfloat opens up with age.

Crankshaft is almost crated up, spent a wasted few hours , got a call from an old mate, "if you want a couple of cheap old bikes get yersel uptae Aviemore, theres two bikes, 70 s Yamahas 125 and 350 I think, on a shelf 15 feet up ina pub , they have to be gone by lunchtime tomorrow, yours if ye want them". Phoned around , by the time I had organised a Genie super lift and a van, the cheap bikes were going to be about 400 quid. Then I got the pics, , a 4 stroke Yamaha 125 ( complete) and a rolling chassis powder coated red single 350 Yammy with no tin wear. My visions of a 70s RD 350 and a DT125 went up in smoke. Not interested, 3 hours gone I will never get back. Passed on the info to the lift hire folk in Inverness, someone will want them.

Slightly perplexed by the OPRV shedding its filter, I nipped it back up in the vice , then attempted to push it back out, ended up bursting the strainer and it wasnt that easy to push out, how did it get like that in the motor? Weird. I have some fine mesh kicking about to repair it. Plated the dome case and body today. After plating I thought I would check the OPRV fit in the case, sloppy would be a generous description, its slack when screwed almost fully home, there is perceptible shogle, such is the poor fit. I plan to place thread sealer inboard of the relief passage port with a cocktail stick on re assembly.
This would explain the flickering oil pressure light once the motor has been caned/ warmed up at speed.

I must thank either Rich B or Mr Mike, ( I think , hope Ive got the right folks, apologies if I have got the names wrong, who ever it was I am grateful) for drawing attention to this as a weak point in the oil system. I wouldnt have given it much attention otherwise.

Head and crank going away to Wales for a holiday tomorrow, new guides, bigger inlet valves, seats recut, crank repair DS and balance. Still have to finish attacking the piston valve cut outs with the dremel, half way there. Off to the smiddy to see how the frame repairs are going tomorrow.

Clearanced the gear box end plate, 5 minutes with the dremel , easy. The other end is a bit trickier , but getting there. Checked the cam plate swing AOK. Onto the main shaft soon.

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 03/09/16 8:23 pm

Nice idea Nick, I like the old AMC single system that ran the OPRV dump into the cylinder barrels to lube the bores at the bottom of the stroke ( think HD do something similar), not really practical on the A65 .
Any previous experience with crank scrapers?
Posted By: kommando

Re: alloy barrels for 750 OIF 1971 - 03/10/16 3:39 pm

Well the new fork internals are virtually finished, the work still to do will not effect what is available to view now.

[Linked Image]

And its covered in more detail in this thread so Gavin can keep his thread with no distractions.
Posted By: Andy Higham

Re: alloy barrels for 750 OIF 1971 - 03/10/16 4:18 pm

Gavin, I am intrigued by your DIY zinc plating, could you give us all some more details please?
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 03/10/16 6:21 pm

Kommando, beautiful work, cant wait to try this out.

This is the babbit ingot I mentioned, posting as a penance.
[Linked Image]

Denner. A Killie pie and real tea.
[Linked Image]

Cleaning and de- shrouding piston valve cut outs, need to do this before having the balance done.[Linked Image]
[Linked Image]

Crank in its traveling coffin.
[Linked Image]

Andy, I looked into getting a Zinc plating kit, then thought I dont need a 60 bucket and voltage controller.

Do not read on if you are scared of "Chemicals" and did Art instead of Science at school.

Acetic Acid , Hydrochloric acid and Electricity are involved, this is tech fun, dangerous, maybe life threatening if you are stupid enough. For people that can walk and chew gum only.
If you ever use the phrase " my mechanic" stop reading now, and go back to generating wealth to pay for other people to do your dirty work.
If you dont believe in climate change and / or vaccination, stop reading now, you can not deal with Science like this.

Watched a few vids on you tube. Did a little chemistry re call. At work we used a lot of electrolyte with Sodium Carbonate ( washing soda ) as a liquid resistor so I have some previous with electric soup as a motor speed controller. Want more current add more soda , fairly simple.
However , in Zinc plating what you want is a soup of Zinc ions in a suitably conductive mix. We are talking milli amps of current , so not wildly conductive. More juice just spits H2O up , you get a lot of gassing but not much plating. Zinc wants to say hello to less reactive ferrous stuff , it just needs mild encouragement , not kicked up the arse.

If you look up commercial Zn plating info the electrolyte soups are based on max yield minimum time max efficiency. Some of the mixes are pretty forbidding, I ruled them out.
In the spirit of " You can only piss with the cock yeve got " I decided to use whatever was handy.

Washing Soda ( Sodium Carbonate) , kitchen under the sink cupboard.
Tap water, where I live we have very soft water, daan Saff you have hard water , better use distilled stuff. I used it straight from the tap.

Vinegar , kitchen shelf.
[Linked Image]
Zinc, free at the boatyard, anodes get replaced and tossed as a matter of course.
Bucket, 15 mm copper pipe as top bus bar, Solid copper strands for linking anodes together and dangling victims in the soup.

Battery charger, with 6 volt setting and high low switch. ( more than 3 volts is a waste.)

I approached this in a spirit of experimentation, alchemy and the blind optimism of the semi ignorant, it works but may work better.

Half fill a clean plastic bucket with water , add about a pint of vinegar, malt or distilled, chuck in a couple of heaped table spoons of washing soda. Stir and season to taste ( kidding) , you can add sugar , maybe an ounce or two, molasses, treacle , whatever.( seriously ) it acts as a brightener, more silvery , less leadlike. Warm this to about 30 C if you can, not critical, but warmer is faster up to a point. Add zinc anodes, no wiring needed,
let this sit for a day or so zinc dissolves into the mix. ( This is why some recipes have Zinc Sulphate, it helps pre load the soup and speeds things up.)

While this is doing its Zincy soup thing, prep your metal. The plating is nano metres thick ( its not hot dip galvanising!) so the raw surface finish is what you will see when plated, file , vice marks an all.
Polish as required.
I remove rust with electrolysis in a brown soup ( Sodium Carbonate solution) bucket.
[Linked Image] A magnetic tool bar holds whatever is to be de rusted, this gets at least 24 hours at 12 volts to clean of old rust, battery charger used for this too, sacrificial anode is a lump of iron stove grating. Cathode is the magnetic tool bar with the victims stuck to it. Heavy corrosion, may need 2 -3 days. Rinse and brush daily. If you have a shot blaster this step can be omitted.

Buy a box of disposable gloves, wear them at all times when handling the victims.

A trip to the wire wheel to clean threads etc. Then pickle in 10% Hydro Chloric acid ( Brick Cleaner , Home base or some other DIY store), nb, nowhere on the container does it mention HCl , you need to look up the CoSHH info for that, amazing.
Do this indoors naked while drunk, or if you are the serious type go outside, wear gauntlets , old clothes and goggles. I compromise with gloves and some clothes and go outside, sometimes if its not raining..
Its stinky. and super corrosive, the fumes will rust any steel nearby , be careful.. I keep about a pint in a glass jar with a plastic lid and use a telescopic magnet to retrieve items after 10 minutes or so in the jar.
[Linked Image]Rinse thoroughly immediately , then if not ready to plate store in Meths or thinners to prevent rusting. This helps degrease as well.

Now get a bit of 15mm copper pipe, about 6 inch longer than the bucket diameter.
Flatten an inch or two in the vice and bend at 90 degrees, to hang down, lay across top of bucket( clean with steel wool first).
Connect Batt charger negative to the copper ( croc clip). The Zn anodes should have a 3mm hole drilled, save the swarf, chuck it in the bucket. Hang the anodes in the soup so the copper can pass through the holes but dont get the Cu in the soup., bend the cu so it hooks over the rim, connect all anodes together and clip to batt charger positive.
Set charger to 6 volts , low charge.
[Linked Image]Have some headlights handy with working bulbs, you may need them as resistance to lower current , depending on plating victim area and soup conductivity.

Cut a few lengths of Cu sinle core wire to hang from the copper so they are able to dip an inch or more into the soup. ( Croc clips are handy to clip to the top bar, if you have them. )
Take a few test pieces, say a half dozen small nuts/ bolts/ washers. Rinse in clean water.
Hang the victims in the soup with the Cu wires hooked over the pipe, a couple of tight twists round he individual parts will do, use nuts and bolts to nip the Cu where possible. make sure they dont touch the Zn anodes.

Switch on the charger and observe, you should see a fizzing of small bubbles round the victims.

Check the voltage across the Anode/ Cathode with a multimeter on DC volts scale, I get about 4 volts , possibly too much, bit its working well.

The first time I did it, I had it on 12V , hi charge, it didnt just fizz, it frothed, and some of the victims got burn marks. This was not right. Also I hadnt waited for the Zn to soak in. After an hour of frothing nothing happened no plating.
Now I know better.
other mistakes Ive learned from.
The ZN anodes get a white salty deposit after a while , Do not wash this off in the sink, brush it off into the soup with a brass brush, this is the goodness.

Plating is line of sight, keep re-orientating the victims, the more anodes the better,
[Linked Image] for all round soupy goodness. First attempt I had stuff plated one side , not the other.

If one victim isnt fizzing and others are, it needs a better connection.
Typical before item
[Linked Image]

Head nut after
[Linked Image]

Too many victims will stall the process,dont try to plate more than 2 or 3 parts at a time. This all depends on surface area, one big part will take longer than a few small parts.

Every 10 minutes or so , remove a part, and lightly brush with steel wool and rinse with water, then re- dip. Do this in rotation.[Linked Image]

My mix seems to need a top up with some vinegar every now and again, I think thats the free H+ ions being used up ( open to criticism /education here). If nothing is happening and it all worked OK before add a little more vinegar.

My bucket has precipitate in the bottom. ( My free ZN anodes were not what you would call chemically clean , manky would have been a better description). After the first 24 hours I binned that stuff, but it has since re appeared, when stirred up this seems to encourage the process.

Use the Cu dangler as a guide to how plated your victims are , if the CU looks Silver, its pretty much done.This pic shows the blackish marks which are removed by rubbing with steel wool, "carding" Rinse , dry , polish , done.[Linked Image]
Ive had no overplating issues or excessive or granularity, thats how inefficient I have made it. Your results will probably vary.
Its time consuming, but educational, cheap and amusing. I am most pleased with the results.Its not difficult. If you can boil an egg, and make tea, and know your arse from your elbow you can do it, although some chemistry training ( well done Mr Gibb,all those years ago, I eventually got a B for chemistry.) it will help.

You can selectively plate certain zones, like the end of the rear brake cam spindle by just dangling the end in the soup, no need to plate the whole bit, same for wheel spindle/ axle ends.
Any Qs, ask away.



Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 03/13/16 12:00 pm

Thanks for the gen Nick, very good to know. I dont have any old OPRVs in stock, unfortunately.
Re reading my plating post, I sound a bit judgy towards Climate change skeptics, , higher earners and artists. Probably because I am. I thought about deleting the "dont read any further" bit, then though, "whos paying for this?" , me. so no editing needed. If I have offended anyone, sorry, but hey ho. On with the job.

Looking in the manual, " Check the oil pump joint surface is flat", never done this before, assuming all was OK," what ye dinna ken cannae hurt ye" etc..
Not OK, as found all stud mount holes were Pulled UP, blacked up the face with marker pen,
[Linked Image] trial shimmy with pump,
[Linked Image]scrape till the high spots are gone.[Linked Image][Linked Image]
From the looks of the joint face , the bare cases must have been rolling around in the back of a van in a bag of spanners being briskly driven up a twisty B road. Through the magnifying glass it was a ploughed field. Skilled technicians worked feverishly though the night until no more high spots showed up.

Got the pistons spruced up for their trip to Wales.
Knife edged skirts
[Linked Image]
Polished and de shrouded cutouts
[Linked Image]

Oil pump end plate,
[Linked Image]pretty clean, very light witness marks, this was dressed flat around 2000. Happy with that.
Feed pair
[Linked Image]

Return pair
[Linked Image]
The body
[Linked Image]

Looked in at the smiddy to see what progress had been made with the frame. It was still sitting where I left it. This is very much the West Highland Way, where there is no word in the gaelic that conveys the urgency of "manana". I will need to apply subtle pressure by inventing a dead line and threatening members of the MacKenzie family with dire consequences. To be fair they are busy, 9 welders all looking active ,I will go down, offer to lend a hand with prep work ,get in the way a bit, that should up the ante.
Posted By: Andy Higham

Re: alloy barrels for 750 OIF 1971 - 03/13/16 2:41 pm

Gavin, current thinking is not to knife edge piston skirts but to radius and smooth all the edges
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 03/13/16 4:04 pm

"Gavin, current thinking is not to knife edge piston skirts but to radius and smooth all the edges"

Bugger!, ah well it didnt do the last set any harm. Will radius whats left around the skirts, only the thrust faces have had any treatment so far.
Have the feed NRV ball seat lapped now. Pump re -assembly time. Amost finished the plating jobs. Painting underway, fork build up imminent.
Posted By: Andy Higham

Re: alloy barrels for 750 OIF 1971 - 03/13/16 4:24 pm

Its funny how ideas change. Years ago tuners used to mirror polish inlet ports, now it has been discovered that slightly rough finish actually flows better. I believe it is similar to the effect of dimples on a golf ball making it fly further
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 03/14/16 7:14 pm

"Years ago tuners used to mirror polish inlet ports, now it has been discovered that slightly rough finish actually flows better. I believe it is similar to the effect of dimples on a golf ball making it fly further"
I am ahead of the curve there, my inlet pots have a similar texture to a badgers arse!.

Crank went away today.Got stuck in a traffic Jam in Oban for an hour, I didnt think that was possible. Unseasonable sunshine for more than two days. After the hottest February ever. Will crack on with painting and gearbox fettling while the cranks away.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 03/18/16 5:35 am

Frame update, visited the smiddy fully prepared for nothing to have happened, but Lo!. The side stand scabs have gone, and work is underway on the footrests. While Chris Mackenzie is on the job he will fill the fork stop notches where they had bitten in and restore a little fork leg/ tank clearance when on full lock. Last welding jobs will be the shortening of the centre stand and the new side stand mount..
Alloy tank brace fabbed up, case joint cleaning almost done, more painted bits. Will plate all top end stud ends to lose the last bits of obvious rust.

The " bargain " air box, panels and rubbers arrived from over the pond. Handy spares, the centre box part is true and un-cracked, this may be used in the build up.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 03/29/16 7:13 am

Current state of play. Awaiting word from SRM, bits are in a holding pattern, e mail to follow after inspection.

messing around with cases, prep work for cluster clearance completed. layshaft clearances completed.Next step will be selector checks. Noted while playing with case halves that there is a bit of scope for misalignment of case halves, barrels must be temporarily fitted BEFORE tightening case fasteners to ensure correct alignment.

Pondering on using Loctite 565 thread sealer on OPRV to seal correctly any thoughts/ criticisms welcomed.
Posted By: Bougor

Re: alloy barrels for 750 OIF 1971 - 03/29/16 7:44 am

I had the bottom engine mount bored and fitted with a sleave, one side slightly extending into the other case half to resolve the problem of misalignment.
The cases slap back together in the same spot every time.

Posted By: kommando

Re: alloy barrels for 750 OIF 1971 - 03/29/16 7:55 am

On the Unit Singles there are 2 joining stud holes bored oversize for 3/8" diameter 1/4" depth and then threaded for 5/16" studs and they are hollow dowelled so that the cases are aligned with no play.
Posted By: Allan Gill

Re: alloy barrels for 750 OIF 1971 - 03/29/16 8:06 am

Had any desires to change the cam Gavin? The SRM race cam gives the bike a lot of torque.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 03/29/16 9:21 am

I thought about it, the heavy valve springs put me off, thats a lot of extra wear and tear on the valve gear, fine for racing , Ive seen what happens to cam lobes with WnS valve springs, I dont plan on regular tear downs . Accelerated wear is not part of my long term plan. If I was racing then yes, otherwise the Spitfire profile will do for me.
Posted By: kevin roberts

Re: alloy barrels for 750 OIF 1971 - 03/29/16 11:04 am

perhaps one of the beehive spring manufacturers makes one for the BSA?

the kibblewhite beehives for a triumph are set at 90 pounds closed, with more lift available than the motor can take. R/D makes beehives for the BSA C15, and may have a crossover?
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 03/29/16 11:18 am

its not so much the weight as the added spring pressure that causes the wear, more forces on the cam , followers and guides, I seldom rev past 6K. Over 5k my mantra is Forces ,Pressures and Speeds, all increasing on a nasty steep curve.
Posted By: kevin roberts

Re: alloy barrels for 750 OIF 1971 - 03/29/16 12:28 pm

yes. the kibblewhite beehives for a triumph are lighter than the r/d beehives, which run (according to dan at franz and grubb) around 120 pounds seated. versus what, 65 or 75 stock? so there is more pressure with either beehive.

on the other hand, i've been running stupid-high on my old T120 for years-- PM springs that measured out at 220-plus over the nose, if i recall correctly-- can't remember seat pressure. they've been trouble-free, but mostly because of dumb luck on my part, i think. i bought them from MAP way back, to use on a megacycle 1000 cam, and didn't know what i was doing.

i think the thing about springs is you have to decide just exactly what you're doing with them first, and then don't use any more than you need. so you've been smarter than me.
Posted By: Allan Gill

Re: alloy barrels for 750 OIF 1971 - 03/29/16 1:27 pm

I've used the SRM RACE springs and the Ed V road springs. Both are better than the Mca crap and I am yet to find accelerated wear. Both springs will also take high revs.
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 03/29/16 2:40 pm

Got the frame back, , footrest mounts look tidy and the weld repair to the airbox is invisible, nice work by Chris Mackenzie. Still to fit a side stand lug , will need a rolling chassis to get the angle right. This poses a bit of a conundrum, paint all the frame except the mounting area and touch in later, or assemble , weld, disassemble , paint. probably go for the first option.

Offered the bare cases up to the frame to check mount clearances, a 20 thou washer is needed to take up clearance at the lower mount to prevent "springing" the frame , others here have found that this reduces vibration. I have tried to fit one of these before with everything bolted up bar the lower mount, it wasnt happening. Looks like the front mount needs a similar shim. onwards and upwards.
Posted By: Bodger

Re: alloy barrels for 750 OIF 1971 - 04/06/16 6:20 pm

Boy am I confused!!

I love this thread Gavin, I was treating meself to a page or too if I been good, and in the last two weeks it went from 17 pages to 9!!!

What the heck happened?

I wuz on page 15 dated 2/17/2016...'you betcha I feel cheated!' it, and thanks!
Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 04/08/16 9:19 pm

I dont know, nothing has gone at my end. Did you change the page settings?
Just back from 4 days at sea. So not anything I did.
Posted By: TR6Ray

Re: alloy barrels for 750 OIF 1971 - 04/08/16 11:54 pm


It is on your end. Click the menu "My Stuff" at the top of this page. Then click "Edit Preferences". Scroll down to where you see "Total topics to to show per page (default is 25):". Set the number back to 25. Right below that is another setting, "Total posts to show on one page when viewing a post in flat mode (default is 25):". Set that to 25 also.

I am betting your numbers are higher, like 50 maybe. That won't change the content of Gavin's thread, but if your numbers are set to 50 posts per page, you will have your 9 pages. If you only have 25 posts per page, you will have 17 pages.

Posted By: gavin eisler

Re: alloy barrels for 750 OIF 1971 - 04/09/16 6:36 am

Some pictures of the Rothesay Victorian toilets, my justification for posting these is that many BSA owners have used these toilets ( amongst others).
For clarification these incredible toilets are in Rothesay on the Islw of Byte in the Firth of Clyde on the West coast of Scotland. I recommend the Golfers bar in town for great beer and the finest barman i have ever seen.

Sanda Isle just before we entered a maelstrom.
[Linked Image]

The Bute coat of arms
[Linked Image]

[Linked Image]

Skipper and vessel, available for punishing sea tours andd sea monster spotting.
[Linked Image]
[Linked Image]
[Linked Image]

The "Deluge", the titanic came with leather retaining straps I imagine.
[Linked Image]

Cabin boy relaxing
[Linked Image][Linked Image]
Goldstar stylee
[Linked Image]
[Linked Image][Linked Image][Linked Image]
The keel inspector
[Linked Image][Linked Image]
Posted By: kommando

Re: alloy barrels for 750 OIF 1971 - 04/09/16 7:12 am

I always have thought that the inspiration for the band name 'Adam and the Ants' came from the Adamant on old loo's ;), they also sounded like they recorded in a toilet. Much better to have polished copper pipe over chromed pipe in bathrooms. Pity you did not get down to Troon and try out the Wee Hurrie, best chippie in the Firth of Clyde.
Posted By: triton thrasher

Re: alloy barrels for 750 OIF 1971 - 04/09/16 9:08 am

Originally Posted by kommando
I always have thought that the inspiration for the band name 'Adam and the Ants' came from the Adamant on old loo's ;), they also sounded like they recorded in a toilet. Much better to have polished copper pipe over chromed pipe in bathrooms. Pity you did not get down to Troon and try out the Wee Hurrie, best chippie in the Firth of Clyde.

Don't you remember Adam Adamant?

[Linked Image]
Posted By: old mule

Re: alloy barrels for 750 OIF 1971 - 04/09/16 5:35 pm

In the British Museum there is a strange old exhibit on toilet includes a cut-away toilet with clear pipes, designed to show the workings to those who cannot figure it out. It is a working model. It includes a realistic looking turd made of some turd-like substance. When the viewer presses the valve lever, it flushes and the progress of the turd may be followed as it progresses down the clear plastic u-trap and pipes.
Ahead of me in line was a Chinese family, kids all bored Londoners but the granny just in from the old country. At the sight of this contraption she fell into hysterics, laughing and pointing until kids and grandkids were dying of embarassment.
The episode brightened my day.
Back to motorbikes now, I suppose.
Posted By: Andy Higham

Re: alloy barrels for 750 OIF 1971 - 04/09/16 6:16 pm

In our Lancashire (and probably other areas as well) we had a device called a "tippler toilet". A rather ingenious piece of kit, it was a toilet in an outhouse, quite deep the "U" bend was about 1.2M below ground. There was a side branch connected to a pivoting dish shaped "tippler" which was filled with water from the kitchen sink drain. When the "tippler" was full it over balanced and tipped all the water down the toilet, flushing it.
A perfect example of recycling
Posted By: kevin roberts

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 04/09/16 7:10 pm

when i was last in the british museum the toilet paper was all marked-- individually, by squares:

property of her majesty ER II

still that way?
Posted By: Bodger

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 04/09/16 8:02 pm

aha!....indeed preferences had been reset by graemlins to '50' the little buggers!..thanks.

hmmm...toilets huh?..reminds me of the new Hong Kong made yacht my friend was vetting, the new engine was stalling and the injectors were clogged, filters clogged..several other boat workers had given up, but my friend got to looking at the clog debris with a magnifying glass and could see the stars printed on the toilet paper, holding tank was plumbed to the diesel tank.

Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 04/14/16 10:33 am

Eventually, got my land legs back, SRM called today, head and crank work completed, sundries ( seals gaskets and tab washers added to order, expecting bits within a week or so.

Paint hardens as the peach blossoms.

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Chaos/ with lightly condensed areas of order.
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New footrest mount.
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Invisible air box repair, crack no more
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Paint in primer as sanding progresses, worst stuff is cleaned up, downtubes and seat rails, the rest is getting a light rub and primer.

Aldis have 1200 lumen Cree cycling lamps in, comes with assorted mounts, remote 7.4 volt battery pack and charger, 2 hr life. 40. This lamp is going on trial, Its approx 5 times brighter than the 45W QH bulb currently fitted. Push bike stuff, but pretty solid. Any one tried it.
Posted By: kurt fischer

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 04/14/16 6:58 pm

Looking good, Gavin. Soon all those pieces will jump together into one big piece.
Posted By: Allan Gill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 04/15/16 3:18 pm

Nice work! What colour are you doing the tank?

Looking at your frame it's nice to see the factory learnt how to weld neatly by the 70's my 68 (67 built) Lightning has awful welding by comparison.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 04/15/16 9:36 pm

The steel tank stays red , the alloy tank will get polished with a BSA Star decal.It had one before.
The alloy tank has a new front brace and re- located taps, still to be annealed though.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 04/24/16 9:59 am

Exciting parcels from SRM,

head , cleaned

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Fins repaired
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Big valves.
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Assorted goodies
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New guides.

Inlet ports need more work, I opted not to have new seats fitted, the valves look a bit pocketed now.

Crank with some fresh balancing holes, re ground big ends and sleeved drive side .

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Frame in suspension on roof pulleys, nearly finished
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Painting materials, 2 x 250 ml cans of Cellulose primer and gloss black, enough for 2 coats of each, thinners and a quality brush. The 1/2 inch brush I was using shed its hair on the last coat, bugger. Cans found at the back of the shed, cost 2.50 each! pricey.
[Linked Image]

Looking at idler pinion end float, its massive ( well pointed out John Hill) looking for suitable shims. Motor assembly coming soon while the paint dries.
Posted By: Ger B

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 04/24/16 12:58 pm

Wow. Those inlet valves seem huge. :bigt
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 04/28/16 10:10 am

Idler pinion end float corrected with two shims cut from the end of a tomato can, then JH reminded me that he had given me some suitable shims already , Doh!

Been getting at the gearbox.

General arrangement , showing selector forks which are interlocking, numbered 19, 18 Layshaft ,( 17 mainshaft)[Linked Image]

Lay shaft with 1st gear removed and roller exposed, thrust washer RHS.
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Lay shift 1st gear female dogs.
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Checking layshaft fit, discovered the shaft was bottoming in the DS bearing, heated the case and knocked the bearing out about 20 thou, after doing that the lay shift fitted with about 2 thou end float.Pleased with that.
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Set up for check, main bearing hole used for access to push shaft.
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Found that i hadnt created enough clearance on the outer plate for 1st gear

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, and at the inner casing around the layshaft bearing DS, another hour oer so with the dremel and all was good.

Cluster and cam plate shing selector tracks, a good position for assembly.
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1st gear position
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4th gear
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5th gear
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Cam plate and different gear positions

Test fit of cluster , spinning shaft and moving cam plate to help ease in
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Still messing around, the shift to first is challenging, going to shim the cam plate to prevent it tilting and see if that helps.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 04/28/16 10:56 pm

Should I de pocket the areas around the valve heads?
Playing with the layshaft shim, done I hope, but too much midnight oil, have a lay shaft end float about 0. 0038", had to stone down the thrust washer it took 3x 48 cycles on a 300 grit stone., at 2 thou end float 2nd gear was ticht , the rest were fine.
As a trial I used a 10 thou smaller thrust washer, this freed 2nd up, so I know I need A bit more clearance. Have a more secure clock set up now. Will post pics tomorrow. Have got all 5 gears , 1st to neutral is tricky but the rest are sweet. John says , you get that with them.. Found more clearance issues on the main shaft TS bearing housing , it was saying hello to the first gear, squeeling was a good clue!, as was the rim of the end plate by about the same, sorted by scraping, took about 5 thou off to get a 2 thou feeler in all round.
Posted By: JER.Hill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 04/29/16 1:21 am

Hi Nick

Thanks for the tip on the GL5 synthetic oil we'll give that a try. What Gavin said about selecting 1st to neutral from a stop was tricky when I was testing the cluster, 2nd to neutral is slick, rolling to a stop 1st to neutral is also fine. I did think about easing the ramp a little, but decided to leave it as you never catch neutral on the way to second even under hard acceleration.

The back cutting of the dogs was one of the first things on the wish list when I started looking at the 5 speed project. As this helps eliminate many of the issues associated with the original A65 gear cluster.



Posted By: Allan Gill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 04/29/16 3:54 am

I'm a little confused John I spoke with mark at PES (he's cutting some valve seats for one of my A65 heads) I mentioned I had a CR box which worked very well and that the gears were under cut (presume back cut being the same thing) he told me that these boxes 5 speed boxes were not back cut for the same reasons that you recommend they are.

However. It looks a beautifully made box and I wish you all the best with its success, Mark is an excellent engineer and whilst I was there he was showing me some of the things he was doing with the unit singles which I suggested could be done with the twins too. Let me know if you wish to discuss further.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 04/29/16 9:46 am

More progress, took another thou off the layshaft shim cleartance over 4 thou now, no tightness in 2nd , and everything else shifting corectly. Cam plate like one shim above and one below.
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No friction or noises and all selecting, sweet.
Pic shows areas relieved on TS bearing plate.

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Witness marks on face of LS 1st
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Tools used to help with clearancing
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Clutch centre on
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Clutch centre off, time 4 seconds, what a joy !

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and again for emphasis
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Fitted bearing carrier plate to rear of clutch with both c/cases and barrels for alignment, all shafts, gears spinning free.
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Mount doom out the workshop window
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Barrels in foreground
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State of play. barrels need cleaned up, awa tae Dundee for a meal with No.1 daughter.
More next week.
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Posted By: kommando

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 04/29/16 10:47 am

Ahh you got snow overnight too, we got it too and its still only got to 5 degrees C in the workshop.

Good progress with the gearbox, that camplate looks good and meaty with the extra thickness.
Posted By: JER.Hill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 04/29/16 2:34 pm


First in answer to Allan's post. Are you sure your not getting mixed up! While the original system was parallel gears and not designed for back cut (undercut) gears. My 5 speed cluster does have as stated back cut (under cut) gears as it was designed for this.

Second, in comment to Gavin with regards to his timing side bearing plate cover. Your clearance issue with the mainshaft timing side Brg casing clash. This is a clearance issue so far not I've not en-counntered, although to be honest yours is the first OIF model that I'm aware of the 5 speed cluster being installed in.

As always all comments welcomed

Posted By: Allan Gill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 04/29/16 4:05 pm

That could be what he meant John. As he never mentioned the 5 speed was back cut.
Posted By: JER.Hill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 04/30/16 1:34 am

Hi Nick

Glad you like the look of the cluster. The original aim was to have a 5 speed cluster that you could swap out for your old 4 speed. The cases we had in the shop were fine, although it was recognised that under that selector plate mounting need a small amount removed for the 1st gear. It fitted straight into my test bike with just that one change, so we thought we'd got it right.
I got a scrap casting to cut-up to make a dummy casing with a large window so everything in the bolted together state could be seen working, this had a few light clashes, nothing that a couple of minutes didn't sort out. The clash on Gavin's Brg plate around the mainshaft is the most significant amount of metal that's need to be removed.
I don't really want to get into making a new Brg plate, as that is more machine time and ultimately more cost. I need to have a think on this.

Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 04/30/16 4:11 pm

It wasnt a lot of metal to remove , 5 or ten thou, I missed it the first few assemblies, trials with pushing the gear towards the plate showed up the clash, easy fix maybe a 30 minute job.
Posted By: JER.Hill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 05/01/16 12:22 am

Hi Gavin

Thanks for that, in your photo the marking material made it look much worse. None the less its a clash I've not come across before.


Posted By: Mark Parker

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 05/02/16 6:47 am

I had to shim the layshaft back because shifting into second was pushing against 5th and binding it up. So moving the layshaft (and 5th with it) toward the drive side gave 2nd clearance to select without pushing on 5th. When you shim under first to move the shaft, it moves 1st away from where you are removing metal on the bearing plate. It actually moves it so you get best engagement on all the gears. And it lines up better with the mainshaft gear. It can be checked with the cluster out of the cases and just the layshaft and selectors for it assembled with cam plate. I think it is better to get that right first then shim on the drive side to get correct end float.

I also had the layshaft bottom out in the needle bearing on the drive side and took a little off the end of the shaft.

It may be that later models have the layshaft locate slightly different to the cases John used to set it up. My cases are 1970.
Posted By: Mark Parker

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 05/02/16 7:11 am

Nick, this 5speed would have transformed your outfit. 1st is lower than BSA C/R 1st same with 2nd so getting going is better and each gear is just where you want it. Going back a gear is not daunting, its only down a bit, and the next one if you need lower is there. On top of that it's quiet. I could tell what gear I was in before with the 4speed because of the noise, it wasn't drastic but was there.

The ratios are close and very performance orientated, but really whatever a bike was used for it's probably best like this, better ratios than I had in my T150V.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 05/02/16 1:52 pm

brilliant Mark , will give that a try, last trial with barrels and all cases , all shifting well but still stiff in 2nd.

Noted my crank cases didnt have the 5/16" dowel fitted in the location at the top front of the cases joint.
Tried one in, , doesnt line up, creates a barrel flange error and doesnt allow the clutch brg. plate to enter the shaft. The dowel stays out! Barrels as reference working OK , so not changing this.

Also noted new blue SRM base gaskets are a bit thinner than the old black stlylee, 0.016", blue, 0.025" old black stlye.More CR ,yay"
Posted By: Allan Gill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 05/02/16 3:05 pm

And they leak. Least mine did. The gasket I got from Ed V was fantastic.

For oil pump gasket I can highly recommend those from David Drew, as sold
On eBay. They line up perfectly
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 05/02/16 6:42 pm

Just in from making changes recommended by Mark, more better, 10 thou shim on TS of layshaft, and 67 thou shim on DS. No more stiffness in 2nd. All gears selecting positively.
Also found the missing Ally spacer that fits between the drive gear needle rollers. its loss caused great concern and bench searching, re appeared 24 hrs later with a knowing Klink as it fell to the floor. I had one almighty bad trial when the box wouldnt shift much and once in 1st not at all, turned out the drive side layshaft new / old shim from previous cluster, was belled and locked everything up if fitted the wrong way round. I have also eased the cam track passage for 1st gear slightly with a dremel, John has supplied these with an eye to racing, where 1st to neutral is not an issue, but I kinda like it to be an option.. Now getting it fairly easy compared to before.
Posted By: GrandPaul

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 05/03/16 9:20 am

This thread would keep Franz Mesmer very interested...
Posted By: GrandPaul

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 05/10/16 10:03 am

NINETY-FOUR THOUSAND plus views on this thread!

I think it's a record.
Posted By: Allan Gill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 05/10/16 1:59 pm

Originally Posted by GrandPaul
NINETY-FOUR THOUSAND plus views on this thread!

I think it's a record.

Not quite Paul. 148,*** on the Lightning resto.

More importantly any more progress Gavin? I'd love to be in a position to finish mine at the moment.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 05/10/16 6:05 pm

Just back from helping a friend fix his boat, nothing done for four days.
Ready to finish clean and re assemble motor after tapping 4 more 6 mm holes in clutch support plate , I have added 6 more 6 mm c/sunk allen screws to help with the bearing loads, these were spaced according to where there was enough meat on the primary inner casting. Tank in at local painter and new BSA decals came in the post so that should be done.soon.
Kommando has sent some shim adjustment info for the fork mods and recommends I start with 10W.
Went to fit the swing arm last week and found that I had "missed a bit " , should be ready to re assemble/ rewire soon.

Posted By: Mark Parker

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 05/11/16 5:01 am

It doesn't hurt, but you probably don't need the extra screws in the support plate, I stick the thing on with 3bond supersealer silicon with a dab of loctite on the screws and have never had anything come loose during the years I've used a support plate.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 05/20/16 9:07 am

Family life interrupting work.Also Cagiva Raptor had gone in the sulk and needed vaseline ( Multi pin connectors) and fluids before passing the MOT.
Realized I was about to reuse the original big end bolts for the 2nd time, wimped out and have ordered new set plus a new set of c/case fasteners , that last pic of the ventilated cases did the trick. Opted as well for a new idler pinion spindle to match the new bushes on the shelf, the old one is not very parallel anymore.
Forks rebuild under way. Kommando had sent a few shim adjustment mods and now all is good for rebuild.Will push on with the chassis , paint is cured, and theres a gap before motor parts appear.

Kommando is " man down " at the moment, wishing him a speedy recovery.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 05/23/16 6:47 am

messing around with the brake pedal, it mounts further inboard now.

Using soap and propane and a lever , bent an increased crank into the lever.

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Travel limits. needs a 1/4" spacer between the frame and footrest to fix this, will use the switch mount plate as a spacer.
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Oil filter , mounts on a U bracket,
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Test assembly of new forks sitting on the Ark of the covenant.
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MZ fork gaiters, cleaned the ribs on the stanchions to lose battle scars, fitted Kommandos new dampers, had to cut 80 mm off the springs ( 50 for shortening plus 30 for the increased height of the damper stack), rate now 29lb/ft, compared to 24 lb/ ft originally.
assembly for trial only, still to fit seals and fill with oil.50 mm spacer added under damper head to reduce travel from 6.5" to 4.5", this will lower the front end by a tad, the sag with the new fork springs will be a lot less than the original soft spring rate.
Older forks without high speed comp damping had softer springs because the damping was so crude. Now with high speed/ low speed damping the spring rate can be raised a tad, safely, with the improved damping giving greater bump control. Thats my theory any way. I have other springs to try if these end up too stiff. Edit, they ended up too stiff, at 28 lb/ inch, up 3 lbs from stock 25, going with softer MZ front fork springs.
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Waiting for a new idler pinion and big end bolts before the bottom end can be completed.

Pattern parts problems, new swing arm sleeves/bobbins, are undersized on the ID, wont fit over SA spindle, will bore to suit when I get into the underground lair. Wassel junk.
Its just struck me that if these bobbins were bored eccentrically and keyed to the spindle then the swinging arm would be " adjustable "for fore and aft, up and down, probably pointless complication though.
Posted By: kevin roberts

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 05/23/16 10:49 am

what do you use soap for when bending metal?
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 05/23/16 1:15 pm

Rub alloy with soap, heat till soap turns black, bend metal, soap blackens at the annealing temp.
Posted By: Allan Gill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 05/24/16 4:55 am

:bigt saves you weakening the al'
Posted By: kevin roberts

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 05/24/16 7:39 am

i didnt know that.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 05/24/16 11:51 am

Annealing point is very close to melting point with Al alloys, the soap saves embarrassing meltdown. Handy for clutch and brake lever repairs . If using oxy acetylene , a sooty flame is played over the alloy to blacken , then a clean flame is used , when the black disappears the alloy is annealed.

Big end bolts and stuff arrived today, but the chances of a quiet day for a rebuild are not good just yet, too much family stuff going on.
Posted By: kevin roberts

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 05/24/16 1:59 pm

okay then

i have to ask, because this is really interesting.

what kind of soap? glycerine? tallow? olive oil? petroleum? does it matter?

what kind do you use that works?
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 05/24/16 6:22 pm

i use Cussons Imperial leather hand soap because I like the smell, regular soap nothing fancy. Not liquid, nor oil, nor petroleum.

Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 05/29/16 6:55 pm

A slow week, parts problems still unresolved, need a 5/8" drill to open up the swing arm bobbins ID, new idler bushes , only one was correct , the other was wrong OD and ID, nippy e mail sent to SRm.
Progress , but slow.

Test mock up, brake pedal issues resolved with a bit more heating and bending. Clutch back plate work complete, yokes on, wiring , mudguard etc soon.
[Linked Image]
Posted By: old mule

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 05/30/16 6:10 pm

Nice work. I didn't like OIF frames until I got one. And then I read that they're only 6 pounds heavier than a down-tube type Seely frame!
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 06/01/16 7:20 pm

Thanks, I like its simplicity, the all up weight can be trimmed a lot from the stock 385 lbs, making a pretty nimble cycle.

SRM sorted the idler pinion out as fast as they could, got the bit next possible post, it was a Bank Holiday weekend so ,the post was out for 4 days. Its scorchio here now, 5 days solid sun, the Scots are turning pink.
Cattle are in the Lochs and all the bluebells are giving it heaps. England is getting floods, woo hoo. makes a change. Any way will crack on with reassembly of the motor soon. New big end bolts at the ready. Paint chipping on the frame at exhaust header mounts, touch up time.
Posted By: kommando

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 06/02/16 3:45 am

Cattle are in the Lochs

SPA down here would be having a fit, they surveyed all the local farmers with a burn (stream) running through a field 2 years ago, complaining of the cow poo getting into the water and affecting their water purity tests. So one farmer offered to fence off the burn, SPA guy replied but no then the local wild life could not get to the water and drink, farmer then asked why is wild life poo ok but not cow poo. Cue rapid departure of SPA back to office in Ayr.

More hot weather on the way !!!!!
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 06/05/16 5:39 pm

Just back from a porpoise/ litter spotting trip on the Clyde, never been so warm at sea, burned , but not too badly, a Scottish roaster. Costa Del Fairlie. Boat work, Shaft coupling realigned and shaft gland settled in. The coupling was about 8 thou wide at the bottom, trued it up with the front adjustable mounts, nae shims , easy. Now much smoother , but the gearbox whine is grim. Hurth marine 2:1 gearboxes anyone? Fitted to Perkins 4 cylinder , 50 hp motor. I reckon the thrust bearing needs changing. Saw loads of porpoises and a dog crap in a bag floating around at Millport.
The porpoise stuff is getting techy, got 150 K Hz hydrophones to play with next time.
Any way, bike stuff will resume tomorrow. On the trail of the expanding reamer to final fit the new idler pinion bushes, a man in Benderloch has what I need.
Posted By: Allan Gill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 06/05/16 7:33 pm

I just have an 11/16 reamer for these. Bit of the pain to get going but it gives
You the book specs clearance.
Posted By: JER.Hill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 06/06/16 2:30 am

Hi Gavin

If you get stuck give me a call, can pop it in a jiffy bag.

Posted By: Ger B

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 06/06/16 4:02 am

gearbox whine is grim. Hurth marine 2:1 gearboxes anyone

Are you sure it's the gearbox?
Propeller blades can also sing terribly if the anti singing edge on the trailing side of the blade is not correct.
The edge must be 2 x 20 degrees.
Another possibility is cavitation damage.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 06/06/16 7:54 am

Thanks all. I may pop over for a run John, weather is good for it. Ta for the info Allan,
Ger, Great info, did not know about anti singing edges, fascinating. The prop was clean and pitting free when examined up on the dry ( will check angles next Winter). With the hatches off the whine was definitely from the gearbox at the rear of the block. I suspect a few thousand hours running with the shaft misaligned will have taken a toll on the gear shaft bearings. The cutlass bearing as found showed severe wear, new one fitted now.
It is a Hurth box, has opposing helical gears ( so should be quiet) and taper rollers all over it in the drawings, but does not have a good rep, particularly when fitted to a 50 hp power unit. Job for next winter.
Its a good friends boat , he sails professionally and it gets a lot of use ( Jeanneau , Sun Fizz 40),used for RYA training and Marine Mammal spotting/ monitoring. I am now upgraded from Cabin Boy to Chanty Wrastler .
Back to the idler pinion. I was surprised at how worn this was , the pinion shaft was 2 thou down in places, hoping for crisper timing and less ambient noise with this refreshed.
Posted By: Ger B

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 06/06/16 8:13 am

Cutlass bearings with inadequate water lubrication can also be very noisy due to stick slip
when inadequate water supply prevents the formation of a hydrodynamic lubrication film.
Check the water flow and upgrade yourself to chief superintendent engineer. :bigt
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 06/07/16 4:54 am

Hi Ger, new cutlass brg has longitudinal flutes, all the googling points to a worn output shaft forward taper roller and thrust washer wear. These Hurth trannies are build down to size, not very " marine".
Back on with the BSA, must phone the painter and see if the tanks ready.
Family diversions are all over, newly found brother has returned to Seth Efrica. Head down now.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 06/10/16 8:14 am

Back on topic, took a run over to see John Hill, reamed the idler bushes, now a lovely fit. Also reamed the undersize ID of the swing arm bobbins/sleeves, they were tough " harder than a hooers heart " , another lovely Scots engineering description. Also took a few thou off the swing arm spindle to help ease the fitting.

Note bluing where I attempted to drill out the bobbin, drill wouldnt look at it.
[Linked Image]

Showing return hole for outer idler gear oil scroll, drilled after fitting, noted the original bushes did not have this, they had a twin scroll, LH and RH. Although the casing does have a corresponding hole which was used to pilot this drilling, without it oil can accumulate at the seal.
[Linked Image]

New shaft on idler pinion. With zero radial play. lovely.
The fit of the old one was "like throwing a sausage up a closie ( alleyway in Glaswegian)"
[Linked Image]

Old pinion shaft and bushes
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Oil pressure relief valve holes.
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Gearchange return spring and eccentric top hat for adjusting spring tension, left well alone.
[Linked Image]

Got home, tried the fit in the swing arm bushes, OD is oversize as well, spent a couple of hours with the bobbins mounted on rubber sleeve internally with a long 3/8th bolt passing through as a mandrel in the chuck spinning in a drill press and eased down the OD to 0.9975 , now a good bearing fit. Wassel parts, never again. The swing arm bushes are AOK, water damage on the old bobbins couldnt be ignored ( although it felt fine with no play, should have left well alone),.

John had a few tips. Cam gear and idler gear bush casing oil holes to be chamfered to improve feeds.
Swing arm getting mounted soon.
Also noted water damage on timing side needle roller, tried to find the brg number for this , INA or SFF KNIB something. Anyone know for sure?

Posted By: kommando

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 06/10/16 9:18 am


That will be INA or SKF,

The NKIB range is here at page 169 onwards, cannot find a KNIB range

Or play around with the dimensions on this page to get the full part number

Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 06/10/16 10:11 am

Ah, thanks John, my typos wont be helping.
This looks like the ticket
Posted By: JER.Hill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 06/10/16 10:26 am

Hi Gavin

Sorry didn't know you were needing the number, INA NKIB 5907 BNA C3 or FAG NKJB 5907 C3.

Posted By: Allan Gill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 06/10/16 1:33 pm

Gavin. I would be interested to see how far into the motor does the bearing stand proud. Both yours and my motors were devimead conversions and my bearing actually stood proud of the thrust washer retaining part of the casting
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 06/10/16 4:21 pm

Bearing ordered thanks to both JHs

Crank end with inner brg sleeve
[Linked Image]

Showing brg outer thrust collar, this overhangs the crank a nominal 2 mm or approx 85 thou"
[Linked Image]

Overall width of inner sleeve and collar 30 mm approx or 1.118 ish ". As stock NKIB 5907.Using electric guessing stick, parts loose so figs are not dead accurate, mm figs are "nominal"

Crank pinion abutts brg outer collar, not fully on ( and round the wrong way , sorry.terrible focus and manky gear.)
[Linked Image]

Like this, bugger , collar is upside down,but you get the idea, festina lente.
[Linked Image]

Got the swing arm on, lumps are getting bigger.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 06/15/16 4:19 am

While mr SKF is making the new brg I ave been mostly wiring.
After 8 drawings ( done last year ) I settled on a 4 relay system with 3 fuses.
All the relays coils are supplied through a 5 amp fuse which I call the "control fuse"
First relay on is the master relay.
Here it is under the coil bracket, fuses on top, reg rec mounted below battery carrier, Boyer in side panel.Tucked in on the left is the breather catch bottle , made from beach litter, an ex deodorant aerosol can, with a bit of re shaping.
[Linked Image]

The key switch operates the MR coil, this powers up ignition and supplies the other 3 relays.
Next in chain is the Lighting relay, feeds rear light, and supplies power to main FR and dip DR relays. Battery to MR and other relays, 3 Blue brown wires, one to each fuse block, Control fuse, lights fuse, rest fuse.
MR has a heavy white feed to, FR,, FR heavy blue / white feed to main beam, DR gets a blue feed and has a blue /red to dip beam.

Showing oil tank breather , now vented to catch bottle in LHS panel
[Linked Image]
Working at lamp bucket, it has a mini dipping relay in it and the flasher relay is behind the headstock.
[Linked Image]

Lights relay located in air box on old zener diode mounts.
Only the FR uses a relay base, space restrictions mean these are a good idea but too clumsy for the other locations.
[Linked Image]

Mini dip relay on velcro in lamp bucket.
[Linked Image]

This is day two of wiring, and I have run out of 3 way connectors, needed for sub tank connections.
.Sooon come.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 06/17/16 7:02 am

Work ethic upgrade,total abstinence from social contact , An hour in the morning is worth two in the afternoon,plus two cups of heart starter strength coffee, and bonus feature, witchcraft.
You know that point in a project when everyone iss asking, Whens it going to be finished?
and you look around at the burach of dismembered stuff and think, hmmm, maybe never...
I always reply , "by the end of the month ", not specifying which month, of course.
Its at times like this that Ju Ju can be fairly useful. From my mojo bag I select
The 40 knot string.
This is strong magic. To use it simply pass one knot from one hand to the other, 40 times. Each time wishing for the particular success desired. I only use this for BSA rebuilds, not wishing to dilute the effect on schemes involving raw greed or even goodwill.
Its working, after 3 days since using this mental rehearsal, I am know frazzled from ghosters( working 24 hour shifts) but the loom is semi complete and functioning. Core wiring is complete , all relays work, lights, ignition etc. only rear lamp, brake switch and horn to finish.
Other tools used so far.

I now have a grudging slightly greater respect for professional sparkies, about 4 hours work took me 3 days, wrap ,unwrap, reconfigure, re wrap, crimp the wrong thing, forget the insulation sleeve, unwrap, re wrap ad infinitum.

Some stuff that was handy.
[Linked Image]

The mark X wiring diagram, with deliberate error ( missing ignition switch). With various crimps, Jap bullet style, ring terminals, heavy for battery lugs, a relay, fuse holder and base, and just peeling in a wire stripper.

Digi meter, used for volts and ohms , very handy. Jap bullet assortment selection box.

[Linked Image]

Outer circle to inner.
The 40 knot motivational ju ju string.
PVC sleeving , 3 diameters, 2 core, 4 core, and extra large for sleeving handlebar switch wires(not shown)
Loom cloth, self closing style braided.
Heat shrink and adhesive velcro.
The tape roll is that magic stuff for binding looms, I found it much easier to use in one foot lengths, wrapping from the roll is too sloppy.
[Linked Image]

No cable ties were used for permanent stuff, I did use some to loose tie the loom before sleeving it.
The spine section of the loom only carries 5 cores, it gets busy under the headstock as the White "hot wire" from the main relay splits 4 ways, , live to FR ( Flash main beam relay), live to kill switch, live to flasher/dip switch,and live to lamp bucket light switch.
I have tried to match the original loom colours for switch control wiring.

The 5 cores are. Caps are heavy feeds, Lower case are relay coil control wires.
RED earth .
WHITE hot live from MR. to FR and White switch controls.
BLUE, lights feed to DR ( Dip relay) in lamp bucket
White/ yellow, supply from kill switch
Blue , control wire from Bucket light switch to LR ( lights relay in air box).

5 Lamp bucket loom cores. ( excluding Clock lamp wires, which do not pass round the headstock.)

White, hot live to light switch sundries.
BLUE power feed to DR
BLUE/ WHITE from FR to main beam lamp.
Blue /red control from bar s/w to DR.
Blue, light s/w control to LR.

Handrebal switch cores.

White yellow, kill switch.
White, live to kill switch.
Redundant indicator cores in place but sleeved. may use as light Main / pilot switch one day.


White, live to horn and flash switches.
Blue , Dip Light s/w control feed
Blue White, FR control.
Blue Red, control to DR
Purple/ Black, horn feed ( not through a relay , I know, but its a small horn and I never use it except for the MOT), can be wired to FR to sound when flashing lights,but that may annoy me. I am a silent flasher, fnarr fnarr.
Coming soon, the MK 12 Brake switch/ pedal interface. Maybe this time.

Posted By: Andy Higham

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 06/17/16 11:23 am

if you know someone with a RS account,they sell some useful double sided velcro (it sticks to itself). It is ideal for tying wiring to the frame
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 06/17/16 2:01 pm

Cheers Andy, I had some in a box of cable tidy stuff from lidl. Ive used it to nip up the rats nest under the tank
Commissioning snags, LR was miss wired, easy fix, read the numbers on the back properly.
Dip was weird, fault found in dip switch contact arm, bent spring blade to repair. Now AOK.
Horn works too. All front electrics complete, brake s/w and tail still to complete.
Front end work in progress.
Stanchions drawn into to top yokes with old steel top nuts, . Yokes completed . Deciding on fork spring length, as first fitted with the 50 mm shortening spacers in, I had 28 mm of spring poking out of the yoke, the top nut gives a further compression of 15 mm pre load, total 43, too much to allow assembly.
The spring has already been shortened by about 4" so is now in effect stiffer, I dont want to chop any more off to shorten it and increase the stiffness.. If I need more preload after testing I can add in a shortened stroke reducing spacer. Sock travel is probably a good place to start from anyway.
Also noted pre load adjuster range is limited to about 4 mm due to clearance issues with the handle bars , which will get worse when the clock bracket is fitted.
Took out the 50 mm stroke shortening spacer, re assembled ( forks will be full stroke 6.5 ") like this I have a wee bit of preload when the top nut is full home, will fit seals now and fill with oil. This setting will do to begin with. A PITA because to reach the damping centre adjuster I will need to take off the bars. Clip on time maybe( dont have any decent ones though). There is a pretty scabby set kicking around somewhere.
Engaging the telescopic square section damping adjuster, I found that I could feel for it if I gently lowered the top section down the spring, when I felt it stop at the top of the female square section I twisted the top square rod gently till it slid in, you can tell its in by the drag of the needle valce adjuster as you turn the top nut. Phew.
its good to be working on big stuff for a change.
Posted By: kommando

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 06/17/16 2:36 pm

If the preload is an issue I can do a pair of new fork nuts with the preload load adjustment internal and no extension coming out of the top, it will have a long threaded extension to fit iside the spring and 2 half nuts to lock to each other so you can adjust preload, a new problem then would be you could be back to the nut needing to be pressed down before it can be engaged with the thread in the stanchion.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds+ forks A65 750 1971 - 06/17/16 9:01 pm

Its not a massive deal, the bars come off with two nuts , so I can live with this at the moment, I have fully assembled the RHS ,
Fork top nut detail.
I fitted a 7/16" ID washer, located nicely over the centre register and cleared the adjuster nuts, between the spring and the top nut to prevent the spring biting the adjuster. deleted the previously fitted Dowty , which didnt do much, but did stop oil leaking out of the top nut once , years ago, I had fitted it for a reason, British bikes eh, even the top nuts leaked. under the Speedo bracket flange , and the chrome washer above the speedo flange, to gain a little more pre load.
Thinking maybe a half inch of spacer under the damper as an option if there is not enough pre load as is..
As fitted I meet resistance as the fork top nut is engaged , pretty similar to the old saggy set up. But now the spring rate is higher.
I have set the damper adjuster at 5 turns out from closed. Filled with 190 ml 10 W oil. Stock volume. There is no pre load adjustment left as fitted.
Currently picking through Grin's Triumph site for some chassis parts, he has some cool stuff.
Discovered that there is a wonderful thing, part number 83 - 4086 , read and weep with joy, a captive nut for the head steady mount, this will improve my life quality more than you can understand. This mount has kicked my ,,,, in, so many times.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds+ forks A65 750 1971 - 06/19/16 5:57 am

More useful tools, this cheap crimper is very handy,
[Linked Image] I did most of the ctimping usingt this, I have a spring ratchet type as well but it is a little clumsy for getting into tight corners.

Various shots of under tank stuff, horn and flasher relay.
New lamp bucket and stays, shiny. Also flimsy, noticeably lighter than the original.
[Linked Image][Linked Image][Linked Image]

Fork top nut/ hbar interface
[Linked Image]

Front end done
[Linked Image][Linked Image]
Fuses under seat, easy access.
[Linked Image] Just discovered I am short of two dimpled washers for the P bracket bar mounts, been fitting them wrong for years!
Posted By: gavin eisler

Re: alloy barrels + 5 speeds+ forks A65 750 1971 - 06/19/16 12:42 pm

Fork mod info, 80 mm chopped off old spring,partly due to length restrictions , the new hi speed / low speed bit takes up some room ( 30 mm approx), and partly because I wish to shorten the stroke a little to give a lower ride height front end and give more bearing surface for the sliders to run on, stiffening the legs up a bit.

Spring rate, Trimmed 80 mm off the springs , rate now approx 29 lb/ inch up from stock 24 lb/inch, based on spring turn numbers and wire diameter sums. about 20% stiffer.

My sliders are worn, RHS top area is not pretty , but didnt leak before.

Kommando supplied 50 mm spacers to shorten the fork stroke, these fit beneath the damper piston in tandem with the rebound springs. Planning on cutting these into 2 x 15 mm and 2 x 35 mm to give two possible pre load/ fork stroke reductions depending on pre load requirement, anything else will mean a new set of springs. Early days yet, will see how this goes.
In theory the improved hi speed damping allows stiffer springs, the older fixed hole type would lock up as travel speed increased effectively creating hydraulic lock bump stop on compression, as stock the system is undersprung and over ( hi speed) damped.
Thats what I reckon anyway. I will start with minimum low speed damping settings, and note effects as they are increased. There are 6 turns of adjustment on each low speed screw, hi speed damping changes will mean stripping and changing shims. Nothing too tricky tools wise, one Allen screw and one nut means a fairly simple strip, fork seals are cheap, better get a set of spares in.

Will shoot for 30mm static sag once I have the bike assembled.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds+ forks A65 750 1971 - 06/19/16 1:12 pm

Some wiring notes before I forget.
The Boyer and coil connections are not part of the loom, I dont want any parallel runs giving noise to the ignition, like wise the reg rec is not in the loom, and can be removed without to much trouble it has its own discrete earth and battery tails.
Earths, all components have their own earth wire connections back to a common bus earth running from top to toe, the chassis earth is bolted at the rear coil bracket/ mudguard mount, and the motor is earthed at the head steady mount ( a new thing).
In the lamp bucket two 3 way connectors tie in the 2 x idiot light earths, the dip relay earth and the main lamp earth. I have not used the lamp bucket earth tag electrically, it is a pretty handy guide loop though.
Relays, I used 3 types, the main is 50 amp and the feed terminal is a 10 mm blade, FR and LR are stock 4 terminal 30 amp relays, and the Dip relay is a "micro relay", only FR has a fitted base, the others have tails straight to the terminals , due to space restrictions.

I have wired the relays with a switched live to the coil from seperate pilot supplies. Each relay coil has its own earth connection to the bus earth.
If a switched earth is used to operate the relay coil then fewer wires are used since the live feed can piggy back to the control coil. However its considered bad practice to switch earths for control, any shorting to earth with this method can cause mayhem.

Loom spine has 4 tails emerging for LR at the airbox RHS, 1 earth at the headsteady and 5 connections under the front of the oil spine.
The loom is trapped between airbox and spine, then velcroed in two places to hold it in place along its length beneath the spine.

The Lamp bucket loom and the bar s/w looms run through PVC sleeves before passing through the frame grommets, previously only the bucket loom was sleeved.
A new slightly larger , much louder, red horn is fitted.

All bar switches were opened up, I like this Lucas switch gear!, its chunky and it has decent quality contacts fitted, the wee pads were still in very good condition, I drew some 600 grit paper through all sets while I was in there. The dip switch gave me grief, I thought at first I had the wrong rocker fitted, but after swapping for the indicator rocker I realised my mistake, the moving contact for the dip circuit was barely making, a slight tweak of the spring blade was the eventual fix. For 45 year old switch gear its doing very well.
There is an option to use the RHS 2 position rocker as a pilot/ main light switch. I have no pilot lamp at present. Also planning on LED instrument lights to save 9 watts.

Lighting, currently I have a 40 /45 QH main beam, trial fitted a Cree push bike LED spotlight , it is easily 4 times brighter than the main beam. Its battery pack straps to the frame down tube and will last 2 hours at max output, it has a half output and strobe setting. Unfortunately the button must be pushed 4 times to cycle from full through the other options , so switching it as a main beam is an issue. I tried leaving it on main beam and pulling the power socket, ( to see if switching the power supply on off could be used for control) , but it doesnt stay on and needs the button pushed once after reconnection , so that wont work. Any one hacked on of these? if I knew which components did the trick stuff I could just remove them?
On with the rear end now. Almost there for the chassis.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds+ forks A65 750 1971 - 06/22/16 3:14 pm

The return of the long black things.

Chainguard refitted after tapping out the front mount back to 1/4 UNF from whatever it had become when the DCo fitted an incorrect bolt in haste.
Spent a lot of time on the brake switch mount, getting the spacing right was tricky. Have ended up with 3 bits of 3 mm flat bar welded together, the lower section is 6 mm thick plus 3 mm to striker arm centre plus the nylon top hat bush rim about 4 mm to give the correct striker distance of 12 ish mm from the switch mount. including the 3 mm offset of the top cross bar Switch mount. It works with no added washer/shims to drop , but its all a tight fit.
The bracket has cost about 12 man hours, first one I made, got welded up, was inside out and back to front, . This rear set / switch set up is approaching the final iteration, I can feel it.

[Linked Image][Linked Image]
This allowed me to complete the wiring to the back end. Tucked the lamp wires in PVC sheaths under the mudguard and pinned them in with a couple of P clamps. Rear end is much tideier now without the big breather and ora wires.

[Linked Image]
[Linked Image]

Spent ages refilling the old grease gun, if anyone knows a simple way to fill these please tell, getting the air out took ages, any way swing arm and instrument cables are lubed up.
[Linked Image]

Wiring is complete , apart from stator connections its all good to go ,tested and operational
Tank as received from Scott Robertson the local painter guy, I asked for the same red with a silver under coat and to bury the decals in top coat. 200. Looks good , maybe bigger decals, but it'll do.

Below right see a 50 mm tube cut for the mounting rubbers set up.
[Linked Image]

Mounting rubbers minus tank,this is a Triumph tank from an uncertain later year this combo seems to give the best results, the tank has an internal flange which locates above the lower single cone , with the double cone and penny washer going on top, the 50 mm long x 5/16 ID tube passes right through and allows about 3 mm compression on the rubber when the washer meets the tube. The crappy pattern mount bolt and nut have different threads!, the bolt is 5/16 BSF, the nut is 5/16 UNF , when tightened against the tube everything is nice and firm with no clearance problems, phew. The lock stops were welded up so the forks cant clash with the tanks anymore, the old ones had lost about an 1/8" each side.

[Linked Image]

I used a wee diamond burr to open up the tank mount saddle on the frame, the new bolt is a snug fit now. this system worked before , except the top rubber was a single cone a nd the clamp bolt and spacer were shorter, the double cone now fitted is more secure with a greater area of ODh. Before fitting the nut there is about 10 mm of thread protruding through , enough to work with easily.
Tank fits with no fork clash , yay!
I havent repainted the shocks, dont see the point , no point in kidding on they are new, I imagine they will be replaced soon .
I have lost one of the handlebar mount cup and rubber, its in the room somewhere, running out of jobs to do before it turns up.
Fitted new switch gear screws , 8 off no10 UNC x 5/8" SS SHC screws, chewed up Phillips begone.[Linked Image]
Its been a fun day, big stuff going on looks like progress.
Tapped out the 5/16" UNF tank strap holes to get rid of paint.
Tested the strap clears horn, just, may fit a different horn bracket to centre it in the horn cutout.
Sorted some oil hose stuff out, need a cunning plan for the rocker oil feed ,
[Linked Image] the apres filter return line starts at 10 mm ID from the filter head , 10 " of 10 mm pipe to 10 x 8 reducer , 8 mm ID pipe short section to 8mm T piece, one leg to tank the next to rocker see crappy pic, the steel pipe is a loose fit in the 8 mm leg, would epoxy be OK, seems to loose to solder? May turn up an adaptor.Comments invited. Addendum, have nixed this pipe arrangement, rocker feed will probably come from the spur of the tee so that the main line to the tank is straighter, need carbs in position before final pipe runs. A 4mm to 8 mm adaptor seems like a better solution maybe , thats a lot of pipe clips ,13 in total this way, cant have that, "I aint superstitious, but a black cat just crossed my path" as Mr Burnett once said.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds+ forks A65 750 1971 - 06/24/16 4:55 am

A few more shots of the tank showing mounting hardware and brace strap.
[Linked Image][Linked Image][Linked Image]

Rocker feed take off, possible final location.
[Linked Image]

Time spent on reconnaissance is seldom wasted. So a last dummy up of fitting the cases, a word to the wise.

IMPORTANT info for A65 motor installation.

Fitting the Drive Side engine plate loosely to the motor before installing with the all important lower motor mount bolt is an essential part of installation. Screwdriver points to the critical bolt. This will save much wailing and gnashing of teeth.
[Linked Image]

Checking brake pedal travel, its close but I now have an acceptable 50mm of pedal travel , should be enough, fitting a couple of washers to the inboard side of the silencer mount won 5 mm of extra travel, its the first bulge of the silencer that causes the conflict, one last job is to fit an anti rotation pin to the brake switch mount, thats what the masking tape is for in the pics, marking up alignment before drilling.

Pedal up

[Linked Image]

Pedal down.

[Linked Image]

The old bit of ally mudguard is to be cut down to make a rear lower extension, might help keep the crud off the oil filter. Note the magnetic tool rack on the bench leg, a recent addition to help clear the decks.
[Linked Image].
Thats almost it for the chassis, apart from mounting the seat its all onboard. Motor build soon.
A notable feature of this rebuild is the shear amount of plastic waste I have created, a bag of plastic bags is now bulging, does everything really need to be double wrapped in a symbolic placenta?
Posted By: Ger B

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 06/24/16 5:57 am

Time spent on reconnaissance is seldom wasted

Wise words, Gavin.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 06/26/16 7:31 pm

Solved the rocker feed, cut two barbs off the spur , tapped it 6 mm, drilled a 2 mm hole lengthwise through a 6 mm bolt , cut the head off , stuck half the length in the drill press and filed it down to 4.7 mm , the same OD as the feed pipe, shortened the rocker pipe the required amount and done. The drilled out bolt will be glued into the the threaded spur on final assembly, all oil lines now done. All of the adapters live between the carbs, and to stop it looking like a pipe clip factory explosion I used crimped hose bands for the more permanent joins.

Parcel from Grins arrived, sorted for tank sump gaskets ( havent looked in there for a decade or so. Could be interesting!), and the excellent captive nut for the headsteady plus a few bits of handlebar furniture. And a weld on side stand tap, it looks pretty chunky. Will post pics in the morn.

Took the centre stand to the smiddy for straightening and shortening, it should be ready this week.
Cases next.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 06/27/16 7:27 am

Rocker feed , cut down head end, 6 mm adaptor shown,

[Linked Image]

Screwed into tapped spur on 8 mm Tee fitting
[Linked Image] the manifold pipe is cut and plugged with an Amal throttle stop screw, should be handy for oil changes.

Weld on side stand tab from grins.
[Linked Image]

Trapped head steady nut, 3/8"th UNF.
[Linked Image]

Two options for tank mounting, home brew below, Option two from Grin above, this is a nice piece of kit, comes with a toothed washer to trap the tank bolt in situ, the bolt end has a good lead in for the nut, I like it, also comes with a cupped washer to locate over the rubber, its simpler than the home brew, presumably the cone rubber goes above the tank flange , wide end down?
[Linked Image]
[Linked Image]

"Grin" has a good stock of quality Triumph stuff, he is in Scotland and doesnt do phone calls, web site and part numbers is the way to go, very handy for a lot of fiddly wee bits. Not been disappointed with this guy.

Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 06/29/16 9:31 pm

A big day today, crank assembled with a rub down, assembly fluid applied to big ends, ( which is gloop that smells strongly of gear oil mixed with grease) , never used this particular stuff before, normally engine oil.
[Linked Image]

The old shells were pretty good, the DS showing more pick up than the TS, nothing drastic. About 10K in on straight 40. Note the DS conrod has oil holes on each side, 1970 rods. New shells at -20, crank radiused, ground, balanced, and chamfered from SRM. cleaned with thinners after tape removal, new -20 thou shells, and ARP big end bolts, torqued 3 times plus loctite to 28 ft lbs( as per SRM instructions, these are very detailed and mention that BSA alloy capped rods will benefit from reaming after torque up in an ideal world) if using with steel end caps torque goes up to 30 ft lbs.
[Linked Image]
These bolts were ticht compared to the originals, nut sizes are different, old bolts , nuts 1/4 BSW, head (larger), new bolt/ nuts 1/2" AF, cleaned with thinners before assembly.. Cases are ready with new TS outer. The cases (already hot from pre wash) took five minutes in the oven at 200 C to drop the old outer, new one dropped in at -18 C from the freezer.
The ^TS inner sleeve remains as previous, the sleeve is fitted for the correct end float, the new one was about 2 mm longer ((probably more) , the existing inner sleeve shows no measurable wear and is fit , so after a test spin I am a happy boy with this.
Cases have had a doing from a conical diamond burr around bush oil feed holes and a few casting snotters that acted as oil dams have been nixed. other than that and a bit of flange dressing they go back as stock.
Pics in the morn.
New DS seal fitted and gearbox seal, tools used with old mains.
[Linked Image]
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 06/29/16 9:52 pm

About the con rods, by 1970 BSA had beefed up the rods and taken the trouble of shot peening them, the rods fitted are 1970 items recovered from a low mileage motor which had blown the gear box casing from a snapped chain circa 1972, they have done about 10K in the motor so far, and havent seen 7K more than 5 times, a few miles left. I selected these as the best matched heaviest pair from 8 possible contenders, including the as found (polished) items, which were out by a few grammes. The constant paranoia of a rod letting go hasnt got to me yet! One day a Nourish crank and Ultra/Mega / Giga rods will come my way, but not yet, stock is still trick.

Handling the crank I am struck by what an awesome Gyro it is , unlike any modern thing, it has a relatively huge mass plumb in the centre , and it weighs a ton. Maybe, this is where that " on lines " feeling lives.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 06/30/16 7:33 pm

Assembled the crank and fitted it to the cases.
[Linked Image][Linked Image]

Fitting crank brg. after a trip to the oven, the water glass is a gill container from an old still site, its holding the bearing in while it warms up after a stay in the freezer.
This pic also shows the opened up oil drip holes for the cam bush, all bush drippers got this treatment.
[Linked Image]

Wellseal for crankcase joint.
[Linked Image]

Mr Harris helped with fitting the cases into the frame, nae bother.
[Linked Image]
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/01/16 6:09 am

A note about the timing side ball needle combo.
The crank is located axially by the ball bearing, its position is determined by the length of the brg inner sleeve, these are/ were modified by SRM/ Devimead , by 3 grinding operations.
The sleeve is shortened , internally radiused to match the crank and two bevels are created 180 degrees apart so the sleeve can be pulled off. The exact amount to be ground off the sleeve length is particular to each motor.

Bottom engine mount , a washer is inserted on the drive side between frame and case to take up clearance, this was missing previously. Not an easy thing to fit in but its done now, awaiting a silky smooth transformation, between this , and the repaired worn DS shaft journal and the dynamically balanced crank .

The next fiddly job is to repair the OPRV oil strainer which is ruined, I bought some pipe screen filters in town for 50 p , lets see if I can make these fit.
Posted By: Allan Gill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/01/16 7:47 am

TSS still has some NOS oprv units. Not expensive either. Although they weren't... The dollar to gbp exchange rate has mucked things up
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/01/16 8:09 pm

Thanks for the tip Allan, solved it with a 50 p packet of crack pipe filters from the local pet shop .John Bells in Oban has weird stuff, trimmed the brass mesh down with a wee pair o scissors, opened up the crimped rim with a knife , worried the new mesh in then crimped it back with a 1/2 AF socket, you need your specs on for this. Valve body, new filter in crimp , old filter.
[Linked Image]

The filter screen is backed by a washer which prevents the piston from hitting the screen, I had to open up the swage on the valve body where the filter locates using the ring end of a 1/2 " AF ring spanner, spot the trend eh, to get the washer back in,somehow it had grown , or the swage had been knocked back. With the washer and filter in place I remade the swage with a small brass hammer. It all went together well with fresh annealed Cu washers between dome and cases.
[Linked Image][Linked Image]
[Linked Image][Linked Image]

I used Permabond A131 pipe sealer sparingly applied to the female inner threads behind the relief hole, and a touch on the outer male threads of the valve body, all torqued up and done.
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Started on the valve seat pockets, took the diamond burr round the seat to chamber zone to make the lip vanish. The valves had to come out for this , nerve wracking stuff. One side is roughed out , got tired and stopped.
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Should finish this tomorrow, then port filling, will D the ports again, with more this time.
Posted By: Allan Gill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/02/16 3:04 am

If your D shaping the ports, having a final roof height of 20mm gives the best flow whilst still being able to carburate. You can go smaller still with good results but getting the jetting lean enough is a challenge.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/02/16 7:46 am

Thanks for the tip Allan, will push on with this today. I have a couple of options for filler epoxy.
Surf board repair stuff, mixes 2 parts filler to 1 part hardener, also glass micro beads to act as a filler. or typical two part Devcon in one oz tubes, or JB weld which I have never used before.
The surf board epoxy is pretty runny when mixed, but I have about 2 litres of this. Any thoughts.
Posted By: Allan Gill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/02/16 8:16 am

Both my self and mark parker uses the JB weld. It takes some working to get to shape once set but I can confirm that it is not effected by the fuel.

You MUST, sand the port first with one of those little flap wheels on a dremel and add little crevices into the port floor to act as an anchor point. But do that and you won't have a problem and it will stick like [***] to a blanket. I tried one without doing that prep, just gave it a good clean, but with a pick with a screw driver I could lever it out after.

Worst thing that happens with the JB weld is it stains brown but it doesn't effect from fuel.

For jetting start with same slide, 105 needle and needle in lowest position and stick with same main jet. You may end up coming down two or 4 sizes with the main jet.

The first head I modified had some filling after the guide, it went well but built in a Rev
Limiter at 7200 rpm and meant I had to drop from a 250 main jet to 210. You certainly won't need to go richer. But remain static or go leaner. Sometimes the slide could do with being richer. Which I have yet to understand why.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/02/16 9:44 am

By lowest position, do you mean the lowest groove , ie rich or physically lowest , top groove ( lean)
Posted By: Allan Gill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/02/16 2:04 pm

Sorry, position 1, top notch, leanest setting.

You will find it will pull from nothing. And rev harder then it does as standard. You will also find that if your in the wrong gear, the torque will be better to still pull you through it.

The mega cycle x12 cam that I initially bought for my racer went into my road bike. It makes for an excellent combination and gives it a lot more punch than the standard cam without being radical.
Posted By: triton thrasher

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/02/16 2:31 pm

On any new setup, I wouldn't try the weakest needle position first.
Posted By: Allan Gill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/02/16 5:06 pm

Not normally no. But if you follow what i have mentioned for the porting then you will find this as the richest you will want to go. I have found on some occasions I have needed a fatter (Norton) needle.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/02/16 5:08 pm

Good point TT , I will sneak down to it. Tidied up today , sorted out my spanners, I have too many metric spanners and not enough AF, the tool imps have been in. Still looking for the handlebar top P mount rubber washer cup and spacer which are winning at hide and seek for the tenth day now.They are in the room, Ive had a "boy's look ", and a slightly more mature search, going forensic next.
Posted By: kevin roberts

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/02/16 5:43 pm

Originally Posted by gavin eisler
. . the tool imps have been in. Still looking for the handlebar top P mount rubber washer cup and spacer which are winning at hide and seek for the tenth day now.They are in the room, Ive had a "boy's look ", and a slightly more mature search, going forensic next.

i have my own colony of the good people in my shop. i spent an hour looking for a radiator hose i've been cutting up for carburetor spigot mounts, and never found it . . .

had to cut up a perfectly good new one i've been keeping for a spare for the truck.

i'm going to start leaving out a saucer of milk a few days before i need to do anything important.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/03/16 6:09 am

The tool imps really had been in, I have had a lot of drilling to do lately, and the centre punch had gone on vacation, nowhere to be found, ended up using dry wall screws to dab marks!, turns out my sons friend Tom had " borrowed it " he is now banned from the BSA room. At least he returned it, if he had told me he had borrowed it at the time he might have escaped a ban.

Just checked the inlet ports behind the valve guides, used "jenny leg" calipers vertically, 28 mm LHS, 27 mm RHS where I had epoxied previously, the LHS epoxy had disappeared in the SRM clean up..
Not too great a fill. will attempt to work out approx volumes in CCs required
will one set of JB , ie 2 oz total be enough for both sides?
Posted By: Allan Gill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/03/16 8:17 am

Might only just be enough. Will be worth getting two. Bought the jumbo size and did 3 heads with that. Although by the time I did the last one it was starting to go off grin
Posted By: shel

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/03/16 11:08 am

Following with interest, Gavin, even though I don't own a BSA.
I have a black hole in my shop. I'll drop a small widget, watch it hit the ground, see which direction it bounces and a couple minutes later we I go to retrieve it it's just vanished.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/03/16 5:34 pm

two steps forward one back, rebuilt the oil pump . went to fit it , once the crank pinion worm was nipped up the crank went solid. Motor back out, TS bearing coming out for measurements, correction, Clung !, its out, just fell out of the oven while typing, the old one is 26.94 mm long axially. The still hot new one is... pause to fetch guessing stick, ..... the smell of freshly baked cases hangs heavily in the air, 27.06 mm , 0.12 mm larger . Should have spotted this on pre assembly checks, they didnt happen, just dropped in the bearing while the cases were hot from the old extraction. Should be able to stone this off , there are some obvious clues, the crank shows a shiny contact patch on the cheek and the old brg has no makers script on the inboard face , unlike the new one. 0.12 mm is about 5 thou" in real money, thats do-able by hand on the oil stone.

Pics of oil pump assembly and gaskets.
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The blue thing is the shop air compressor, its a double acting single cylinder , solar powered watchmakers model, almost silent in operation, I hate it when the clattery garage things kick in, it always makes me jump.
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Trying gaskets for size, found an old/ new black one, measured it up against the SRM latest,
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[Linked Image]
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although thinner the new SRM gasket is much more accurately made, worst case scenario with the old one had half the ports semi blocked,

[Linked Image]
the new one got a little clean up with a wee round file but it was pretty good.
the new one is blue on the other side.
[Linked Image]
Next installment, tedious lapping.
Iceland 2 England 1 at the footie. Brits to leave Europe , financial collapse, weird times, better get on with it.
Found a factory manual anomaly, 1970 manual gives 5/16" OD as the pump NRV ball OD, the 71 factory manual gives 1/4", I had a quarter ball fitted before..
Looking on the bright side , I hadnt fitted the top end, and all the tools were readily to hand, after getting over the original scunner it was back out in about an hour, not the worst setback, not compared to the 20 man hour brake light switch.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/03/16 8:18 pm

lapped down the new brg. looked closer at the old brg. Of course you cant fit the new outer to the old inner, stupid boy!. The new brg has the ball race set further outboard than the old one, trying to draw the crank up was pulling the short old inner sleeve in far enough for the crank cheek to say hello, old sleeve must come off, naive of me to think I would get away with this. Will lap the new inner sleeve so the stack heights of the complete brg.s are equal, after removing the old inner.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/04/16 10:51 am

Borrowed Ali's puller set from the LBS, thanks Ali, ground up a wee chisel, heated the TS sleeve till it bubbled goo round the base, two deftly aimed whacks with the chisel at the pre ground inner bevels, and the sleeve lifted enough to get the drawing gear on,. off in a jiffy.
Checked stack heights/ length overall as close to a thou equal as I can make out with the guessing stick and my granite surface table, need to radius the sleeve inner before mounting. pics soon.
Posted By: Allan Gill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/04/16 2:23 pm

Yes I put my inner sleeve in a lathe and attacked it with a belt sander. Did a lovely job.

Interestingly. When devimead did my original crank they didn't radius the journal they just ground it square. Infact they ground everything square.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/04/16 2:55 pm

my original sleeve had an internal radius, larger than the new one, just spent an hour correcting its radius, and getting the final overall length of sleeve to thrust collar end down to 1.177", same as the old one , had to stone about 2 thou off the new one. Case back in the oven for refit.
Looks like the old sleeve was fitted with loctite , now the journal is clean the new sleeve is a tight sliding fit , will dry test before final loctiting.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/04/16 9:47 pm

Pics of crank work,
Brg inner sleeve internal radius,
[Linked Image]

old and new showing different thrust collar height and ball stacks.
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Brg inner sleeve internal radius,
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Chisel used to shift the sleeve initially, heated sleeve first with blowlamp

Pulling gear
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used a 400 grit diamond lapping plate to take a couple of thou off the sleeve length, tedious, one 3 minute blues is worth about a quarter thou, less than a whole album later it was done.Stack length within a thou of original and outer bearing width corrected the same.
[Linked Image]

First fit of the sleeve with blue, showed a couple of marks on the inner radius and didnt quite make the cheeks, a 1 thou feeler would go, dressed the high spots, second fit would trap a cigarette paper, , if it was any better it would be no use at all, blue all round cheek where the brg seats..
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Test assembly TS brg and crank pinion with nipped up , spins lovely , job done.
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Crank case re assembly, wellseal drying.

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Torqued up to 15lb ft on all 5/16 fasteners after truing with barrels and good to go.
Midnight oil has been burnt. Must return the pulling gear tomorrow

Taking pics through the lamp lense gives an easier focus for close up, handy.
[Linked Image]
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/05/16 8:22 pm

Fitted the oil pump and sump plate, easy, fitted the idler pinion and cam pinion,, it all goes tight for a 1/2 rev of the idler pinion, hmmmm,checked it wasnt the oil pump, back lash at the idler/ cam pinions, no back lash at the crank / idler mesh. Not solid , but resistance noted.
looks like the idler pinion is eccentric, heated it up and removed it from the shaft, need to find another one, this may have been ok with the old worn bushes or, possibly, when the pinion was pressed off the old shaft it galled , I can see one side has picked up internally, perhaps this is throwing stuff off.
Its the same 1/2 portion of the idler each time, so its not the crank pinion and theres back lash all round at the cam. perhaps when the bushes were line reamed the new centre was a smidge over to the crank . Any way a true pinion should fix it. Or , worst case scenario , if that doesnt work , then then it all comes apart to fit new idler bushes as well, theres one thing for sure, the idler pinion is eccentric, so , thats the first move.I think I have one somewhere, or it might be a spare cam pinion, will search in the morning. I tried the old pinion shaft in the new bush, its tight?! too tight to turn! The new shaft must be undersized compared with the old worn pinion, another check that didnt happen, the bush gets sized to the shaft so no big deal I suppose ..

Wish Id left the old rattly bushes in, I am now fixing something that wasnt broken before, just a bit "free"//run in / shagged out. i thought it was shagged, but I am leaning towards well run in now. . Its a fine line between them. Thank fully the cam bushes were left alone , they have no play at all once assembled and spin beautifully..
Posted By: Allan Gill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/06/16 3:19 am

Well you were right to do it, anything eccentric would cause premature wear in the bushes and the timing. I have some cam pinions but no idler gear ones otherwise I would have put one in the post for you. But as long as you put the two cases together and ran the reamer through them both at the same time, it should all be in line and true. Leaving only the cam pinion to be at fault.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/06/16 6:26 am

theres nowt wrong with the cam pinion, it has backlash whichever position the idler is in,
its the idler pinion thats off centre.relative to its shaft. Calling SRM today for parts then off to Ireland privateering on Saorsa for a feed of Guinness and porpoise detecting. No BSA stuff for the next week, then a big wedding to got to in Alyth .

Called in at the Smiddy for a check on centre stand progress, it had moved about ten feet , from the welders bench onto a side rack, otherwise untouched. The welding team are doing nightshifts at Glen Sanda superquarry, if only the world didnt need new road metal it would have been done by now, Oh well, upped the urgency to " I need it yesterday" this brought a large smile to the smiddy guy's face , " I will pass that ontae Robert " , we both know what that means, bring on manana.
Strong Westerlies for the next few days should be a fun sail, whisky , black pudding and ships bannocks ready to go.

SRM, idler pinion gear , nil, but they do have the oil seal for the quill feed that got left out of the original order.. Draganfly, a choice of three used idler gears, the least worst is on its way after a good blether with Trevor, wonderful.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/06/16 8:49 am

Went back to it in the cold light of day, rotated the idler gear through 180 degrees so the keyways were opposite and fitted it back on for trial, the eccentricity is definitely in the gear , not the shaft, the error remained in the same chord section of the gear, if the shaft was out it would have moved 180.
With a more " the lights must stay on, mail get through " attitude. Nothing to lose etc.

Looked at the galling, polished it out a bit, shaft fit gone from tight press to nearly loose, symptoms improved , close , but no cigar, will wait for the new / old gear to come, not using a hydraulic press for this without heat again, lesson learned. I can see a bruised zone round the gear ID, it must have distorted under pressure before the shaft moved.


Will fit the wheels next to create an illusion of progress,and cheer myself up a bit, havent touched them so it should go well. need the back one soon for tightening stuff up. Getting a new chain from the LBS, 530 with no O rings is not very common it seems, some sort of Black DID thing is on its way, its suspiciously cheap..
Posted By: Allan Gill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/06/16 5:57 pm

I run the iwis mega life chain. It just lasts and lasts.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/06/16 7:26 pm

Last post for a while.

Galling on the idler pinion.
[Linked Image][Linked Image]

Rear wheel assembly in place,spent a couple of hours cleaning up the wheel.
Brake lever needs a final polish, you dont even see the 20 man hour bracket.
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Rear hub
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Scabby shocks
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Gear cluster assembles, even remembered the cam plunger before final torque up.
[Linked Image]
The new speedo cable inner is too small to turn the speedo, pattern junk.
Posted By: Adam M.

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/06/16 8:55 pm

Your last posts sound exactly like mine on the Trident ( nothing fits like it should ) smile.
Plus a fair share our own mistakes in the pudding.
Mine costed me a good few hours of work and lots of stress.
Have a good time next week.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/15/16 8:38 am

Survived the trip, Fairlie, Campbeltown, Ballycastle N. Ireland, Islay, Campbeltown, Loch Ranza isle of Arran and Rothsay isle of Bute.
Minimal liver damage and a few scars inflicted by brambles.
Waverly paddle steamer and deserted island hardware.

Apologies to readers for non bike content, but the old lathe was pretty funky. The Waverly stalked us around the Clyde, a beautiful thing.
[Linked Image][Linked Image][Linked Image][Linked Image][Linked Image]

parts came in the post
[Linked Image]

New steel pushrods, new/old idler pinion, crank end feed oil seal and a lot of 6 mm ID Cu washers.

A home made rocker oil feed cooler is in the pipeline, the washers will become fins. I never liked the idea of the return hot oil going to the head, Citroen built unburstable 600 flat twin motors, designed by Dr porsche ( 2CVs) that could be thrashed mercilessly all day long, they had oil cooling to the head oil feeds, worth a try.
Posted By: Ger B

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/15/16 9:11 am

Apologies to readers for non bike content

What your photo does not reveal: the two uptakes of the Waverly
are side by side. One for a SB-boiler, one for a PS boiler.
I love the anchor winch and that hook, shackle and ring. Very photogenic.
I was at a wharf the other week where a fellow was cleaning an
80 year old glow plug engine that had been under water for
fourty years. And d@mn it... no camera.
Posted By: Allan Gill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/15/16 6:12 pm

Those pushrods look like the chromolly ones SRM sell.

Out of interest why do you think the oil cooling to the head is the weak spot? As I'm sure you know the pre 68 (or pre 67 Y) motors had the rocker oil feed fed from the return pipe at the tank.

If by chance you have an oil cooler, fitted to the return line, what is to stop you welding/braising a pipe off the return pipe to the frame. Then you will have cooled and foltered(if you have a filter) oil to the rockers

Just a thought.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/16/16 6:14 am

Thanks Nick , your explanation of the return line over pressure might account for why I found the OPRV strainer popped off when I dismantled the motor, a large back pressure generated at the restriction in the return gallery would do this. I like the sound of your mod and the info on the oil diversion over 2,000 rpms , means this would be " a good thing", I will watch out for an older style OPRV and give this a try in the future.

Before , with cold oil the oil light would go out on kick over, but once hot it would flicker at idle, the OPRV as/is fitted has threads which can only be described as loose. This has been refitted with thread sealer carefully applied to prevent bleed through from HP side to dump side.

Alan, yup SRM steel pushrods,
I dont see the oil flow to the head as a particularly weak spot, but I would prefer if the hottest point of the motor was being fed with cooler oil, my cooler will only be in the rocker feed line, a small thing.
The proposed as currently fitted flow would be like this.
Existing oil manifold rocker line plugged, all return oil through the filter, then a T , one leg to tank one leg to rockers, thats the way its plumbed at the mo, the proposed cooler would go in the line between the T and the head. Too late to mod the frame return stub , thats painted.

Whats kicking my derriere at the mo is the idler pinion.
The new 2nd hand replacement has a subtly different shaft, longer on the crank side, shorter on the TS , possibly from an earlier model. A test fit and rotation shows its not eccentric "hurray" , but it is stiff all the way round, with no back lash at the crank pinion in any position, acceptable backlash at the cam pinion all the way round.. It would be nice to have a big box of these and do a bit of selective assembly. I may return this one and see if any of the other two that Draganfly have are a looser fit. i still havent changed the idler pinion shaft for the new one, the bushes were reamed for the fit of the new shaft which is about a quarter thou undersize compared to the old ones, barely measurable , but it turns freely in the new bushes and the old shafts do not. will try this first.
It looks like the inboard idler bush is possibly offset towards the crank pinion, this would account for all the symptoms . Strip , replace , ream, rebuild. Simple when you put it like that, the bushes are cheap, will get a new pair just in case. Full disclosure, my inner timing chest case has only one dowel at the top rear, its quite possible that when the cases were fitted up for reaming that the front end was a tad low, will get a hollow dowel to fit the crank end feed hole so that cant happen again.
Posted By: Allan Gill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/16/16 7:44 am

You really want to have the cases bolted together and line ream the two bushes at the same time. But for this you need the cases apart
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/18/16 11:51 am

Yup the motor may be split again, will try the new pinion shaft first .
Tools are ready to hand, its got to be right.
Speedo cable issue resolved with new outer , old inner, it was only replaced because of damage to the outer.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/18/16 7:57 pm

Well, the new / 2nd hand idler pinion is no better, its larger at the OD and ID of the gear teeth by about 4 thou. Part nos for this change for 71, have tracked down a 70 -9104 at BBB as opposed to the 68 1140 I have been trying. Will call them tomorrow. The older 68 number has a shorter outboard shaft,longer inboard shaft, the gears look the same but the dimensions are critically different.
learning all the time.
Posted By: Bodger

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/19/16 7:53 am

yer makin good progress actually, what a fiddly problem. Live and learn, and in this case share it, appreciated.
Just so you know, I for one love this thread and the few bits of off topic stuff are terrific, I love the Waverly, I could watch it going about all day, thanks for all of this..
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/19/16 8:27 am

I am glad you appreciate it, called Burtons BB, the nice wifie is on holiday, but the manny was just as helpful, the pinion should be here soon. Hopefully this should free off the pinion train.
The drive side is going back as was fitted previously, only new clutch springs and thrust needle roller for the clutch,this "should " be straight forward. Must get on with the head , and maybe get this done in the waiting time. Got other high priority jobs first, the Cagiva needs a new front tyre and an exhaust leak fixing.

The sound of the Waverly is very distinctive, the paddles are noisy, a fairly unsettling 120 BPM, it would make a good Techno rhythm backing track.

Other big engineering in the Clyde, Hunterston coal/ore terminal, big fenders and big cranes. now almost redundant, Steel no more ( Tories closed Ravenscraig, and coal no more, Global warming, Longannet and Cockenzie coal burning dinosaurs both shut for good)
Scotlands heavy engineering on the Clyde is almost over. Just the Nuclear weapons left.
[Linked Image][Linked Image]

I am told the big fenders are called "Yokohamas".

Posted By: JER.Hill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/19/16 8:53 am

Hi Gavin

Yes thats the general term, bit like "hoover" for a vacuum cleaner. First ones were probably made by the Yokohama tyre company back in the day.
Posted By: old mule

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 07/19/16 9:53 am

Thanks for posting your photos and especially the BSA information.
I almost wrote, "Thank you for doing the BSA development engineering that the factory forgot".
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 08/07/16 5:55 pm

Its been a sarach, the new old NOS 71 idler came from BBB.

It was covered in ensis fluid, washed it off, the pinion shaft journals were pitted, otherwise it was in good nick.

Old pinion drilled on left, old style , centre , new 1971 on right.
[Linked Image]
[Linked Image]
The journals were also oversized for the new bushes so I decided to polish them down to a running size. One of those throwaway sentences that completely fails to encompass how much pussing around this took. With no handy lathe I was forced to improvise, it took a couple of days for the penny to drop, while cleaning the idler pinion on the wire wheel the pinion wanted to spin between my fingers.
A light bulb moment, putting an old worn bush on one end and wrapping the other end in 400 grit paper then holding it to the wire wheel allowed fairly rapid progress. It gets hot!

This involved many trial fits, crank and idler, cam and idler , all three ultimately ,
as well as changing the idler pinion I also changed the cam pinion for a spare with three keyways to allow fine setting of the valve timing, the new cam pinion has not been drilled.

The 71 pinion is a chunky item, with more meat towards the centre, certainly a bit heavier than the earlier style . So its now a high inertia valve train, maybe thats a good thing?

It took many trial fits before I was happy with the free turning end result, by the time it was spinning like a peerie the new bushes with pinion fitted alone had a bit of wauchle/ looseness, there was no free spinning until then, there are still a couple of spots where the pinion will not pull free, other wise I am happy with the fit.
Along the way I learned a bit about how sensitive the cam is to the case pair alignment, if the barrels are not fitted before the case fasteners are nipped up then the cam wont turn, do the barrels first to align and its all copacetic and spins free.

I used this stuff a lot for final shaft polishing.
[Linked Image]
[Linked Image]
[Linked Image]
[Linked Image]

it gets finer , to 12000 for optical work.

So , bottom end re assembled , tighten crank worm to lock the timing side up, and, stiff turning crank, what? I thought I had fixed this, after much dicking around , head scratching and heading for a slough of despond I figured it out. After the last assembly when it was free to turn I had removed about 2 thou from the inner sleeve to make the overall length equal to the old bearing. Error. This allowed the crank to say hello to the bearing outer case.
In the oven, bearing out ( 15 mins at 150 C) more off the bearing outer, off with the sleeve and a 6 thou shim to move it out a bit from the crank cheek..
back together, spins fine no binding when torqued up. no pics either too scunnered.

Mounted back to frame , this time remembering the sump plate. Got a 20 thou washer on the TS of the bottom cases mount to frame. Found the oil pipes in the way and removed them ( they are too short as is ).
Gear cluster installed, remembered the index plunger, , tested OK.
New mainshaft outrigger bearing plate installed with sticky blue stuff , 6 X M6 screws and 4 x 2BA screws all with stud lock.

On with clutch work.
Many minor and some major defects.
The new needle thrust bearing , didnt sit well against the adjuster , the adjuster bearing face was like a ploughed field from the previous bearing failure. lapped up to flat on the diamond plate.

More later

Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 08/07/16 6:45 pm

Clutch bits, clutch hub, plates , pressure plate, push rod nedle roller and basket thrust washers.
[Linked Image]

Cush rubbers, springs , chain.
[Linked Image]

Dremellled off the clutch centre bolts dabs and un bolted the hub.

End plate wear , spider witness marks.

[Linked Image]

matching wear on spider arms.
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Clutch hub and relatively unworn top plate.
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[Linked Image]

Hub centre gap between plates.
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Spider thickness.
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Thats 20 thou" of wear. Or "knackered" in my terms.

new hub ordered.

Improved the clutch cup detent, so they dont cam out as badly. On strip down the cups had all spun and the dimples had been pushed up.The cut was out on a radius and slightly undercut.
Beat the dimples back in on the cups with a small punch.
[Linked Image]

Needle thrust pushrod adjuster after lapping the worst flat.
[Linked Image]

Same with needle bearing and pusher in position.
[Linked Image]

two different style thrust washers, the wassel item on the right is only 40 thou, the old one on the left is 45 thou, the one I will fit is a NOS I found in a drawer , its 50 thou. Wassel is not doing well here, its also bent and looks like its all copper.
[Linked Image]

High inertia valve train.
[Linked Image]

I need about 60 thou of spacer between the motor sprocket and the oil seal spacer to get the primary chain to line up with the clutch basket on the new mainshaft.
I test fitted the new clutch centre , basket , rollers and hub ( before stripping it)
[Linked Image]
because the spider and end plate are worn the clearance for the rollers has opened up , in the pic there is a small protrusion , roughly 25 thou of the spider hub protruding through the end plate, this allows the basket to tip wildly when the clutch is freed, hence the new hub on order.
[Linked Image]

The weird thing is, the clutch had been behaving very well. No dragging, maybe a slight slip when cold in 3rd going up hill.
Wear on one hub end plate and not the other is a new one for me, usually both are scarred up.

Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 08/08/16 5:21 am

After hastily purchasing a new complete clutch hub on line I decided to look for the two worn items, spiders are available but the inner end plate appears to be unobtanium, if anyone knows of a source, preferably in the UK. I tried using part number t1729 from the triumph 1971 book ( from a link in another thread), Grins site only does much longer part numbers which do not start with a T.hmm ,
Posted By: Ger B

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 08/08/16 5:33 am

Gavin, not in the UK but across the water, try:

He's away on holiday untill August 18th though.
Posted By: kommando

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 08/08/16 5:41 am


this may help T = 57

Before 1972 Triumph used a letter prefix and from 1972 onwards a number prefix.
The later system has the number prefix followed by four numbers.
e.g. E2879 became 70-2879 and T57 became 57-0057 etc.

These Prefixes are as follows:
14- Remains unchanged
S = 21 - e.g. S207 becomes 21-0207
W = 37 - e.g. W37 becomes 37-0037
T = 57 - e.g. T98 becomes 57-0098
D = 60 - e.g. D4026 becomes 60-4026
D1= 61 - e.g. D16020 becomes 61-6020
E = 70 - e.g. E7869 becomes 70-7869
E1 = 71 - e.g. E11698 becomes 71-1698
F = 82 - e.g. F6042 becomes 82-6042
F1 = 83 - e.g. F16468 becomes 83-6468
H = 97 - e.g. H3904 becomes 97-3904

Alternately turn the end plate over and drill 3 holes to make it a direct copy and you present an unworn side to the spider, depends if there is enough unworn bits on the worn side to operate as it should on that side.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 08/08/16 11:13 am

Thanks for the part no. info. i did find a place that has the end plates listed but they dont answer the phone.
"Alternately turn the end plate over and drill 3 holes to make it a direct copy and you present an unworn side to the spider, depends if there is enough unworn bits on the worn side to operate as it should on that side." i like your thinking, tragically the plates are not reversible, the outer face has a raised boss for the thrust washer to run against.

the new clutch centre complete should be here in a couple of days, John popped over with some shims and Forfar bridies ( McLarens natch) for the drive sprocket and left with oatcakes and a rocker cover, everybody happy.

Found some treasure in the attic, I have a spare end fed crank ( needs work though) and a plethora of worn clutch parts, with a set of half decent surflex plates in amongst the scrap pile.. woo hoo, .
Having a spare crank will allow a raised rev ceiling for the current set up.

Posted By: Allan Gill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 08/08/16 3:53 pm

How high do you want to rev Gavin? Mine sees 8000 plus regular and has yet to break.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 08/08/16 7:51 pm

Ive never revved it that hard before, it used to be pretty rough at high rpms, It has occasionally seen 7k but no more. I have a nasty "forces pressures and speeds " mantra that stops me .
Previous incarnations would spit out the exhaust pipes at over 5.5 K, that usually meant a half hour delay for fence wire bodge ups. Thanks to silicone and balance pipes these days are gone. I tried springs , pinning at the port , beer cans and all sorts.

One of the draw backs of 30 mm carbs on the 750 , great mid range, a bit restricted for top end. I have 32mms carbs on the shelf , maybe one day. it runs very sweetly at the moment so reluctant to change.
As an aside tell me about Newby clutches, do they fit on the stock clutch centre, or has it got a different bearing ? Do you need to space out the primary case?
I am not impressed with the stock clutch, the 3 legged spider is pitiful, compared to a norton it has at least half the load bearing area on the legs due to the tapering starfish design. maybe its because of the high first and slipping to get away but this part has a very short life sub 10 K miles with me anyway.
Posted By: Allan Gill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 08/09/16 7:57 am

Gavin, doesnt the John Hill 5 speed have a splined main shaft?

On the newby the inner and outer section are as one, but comprised of a large inner with a billion tiny balls, mounted within the basket - but as a user you never seperate this. the plates slide in and the lifting plate after that. 2x M8 bolts in a puller work for removing it. I even run mine without the keyway, torque to 100ft lb and never had it slip on the main shaft.

If it is splined, Keep an eye out for what PES are making to suit it.

I moved away from the standard clutch. I got it to work nicely in the end but i had already lost interest with it. I ran an srm lift plate and hyde 7 plate setup. it worked well until things started to wear again.

Once i get my Mk1 modifed (OIF) head back from having a plug thread done, and had its like for like brother jetted on the OIF lightning of my friends, I would like to loan it to you to try on your 750 if your interested. Carburation may require tweeking to suit the 750 application.

let me know what you think?
Posted By: JER.Hill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 08/09/16 3:17 pm

Hi Allan, you've pressed my button.

I'm afraid your comment on my 5 speed cluster requires clarification.
a) Yes I do use a splined mainshaft, although what you didn't mention was that in the kit you also have supplied an adapter which replaces the original and allows you to use the original BSA clutch centre.
b) The use of the splined shaft allows you to torque up the adapter to 35 ft lbs, which removed a number of the tapered shaft historical issues. In your mail about you using 100ft lbs torque, from memory the BSA book used to say 65ft lbs, that's just a bit little more "than one for my granny"!
c) When I talked to Mark at PES two years ago about doing the 5 speed, we also agreed a decent clutch was a requirement with the agreement that he would be doing the clutch manufacture.

While I've been reading the post and tried not to comment. If you wish to carry on and have 4 speed CR ratios made thats fine by me. The original ratios, as have been pointed out by Nick L and a few other's to have been less than ideal for circuit racing, even if you go LSR "straight line racing" your ratio requirements will more or less remain the same. I'm not going to talk up my own 5 speed cluster. But you really need to think about getting off the line and ensuring your in the power band after every change.

Another bit of clarification with regards rules, there is a lad in the UK running one of my alloy barrels and a 5 speed cluster in the classic unlimited class of circuit racing and beating triples etc. Bye the way that's nothing to do with me, it the man on the machine.


Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 08/10/16 10:18 am

Thanks for the offer of the head Allan, I will decline though, it gets spendy and risky posting heads around, I am currently fettling the head previously fitted. its had the seats re cut, new guides , bigger inlet valves so its pretty fresh.
You are correct , the 5 speed has a splined shaft, do newby clutches have different centre options?

I have silicone molding rubber, and surf board repair epoxy with glass ball filler, ( I do a bit of board repair , my son can break an anvil with a rubber mallet).
The plan is to fill the port floors as per Mark Parker to end up with a 22 mm port height at the valve guide. currently its 28 mm. A 6 mm gauge will sit on the port floor to let me know I have the correct amount.
Just finished de pocketing the valves , still to polish the scratches out from the burr.

Waiting for clutch parts to arrive,
@Ger, thanks for the link, your man did have the end plate, but no spider, found an ebay supplier who had both , i will get one more rebuild out of this clutch , hopefully by then a better alternative will be available. i may try repairing the worn spider with weld and grinding back to size, these are 60 each!
Posted By: Allan Gill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 08/10/16 12:11 pm

22mm height is what i settled for with the port floor, it works well. (Again as per Marks example) On the Mk1 head it has some filling around the guide on one side, the idea was to direct fuel towards the plug (and because the piston crowns are slanted towards the plug) it works well but gives it an RPM cap of 7200, that said. Thinking on... I have found advancing the igntion also caps the RPM, regardless of the head. Although advancing helped with the midrange.

Regarding the main shaft, i will have to refer to Johns comment above, as I didnt know it came with an adaptor. The adaptor can be used with the newby clutch if it allows the standard clutch to assemble as normal (it will exchange like for like). If they have a different centre option though i do not know. You would have to know what clutch the spline was based on, (ie suzuki etc) then let bob know. This is something you would need to discuss directly with John and Bob Newby, I cant begin to make any assumption here.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 08/19/16 9:26 pm

Some progress.
|new clutch hub. cups and springs fitted, primary drive assembled with 0.025" of shims at the motor sprocket to get chian alignment.
[Linked Image]

I also pruned some material from the clutch adjuster nut , taking it down a size from 9/16" AF to 1/2". There is precious little clearance between this and the inspection cap when the clutch is withdrawn, the old cap had witness marks from their acquaintance.

Rigged up a timing disc with cam timing marks and made a sturdy pointer from 2 nuts , the points wire clip and a long screw.
[Linked Image]
Barrels and pistons ready to fit.
[Linked Image][Linked Image]

[Linked Image]
When torquing up the barrel studs , crack, this one failed, it had corrosion over about 75 % of the crack face so this was waiting to happen, may change all studs as a precaution, .
Getting the broken stub out will be a challenge.
Its below flush but may be weldable, thinking a 1/4 ID washer welded to the stub with a blob, then a nut on top. probably means taking the motor out again , and now its heavy with the clutch and tranny and crank. oh well...[Linked Image][Linked Image]

To cap it all the broken top part fell into the case as the barrels were lifted, , sitting on the sump plate i hope, fishing with a magnet doesnt get it. double scunner.

Inlet port with filler.
[Linked Image]
[Linked Image]

A quality "Ding Dong " hacksaw for 50p at Edzell boot sale.
[Linked Image]

The handlebars are now correctly mounted thanks to info from Stuart, top to bottom, P clamp, cupped washer, bush/ rubber , steel cup, yoke bush, lower cupped washer and Nyloc nut. Now I see why the P bolt is so long, for years I had one of the cupped washers missing , dont believe the parts diagrams!The 71 A65 is missing these parts.
, This needs the cold light of day..
Posted By: Allan Gill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 08/20/16 4:13 am

Nice work on the port, you shouldn't have effected carburation too much, one carburation change I did find which was interesting was at the lower throttle positions like the slide cutaway and idle
Mixture effective area you sometimes need to go one stage richer. From needle jet you need to lean it out and main jet stays about the same, sometimes needs to go richer, but at the same time it will rev higher too. A similar effect from when I first fitted velocity stacks, only with those I went richer at the main jet and leaner everywhere else.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 08/20/16 10:55 pm

Got it out.Masked the area with a bin liner and broad tape,Used a diamond burr about 2.5 mm diam in the dremel to create a central dip,drilled a 3/16 centre hole. heated it , knocked in a torx bit and wound it out, Ding Dong!
Ah , the cold light of day.
Found a spare stud, cleaned it up, loctited it in and spent another 3 hours cleaning and reassembling the pistons and barrels,

Fitting the pins to the pistons was not as easy as before , one needed a bit of warming to get a push fit and the fresh small ends were not as easy to enter as the worn old ones.All back together and cam timed with a Mercer sticky ersed clock, 0.0001" increments for gauging cam lift at 15 thou, stock cam wheel marks were close enough , inlets open to a degree of stock 51 BTDC but close about 6 early, exhaust were much closer all round. I recall these readings from the last build, the feeling of regret at not having that last gob of spitfire in the cam duration. Must look at the lobe centres.
I have a page or two of readings, a tooth either way would put it further out so I will maybe go with this , the other key way options may go unused, plus its a pain getting the cam wheel on and off.
I have ordered spare studs, and some other bits, but I couldnt wait.

With the cam timed I can box up the timing side, thats next.
Posted By: Allan Gill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 08/21/16 3:31 am

Did you have the cam followers refaced?
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 08/21/16 6:21 am

No. Cam followers are still fair, they were refaced years ago when I replaced the cam.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 08/23/16 7:16 pm

Pics of the latest capers.
Broken stud dremel and torx bit.
[Linked Image]

The broken part was lying on the sump plate filter, took off the plate and there it was, no amount of magnet fishing would get it, too many big steel lumps in the way.

[Linked Image]
A better pic of the Ding Dong, my most stylish hacksaw
[Linked Image]

Cam timing set up.
[Linked Image]

Valve timing figures, best of 3 for each one,
[Linked Image]

Figures are generally retarded ( my mistake, they were advanced)a few degrees on opening and advanced about the same for closing.
The clock,
[Linked Image]
I found this in a Mirlees 5 MW diesel crankcase , when it was opened up for overhaul in 1981., it had been in a running engine for a year!.
My father cleaned it up and it works still.

mag base was in the same sump.
[Linked Image]

Got the ports worked down to 22mm height (ish), looks ok needs more width though.
[Linked Image]

[Linked Image]

Did a little more filling, had to replace the drill cord, exciting sparks". using a long carbide burr to hog out filler and widen ports a tad.

Found out that my oil pump drive worm gear has been absent the thrust washer which cushions it from the crank pinion, waiting for same.
Also spent an afternoon saving a good iron oil pump from the delapidated shed,also found the stellite faced exhaust rockers, these need adjusters ( push rod end) 5/16 UNF, a land rover type fits in but the ball is too large for the push rod cub. Need a cunning plan .

Thats a diversion though.
Chatted to Geoff at SRM, re valve springs, new ones dont match book dims, outer shorter, inner longer, turns out they are Triumph spec but work OK in A65s.

Getting close, porting nearly done,oil pump testing soon.

Posted By: old mule

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 08/24/16 6:22 pm

I like those Eclipse tools, I have punches and various rules and small hand tools made by them, a protractor, for one.
Too much to expect that they survived the Chinese invasion, I suppose.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 08/24/16 9:01 pm

Eclipse, = good gear, up there with the best

the senior moment, boxed up the barrels after breaking the stud, then could not remember removing the con rod protectors, couldnae find them in the shop.
Lifted the barrels and there they were. Luckily the Welseal hadnt set up, i am now a huge fan, it not only smells good with a ketone blast but it remains usable till cured, woooo hoooo. Will the barrel joint leak, anti buchinach.(Sp), struggling here , the local expression for evil eye, is loosely translated and pronounced , nearly butcher knife, best I can do .google came up with Balor, bollocks!

in context , its like the green eye or wooden curse , to put he butchenach on something , curses it to fail. like not touching wood. maybe. ive seen machines killed by it.

Replaced the oil pump worm,new washer torqued up. timing side done . Torqued crank pinion worm and nut to 30lbft, kick start ratchet pinion nut to 60 lb ft, cam pinion nut to Qt and locked all off, timing chest needs a new oil seal then good to go.
(should do a wee bit about the oil pump, the spare is asking for it.
Dodged another bullet, when I removed the oil pump worm the old piece shed a flake off a tooth start, ouch, better out than in.The new worm fitted on easy , the old one was distorted and was easy /tight when fitting.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 08/27/16 5:11 am

Big steps forward.
Front forks, completed, the LHS damper adjuster has been drilled and pinned at the coupling.

Timing side finished.
New crank worm, thrust washer , locknut and oil seals, ready to box up.
[Linked Image]

Installing kickstart spring, Jubilee clip over the kickstart shaft to hold the spring tab washer in place, not my idea, but it makes this job a whole lot easier, , a piece of bodgers wire is used to pull the spring into position, one time , no swearing or blood loss.
[Linked Image]
In position.
[Linked Image]

The clutch is working , the cable got some TLC with a new rubber boot and a piece of heat shrink over the frayed outer. Spring nipped up to just past flush, end play set at one whole turn out.
Feels good.

Primary side boxed up as well and all gaskets trimmed with a scalpel.
On with the head coming soon.

The last bit of the rewire, new Boyer tails.
[Linked Image]

Quite pleased with the clutch indicator, old compasses .
[Linked Image]

Last bit of the jigsaw, the centre stand is done, Mackenzies are living up to the Just In Time system, nice job, it weighs a lot ! now straight and one inch shorter.
[Linked Image]
Thanks to Chris who did the job within 24 hours ( when he was told about it, no previous info had got through, got to speak to the organ grinder , not the monkey).

Summer is running out!
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 08/29/16 8:13 am

Porting,Mark has figures of 110 CFM for the stock port and 134 CFM for his filled and modded ports which I am trying to copy. I now have a round 30 mm port which transitions into a D shape with 22 mm height just behind the guide and 35 mm wide at the same point.

As a side note , Mark Parker used HD XR 750 ports as his models for the D shapes and bowl deepening, in turn HD copied / borrowed from the 350 Goldstar head design which was very good, the 350 being a very effective motor with 32HP in race tune, more BHP/litre than the 500 at 42 HP. Its a pity BSA hadnt copied this onto the unit twin heads.

Reading more about BSA head tuning on HP Stans B50 page, he mentions the head tuner Dave Aldana used, he factory supplied him with a number of heads , HP was found by deepening the upper wall of the bowl to the point the upper surface was acting as a diverter to shoot gas across the valve face and increase flow at the other side.Having watched a few Dave Aldana vids from the past , this certainly seems effective.
I bore all this in mind when weilding the burr.

Getting to 35 mm took a while, this also involved deepening the bowl by raising the roof round the guide. I havent broken through anywhere, Mark recommends leaving the area immediately upstream of the valve guide untouched as this is the thinnest point, I have gone about 2 mm into the roof either side of this. Filling was easy, removing took a few hours, I taped an old head gasket to the head face to prevent collateral damage, with the guides in place some spots are awkward but they do prevent the burr from accessing the thin point ,so, every cloud etc.
The worst part of this was my hands getting tired from wrestling the drill and the constant danger of trashing the seats inadvertently.Whew, glad thats over, valves fitted temporarily to finish CC clean up and check port volumes.
This is one time where an air tool would have been handy, my drill only spins to 2K rpms, the burr is meant to spin about 20 K, ,however a moments inattention with the windy tool can be a lot more catastrophic!
Posted By: Mark Parker

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 08/29/16 10:12 am

You need one of these Gavin.

[Linked Image]

This thing is fairly big, with I think 6mm shank, not dremmel size, I use it in a cheap air type die grinder.

And it's much easier with the guide out. If you make a paper cut out of the profile you should be able to get it pretty close. I use that cutter working either side of the guide hole. I also use a sawn off 6mm bolt shank slotted on the end (with a hacksaw) to hold a piece of sand/emery paper and use finer grades to get smoothness. Put the paper in so it's out past the end of the piece of bolt. If you work from the combustion chamber side tape the back of the paper down or it will be sanding the valve seat.

I hope it works for you. It will be interesting to see how it goes. Taking a cast of the port is worth doing to see what shape it actually is.
Posted By: Mark Parker

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 08/29/16 10:15 am

If you take a cast, spraying silicon spray into the port helps it release.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 08/30/16 7:23 am

I have skipped casting the ports, I reckon the valve guide will make it impossible to retreive the mold.

Pics of porting,
[Linked Image][Linked Image]

Checked port volumes, TS 71mL, DS 70 ml.
checked the taper height in the DZ and found the floor was a little overfilled, equallized the heightDS to TS, retook volume and got 71.

Cleaned it all up and installed the valves, new springs and alloy top collars.
[Linked Image]

Annealed the head gasket.
[Linked Image]

Head on, used copper coat gasket sealer, fitted O rings to drains , cleaned all fasteners and torqued up to 30 lb ft, even remembered to install the rear headbolts before offering the head to the motor.
[Linked Image]
[Linked Image]
[Linked Image]

Transmission, check,
clutch, check
lubrication, check, filled feed side from a temp funnel, pump primed both sides and returning OK.
5 gears, check.
Wiring , check.
Cam timing, check, ignition timing, check.
Just carbs, pipes ,push rods and rockers to go.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 08/30/16 6:06 pm

Checked rotation, new big inlet valves are meeting the pistons in a confrontational style.

Retarded cam timing, still get a little clash, pistons coming back out for machining inlet cut outs.
It must have been close before with the stock valve sizes, its definitely too close now.i reckon about 2 mm should do it, had a quick chat on the competition forum about this, blown income reckons on 0.050" min as a safe clearance.

Thats what you get with change, " there is no change without violence " according to chairman Mao.
Theres a chap called Blod in Benderloch who is motorcycle savvy and handy with a mill, he is getting a call in the morning.

The hit point is at the lower section of the valve cut out, not the rim of the cut out, I wonder how thick these pistons are at this point?
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 08/31/16 3:43 pm

Head going back to SRM to have the valve pockets deepened, they are not to spec.
Tip to valve spring pocket is 1.694" TS and 1.680 DS, should be 1.730" - 1.750".
The GPM pistons fitted had been run in a 750 big valve previously ,same cams and followers, so its not them.
During the postal intermission I shall press on with the centre stand and front wheel, this will allow some first stage fork tuning. Theres been no radical changes here so , touch wood, that should be pretty straightforward.
[Linked Image]
Posted By: Allan Gill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/01/16 3:15 am

You might have been better just laying strips of plasticine Gavin as opposed to one large part, it would have made it easier to see clearance.

Looking forward to seeing it all come together
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/01/16 7:04 am

That was attempt number one, less clay subsequently, it does give a good overall impression though.

Posted the head back , next day delivery insured to the max, 27.60 ouch!
Got on with a few wee jobs, carbs refreshed, old banjo filters were 0.047" at the seal, new ones 0.050". Alloy float needles and new needle clips.The new throttle rubber has disappeared!
Reviewing the whole job, I am seldom right first time, all changes have a ripple effect adding a faff around factor that is always more time than you would think.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/02/16 6:02 am

John has 1 mm head gaskets as an option, each mm gives 6.05 cc more or less CC volume, currently its around 9.something to one with the 2mm currently fitted so a 1mm gasket would bring it up to around 10:1 , maybe pushing it with the fuel available, although Marks motor seems to manage considerably more. Given that the current set up seals very well and I am using stock con rods I may err on the safe side, but who knows, my reluctance to lift the barrels (again) and refit the pistons might swing it.
After searching everywhere for the throttle grip it showed up on the bench! next the quest for cam timing, about to explore the other key way options on the cam wheel to get as close to book numbers on the retarded side as I can. Also scrounged up a chain link with x ring seals, will rob this for the oil manifold seals , other folks have posted about these here, supposed to give a more oil tight joint.

The new Amal rebuild kits are good, apart from the usual gaskets/ seals , filter they come with new improved pilot air screws, these are noticeably more refined than the old ones, better machining and a subtly different taper.
Posted By: JER.Hill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/02/16 2:21 pm


I've used three base gaskets in the passed. But some people just want to rebuild the engine in the simple manner, bought one gasket set and are only going to use it as a road bike. so the 2mm head gasket gives them the option. As you said for the ideal squish etc a 1mm head gasket is the best way to go. In that they get a one build motor which will give good performance, not quite out of the box so to speak, however with a straight forward build and a motor that should run with out pinking.

In Gavins case he's taking Mark's porting, and using the big bore with the 5-speed cluster, so I'm with you that a 1mm head gasket would be the better option now, as opposed to his original intention.

Guess thats the trouble when you start chasing the dragon (did't mean that in any way to what might be inferred).

Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/03/16 8:21 am

When I first got the bike Devimead used to offer two gasket thicknesses, I tried the thin one ( less than a mm) and struggled to keep the head sealed, there always seemed to be oil getting out somewhere. Even lapped the head to the barrels to try and cure this. I reckon the alloy barrels help here with less differential movement.
I agree about the thinner gasket option giving a better CC shape, OK go on youve talked me into it, the 2mm one has worked well with the undersize tapped holes , same thing with a 1mm would be OK, I have a few base gaskets lying around, at least one of the thicker black ones somewhere, and a dodgy looking pink one thats never been used.
\Been researching wasted head bolts, taking shank down to thread min diam means the whole bolt is stretching rather than the threaded section, good for alloy barrels as the clamping force does not get so high as the alloy head grows, less prone to tearing out threads ,I found most interesting info/graphs on a vee dub site which I can no longer find.

While the heads away the fasteners may go on a spinning diet, should I , shouldnt I?
Posted By: kommando

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/03/16 8:53 am

It is not recommended to waist the bolts on a lathe by ARP, not sure why. They mill them instead which would take an age on a mill and need a rotary table, a good alternative I have seen is to mill the unthreaded section on 3 sides to form a triangular shaft.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/04/16 12:37 pm

Here is the cam pinion , key ways are no.1 with the etched arrow, number 2 with the red dot, and number 3 unmarked.
[Linked Image]

Number 1 advances the cam timing about 5 degrees, number 2 is dead on , number 3 retards about 6 degrees. i am now using number 2, it was previously in number 1.
[Linked Image]
The red enamel marks should help save confusion in future.

Fitted the chain x rings to the oil manifold , they are about 20 thou larger OD than the O rings but it seems to nip up OK, time will tell if they are any good. Edit, retrospective, they leaked right away, on inspection one was distorted, now oil tight with normal O rings.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/06/16 7:06 am

[Linked Image]
Correct handlebar mounts assembled.

Front brake cable shroud from a box of stuff, MZ origins.
[Linked Image]
Motor reassembled, timed up , head surfaces cleaned , gasket annealed, waiting patiently.

Running out of jobs, shock off for a tart up, the shortened stand is great , works very well, easy to deploy.
[Linked Image]

Pre-stretching the centre stand spring.
[Linked Image]

Caught the blow lamps having a stand off, the one on the left is a new find, a 200 K, with integral soldering iron stand, needs a new piston seal, the one on the right is more nimble, I think it will win.
[Linked Image]
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/06/16 3:36 pm

With the bike on its own two wheels I was able to get some fork base lines established.
Using the top of the top nut to the fork drain screw i measured the following.

Max extension on stand , 755 mm.

off stand , rider on , brake on sink down and relax, 715 mm.

lift up and relax 725mm

725-715 = 10 mm stiction. 10/2=5 mm

Max extension 755 - ( 725+5=730 for midpoint no stiction) = 755- 730 = 25 mm static sag.

these figures are without cylinder head and fuel tank and oil,but I added the babbit ingot to compensate, wont be too far off.

Rechecked after slackening front mudguard mounts, fork end clamps , pinch bolts,
nipped up from bottom to top , similar readings.
Sag should be around 25% of total travel, total in this case is 6", or 152.4 mm, 152.4 / 4= 38.4 mm. The pre-load adjuster are wound in flush with the top nut , will back these off a bit and re try.

Froma web site on suspension tuning
"Street bikes run between 25 and 33 percent of their total travel, which equates to 30 to 35mm. Roadrace bikes usually run between 25 and 30mm. "

So I am in the ball park, which means no fork shortening by adjusting spacers , not without softer springs. That can wait.

Bouncing it around the damping seems effective, not a fair test though.

Stripped the back shocks to clean them up, one was suspiciously oily inside, but seems to damp OK. These Hagons are very old and due for replacement soon, even sooner now that I have found this. The non oily damper would stay in when compressed , the oily one self extends slowly after compression?

Had a nasty moment today, called SRM to see if they had received the head, not, according to the desk wallah.

Panicked, cant find the postal chitty with the tracking number.
Down to the PO, they give me some forms , no record of tracking number on file.

Another call to SRm, this time it turns out warranty work goes a different way, my head is in the shop, a quick chat with Geoff and I am placated. whew, PO calls up seconds later to say they found the tracking details in the "special " drawer, all is well, hurray.

A few other jobs to do, check wheel alignment, top up all lube levels, polish wheels.

I want to smell combustion ,fed up smelling of paraffin and meths.

Posted By: Allan Gill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/06/16 3:49 pm

If you haven't already Gavin, order a pair of 105 needle jets and to be on the safe side a pair of Norton needles. Your going to find a rich mixture and slow until you get it tuned in.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/06/16 4:33 pm

thanks Allan.
i have 105s on the shelf , somewhere, will get Norton needles, wWhats special about them?
Also have no.3 slides and jets 190 -230 in stock.
Current set up.
MJs 200, NJs 106, slides 3.5, needle stock,no.1 top groove, pilot screws 1 turn and 1.25 turns.
This set up ran well, clean pick up, no surging, about 1 mile with choke to warm up., good mileage.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/06/16 7:27 pm

Back to the forks, took off the bars to adjust pre load, checked LHS damper adjuster, no function, just spinning, took the top nut off, the coupling for the damper adjsuter had unscrewed from the top alloy central screw, put it all back together with more engagement in the coupling ( soft ally threads on the male part), backed off the preload to two rings showing, about 2mm.
New figures give 43 mm or 28% for sag, that will do, plus the pre load adjusters are clear of the handlebars. Of course once the bike is complete and I have my kit on this may change, the ingot weighs about 20 lbs ( guessing) so its probably not enough.
Stiction is variable without an assistant to steady the bike the figures range from 7.5 mm to 20 mm.
I am sure that will settle down once the new bits settle in a little.
Forks, done for now, back wheel and chains next.
Posted By: Allan Gill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/07/16 2:22 am

The Norton needles you will be able to get from Amal, the only pair I have are on my lightning. They are fatter than Normal it will help to lean the mixture out further.

[Linked Image]

Main jets will be a funny one. The first head I worked on, I also sculptured the top top the port around the guide, I had to drop 4 main jet sizes but also lost some top end rpm's, all subsequent heads don't get touched in this area and rev higher and require about 3-4 main jets larger. As your pulling 750cc I couldn't advise either way but I'm guessing you will have to go leaner, as your vacuum signal on the carb will be stronger.

I'd start with the 105 jet and needle in the middle groove for starting with. Strangely enough whilst going lean thoughout most of the range, I've sometimes found I've needed a richer slide, your number 3 should be enough.

If you don't have chokes fitted, I find its a good time to have them fitted. If you've gone too lean you can close them down without melting anything.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/07/16 5:14 am

looked into the Norton commando "4 identifying ring " needles, they were 0.25" longer? and originally paired with a cutaway orifice spray tube, do you fit this as well?. Will see how this goes as is and tweak as needs be.
I have chokes fitted, over the years with more understanding and fuel changing I have ended up with leaner all over from stock 650 settings, 220 MJs now 200s, no.3 slides , now 3.5s, needle no.1 clip, previously middle. the only area that seems to be richer is the pilot air screw settings, 1-1.25 Turns Out.
According to a Norton site i checked out 105 NJs are very different beasts from 106s, could get interesting.

not many jobs left, the oil spine sump plate hasnt been off for about 20 years, better look in there for completeness sake! i hate doing this job ,theres nothing pleasant about it. I may find something interesting in there.
Posted By: Allan Gill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/07/16 6:46 am

yes it is longer as well, I would start with the standard needle and then switch if you find the plugs are fouling at cranking speed, or if you start dropping out on cylinders, but if your using the standard cam you might not need to get this lean.

I use the norton needle with the standard spray tube, I asked Amal about this and was told to refer to John H as per the differences. I still dont know!

One thing I did find aswell was I could get away with more ignition advance with the smaller ports. once your setup it would be worth while advancing a couple of degrees at a time and looking for improvement. With stock setup I was retarding the igntion to get better performance.

Apart from the size the 105 four stroke needle jet is no different to that of the normal 106

I ended up with having to fit 932's to get the mixture leaner, and so the jetting process starts again. I was surprised to find quite a power hop when going up 2mm on the choke size, using the same lean jetting as I ran in my 930's I am now starting to richen it up again.

(928's worked well at bottom end, but with big cam and small ports it was impossible to jet properly, and ran pretty rich)
Posted By: kommando

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/07/16 6:49 am

I have the Norton needle with cutaway spray tube on a ported and MX camed B44, works well but never fitted a std setup to know if its better or worse.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/08/16 12:13 am

, "I would start with the standard needle and then switch if you find the plugs are fouling at cranking speed, or if you start dropping out on cylinders, but if your using the standard cam you might not need to get this lean."

How do the needles affect "cranking speed"?
Posted By: Allan Gill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/08/16 1:57 am

I know what your thinking. I can't explain why either.

When I switched from my 473 cam to my x12 cam I couldn't get the bugger to start the plugs were just covered in wet fuel, I ended up fitting the Norton needles and it did start and ran cleanly. If nothing else it got me in a position where I could run the bike and start working on the jetting throughout.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/09/16 6:39 pm

Wheels aligned using a builders laser, light string,.
last job before the head comes back the oil spine filter.
Not seen the light of day since 2,000 , a few sparkles in the mesh and 40 year old red hermatite,
this eventually let go after soaking in meths and brushing.

[Linked Image]
[Linked Image][Linked Image]
I am not in the habit of disturbing this filter, this may be the last time now the spin on filter is BIS.

off for a "swell " time in Tiree, its hurricane season, surfs up, testing plastic to destruction for the next week..
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/15/16 6:21 am

Holed up in surf shack on the Isle of tiree.Plastic holding up well, stainless to alloy failed, testing conditions wind 25-30 knots, logo high surf.UJ pin let go, on the inside luckily.Traigh Thorasdail(the Mazes) claims another victory over a dancing monkey.kiters no longer in the ascendant, windsurfers still in majority, the newness must have worn off.

Back to the bike, it seems SRM do not acknowledge/ reply to e mails, have been trying to find out when the head will return, not the first time i have found this , will telephone today for an update.

Called, paid postage, head and pushrods go in post, kickstart lever to follow after plating. They do get e mails, just not great at responding.
Posted By: Allan Gill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/15/16 7:45 am

what was wrong with your pushrods?
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/15/16 8:15 am

Wrong length, stock, should be A50 length for big bore, shorter of the minor advantages of the big bore, piston crown to gudgeon pin is less, hence shorter barrels and pushrods.Shorter = stiffer.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/23/16 8:42 pm

A wee update, back from the Hebrides ( suitably thrashed, got Crossapol in cross off , 15 knots and 4 foot surf all to myself on the last day, lovely, milked one wave to the end of the beach then the wind dropped and took the walk of shame, got so dehydrated I ended up drinking the water from one of the many flotsam bottles on the strand line, it tasted great!)
The head is back from SRM, inlets sitting back into the head a bit further, correct pushrods too. I got a replacement kickstart lever LC style, beautiful piece ,but, it doesnt fit a 71 spindle, the cotter cut away is a different height on the 71, old lever going back on as a temp solution, it has already been weld repaired, years ago and there are signs of cracking near the welds.
Just had a couple of teeth out so not to lively at the mo.
Currently checking head fastener lengths, barrel threads with a view to a thinner head gasket.
Clearance checks tomorrow.
Posted By: Allan Gill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/24/16 2:46 am

As you may already know Gavin the OIF quadrant is longer than the pre OIF type. I am not sure the real reason why the OIF should be any different though. However, the 3 ball ramp clutch cover is "thicker" for want of the better word than the earlier type and I found that the lever would bind on return with the normal quadrant for my model year when I had the later cover fitted with the early quadrant.

I fitted the later quadrant and ground (hacked would be a better word) enough off so that the early lever would fit with the cotter pin

What doesn't make sense though is... The early quadrant was fitted to the 70 models with no problem and they had the ball ramp clutch. So is the OIF outer cover different or did they grind the kick start
Lever back a bit on the 70 models. I don't know but that's what I found.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/24/16 7:07 am

There is one extra screw in the outer cover of the 71,everything about the 71 cases suggests strength compared to earlier cases. The kick start lever is the the same as 71 Triumph twins as far as I can see, this should make sourcing a new one a lot easier. Probably trying to simplify the spares stocks.I have a few 1970 parts lying around , other bits of the gear selector, the "grannies tooth " that engages in the return spring is much chunkier on the 71 compared to the 70.
I reckon that if the company hadnt gone bust the A65 would have seen a few more interesting developments, on paper it is way ahead of both the Triumph ( no push rod tubes ) and the Norton ( solid unit construction , with the camshaft where it gets crank splash) before it finally expired. There are extra unused bosses cast into the rocker cover suggesting more was to come, the timing chest looks like it was meant to take an end feed oil seal, just beaten by the bean counters, the draughtsmen had it planned, the foundries had it cast, shame.
Posted By: Adam M.

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/24/16 8:44 am

Wonder if you have a picture of your inner timing cover to show it ?
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/24/16 8:22 pm

Theres not much to see Adam, coaxial with the crank the in side of the timing chest has a round recess which is cast in, this is what gets machined out to take the end feed oil seal, the Devimead mod was to add / weld an oil gallery to mate up with this. Les Mason who formed Devimead originally worked in the BSA comp shop, maybe he would know, it could just be that this recess was needed to clear the worm gear locknut but to me it looks like a bit of forward planning. A very minor adjustment to the pattern to add the oil gallery would have been all that was needed to complete this.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/25/16 6:47 pm

Got on with it a bit today.

Head and tools.
[Linked Image]

The white tape marks 12 " tape to wrench centre, setting the ratchet 1 click towards acute from 90 degrees makes the tape to spanner head 12".

This is flawed logic see the following helpful post by TR6 Ray.
[Linked Image]
[Linked Image]
Its not cock on, but its pretty close, better than using 90.

[Linked Image]
[Linked Image]

Sketch of head clearance to piston rim, valve cleearance, rocker arm pad removal.
[Linked Image]

The valve sits a good bit deeper, so much so that I have ground 0.070" off the RHS rocker to get the push rod to fit, there wwere generous blobs of stellite there so useful weight loss, ground through quite a nasty void on the way, it cleaned out. The pad ends were pretty cobby anyway so Ive removed a bit from the sides that was just along for the ride.
[Linked Image]

Ground DS rocker on left. will polish these faces when certain of set up, I may take a bit more off, it fits just with the adjuster backed right up, so there is scope for a bit more if needed.
[Linked Image].

Took two hours using a dremel , 10 mm orange stone for bulk, then 8 mm orange stone to correct the radius, used blue to check level, only about 15 iterations.
Timing side still to do.

The valve was only fitted with the outer to test, definetely spins now, hurray, loads of clearance, o.125 at valve, 0.060 at OD of dome tightest.

Will probably stick with this. maybe, maybe not , loosing a further 1mm 0.040 " ish with a thinner head gasket will bring this down to 0.020 min clearance/ squish, is that enough, opinions welcome? Means more rocker pad grinding if I do go for more comp.

Still to check valve geometry at mid lift, I had shortened the previously fitted Alloy / steel capped rods to make this work before, the inlet pads were OTT any way, when I ground them down to the point they would fit with the push rod in place and allow me to pass the spindle through the blue showed rpad to stem tip on the edge of the tip, the radius was corrected to move this towards the centre a bit, I want to stay 0.020 min away from the tip OD, doesnt have to be dead centre since it slides forward in motion. Footery work..

Got a good tool chest from Aldis a month ago, , BSA stuff in top drawer, it ate everything else, now have 3 empty boxes and box of also rans that never get used. bench top now a bit clearer.
Posted By: TR6Ray

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/25/16 7:20 pm

Nope -- this is wrong:

Originally Posted by gavin eisler
The white tape marks 12 " tape to wrench centre, setting the ratchet 1 click towards acute from 90 degrees makes the tape to spanner head 12".
[Linked Image]
[Linked Image]
Its not cock on, but its pretty close, better than using 90.

[Linked Image]
[Linked Image]


Sorry Gavin, but you are wrong about that. What you are doing will give you the incorrect torque.

Torque is the product of the applied force (the push or pull delivered by you to the handle of the wrench), multiplied times the length of the moment arm. The moment arm is the perpendicular distance between the line of force and the center of rotation. If you had the extension at 90 to the body of the wrench, and your arm also at 90 to the body of the wrench, the perpendicular distance from the extended centerline of your arm to the center of rotation (the head bolt) will be the same distance as if you were not using the extension at all.

You don't have to take my word for it, look at the diagram I copied for you from the Snap-On website. The second figure is the one that applies if you don't want to do mathematical calculations to figure out the modified setting for your wrench:

[Linked Image]
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/26/16 5:11 am

Thanks for that Ray, luckily I didnt go to full figures, stopped at 20lbft, was messing around prior to head fitting, nice explanation.
Will leave my mistake in for others education.
Posted By: TR6Ray

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/26/16 7:58 am

You are welcome, gavin. Actually, in the scenario above, you would have shortened the moment arm very slightly by the position of the adapter. That would have resulted in a very slightly reduced torque. If you were going for 20 pound feet, you would have actually gotten

(20 pound feet x cosine15)= 19.3 pound feet

It wouldn't have mattered in the grand scheme of things. I just wanted to save you some unnecessary trouble in setting up your wrench in the future.

The bike is going to be awesome. Can't wait to hear about the on-road results of this latest go-around.

Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/26/16 5:47 pm

Cheers Ray, its getting close, John has a new thinner gasket, so until i get these i am refining a few odds and ends. Trimmed the torque wrench adapter to clear more of the rocker box and make life easier.
Got all the valves fitted to the head, will take a full set of clearances at 2 mm gasket once the TS rocker is ground to size, nearly there.

Rockers in progress.Got over enthusiastic with the red enamel.
[Linked Image]
LHS rocker inprogress needs more off the inside of the pad, took the bulk off with the big grinder , much quicker 10 mins.
[Linked Image]

New tool roll along chest contents.

Top drawer BSA stuff
[Linked Image]
1/2 of a halfords pro set
[Linked Image]
Brutal stuff
[Linked Image]

Scrapers and metrology bits
[Linked Image]
Hitting things and the cordless dremel.
[Linked Image]
Other 1/2 of socket set
[Linked Image]
Bottom drawer big stuff and odds and ends.
[Linked Image]
Bike and box
[Linked Image]
MZ 250 fork gaiter , fitted a treat, decent rubber too.
[Linked Image]

Got a wee oil leak somewhere around the OPRV, needs fixing.
[Linked Image]
Same as before but shinier, matching clocks would be good, the grey face speedo needs a rebuild.
[Linked Image]

Other drawers
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/28/16 6:50 pm

More work on the rockers.

Grinding pad.
[Linked Image]

Valve open.
[Linked Image]

Valve closed.
[Linked Image]

Wipe mark on rocker pad.
[Linked Image]

Initial pad contact, no spindle spacers, rocker moved side to side for start point.
[Linked Image]

Full stroke wipe mark.
[Linked Image]

A day later, onto the RHS.
[Linked Image]

1st iteration wipe mark LHS, not very centred.
[Linked Image]

The magnet on a stick saves the spindle spacer falling when the spindle is withdrawn.
[Linked Image]

Rocker pad side view, profile now very different from start condition, almost finished. Note gap between arm and valve spring retainer, a bare mm.
[Linked Image]

Wipe mark more centred, it took hours of slowly slowly catchee monkey to get this corrected.
[Linked Image]

Final clearance checks,
[Linked Image]
A light touch near the valve pocket rim, plenty of room.
[Linked Image]

The closest point round the piston Dome OD.
[Linked Image]
[Linked Image]

Final head assembly next week, off to look at a potential lathe Myford ML7, meet up with John for moral support and lathe inspection.

Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/28/16 7:15 pm

i did a quick internet trawl about rocker to valve contact, as long as the strike is at least 0.020" from the valve centre all is good, my crude grinding technique is very time consuming, keeping the pad flat in the same plane as the spindle is not easy!, the blue tells me which side is high/ low. Open to advice /criticism here, in an ideal world the rocker pad radius should be the radius of the spindle centre to valve tip, some sort of jig to maintain this would be a good thing.
I have limited facilities and keep reminding myself that the other side which is stock has a point contact that varies with the the thackery washers, so is absolute dead centre a must have or is perfect the enemy of "good enough"?. I tick the 0.020 " min from valve tip edge box , and the wipe is as short as I can get it. One other niggle is that the weld I am grinding away at is hard enough, when grinding it produces no sparks, it is F hard and has eaten away the orange stone , unlike the rocker arm material which produces small yellow sparks, not being familiar with stellite I am not sure if I have gone through the previous hard layer or if it was all stellite, what say you. If I have gone through it , these labour intensive items will have a short life span!.
i have spare stock rockers if it all goes wrong.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/28/16 8:49 pm

Its too late for go easy , if there was stellite it went about 70 thou ago, what are the options, go further in and rebuild with stellite, case harden/ I have some old toe nail clippings and a source of heat?
Posted By: Mark Parker

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/29/16 3:54 am

I used to have hardfacing metal sprayed onto cut down valves, that worked alright. Though I now just fit lash caps. It may be worth trying the std rockers to see how they fit? I use mushroom adjusters which are good, but either way the geometry needs to be good, with the adjuster wound down a bit. A mushroom head needs a little room.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/29/16 9:50 am

Thanks gents,
"They may just have been built up with hard weld not stellite, the guy who used to do my race cams built them up with what he called 'cold weld' and ground them back down to the form, that way i didn't have to pay for a 'blank' every time."

I think this is what I have been grinding through. It is weirdly sparkless when grinding, looks a bit like the "dissimilar" SS type welds that allow ferrous to SS welding.
On the plus side I have shed a few grammes from the important end area and the pad surfaces no longer have pits .
They are staying in for now, time will tell if they wear or not, if they do, I will grind more and have them faced. I reckon they will be fine judging by the hardness when grinding.

I have to fight the push rods in even with the adjuster backed full out (( it was like that before anyway), and if I go to the thinner gasket option I still need to lose another 40 thou off the pads, getting close to the valve spring top keeper.
Must get real numbers for this, By eye, its still over a mm and as the angles change and with it being half the distance from the centre of rotation this doesnt close up as much as the pad moves down when grinding.
The thin 1mm gasket option will bring my Piston to head clearance down to around 0.020" at the tightest spot round the dome OD , is that enough?
Will probably build it with the 2 mm gasket for now and try the 1 mm one for a caper next year.

Mark , I considered shortening the valves, there isnt much to play with, how thick approx are the lash caps? How far do they overlap the stem.
The distance from valve tip to valve collet top is 0.173", 4.4 mm.
Losing a mm or so here might help a lot.
The more I ponder this the more shortening the valve makes sense, hmmm, off to look for lash caps.
Posted By: kommando

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/29/16 10:35 am

Look for VW 8mm lash caps = 0.315 dia vs 0.3125 and cheaper due to increased volumes.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/29/16 2:05 pm

Cheers John, useful tip, haha.
More measuring, beginning to enjoy this,I had a couple of teeth out last week and wasnt really top form,using the dremel kept reminding me of the dentist, but now the pain subsides and I can think straight.

Clearance of rocker arm to spring collar, 0.028" with feelers.

Angles look good, mid valve stroke is 90 degrees, close enough for country work anyway, pleased with this.

[Linked Image]

Stuck the rule to the frame with a NIB magnets, the rule is parallel to the v/v axis , referenced off the top collar, it help with the angle visualisation and shows me roughly mid stroke, the clock gauge is too pernickity for this.
[Linked Image]

The camera lense and parallax are messing with this, they were parallel , honest. Mid stroke, 90 ish.
[Linked Image]

Valve closed.
[Linked Image]

[Linked Image]
Valve open.
[Linked Image]

mid stroke better angle.
[Linked Image].

Theres still the matter of valve spring fitted length, but otherwise, lookin good, as my old journeyman used to say, i am "the man that ate the biled ham , raw", quite pleased.
off lathe hunting soon, a potential Myford ML7 is in the offing.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/29/16 3:21 pm

The way it is the angles are pretty good, the measurements are crude but the arm gets to 90 degrees around mid stroke, theres still scope for a little more to come off the pads, enough to ease fitting.

Limiting factor is the 0.028" at the arm to valve collar (these alloy collars are possibly thicker than the steel ones, must check), leaving a safe 0.010" minimum clearance would allow this to come in another 18 thou, which translates to roughly 36 thou at the valve tip.
If the pads wear , valve stretches or seats recede this clearance will close,hmmm. Better leave it alone. Will polish off at this. This pretty much rules out the thinner head gasket, with these rockers anyway, Will dig out some stock inlet rockers for comparison.
Must check installed spring heights.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/29/16 6:47 pm

Thanks again Nick, will leave things the way they are, the spanner tip is a good one, its almost ready to box up. not done with polishing yet, got distracted, I have been scheming and sketching, I have a cunning plan,. A 6mm drill sits neatly between the rocker fins.
Inspired by your oil to the head mod, heres the plan, 2 off 6 mm OD pipes set into the gap between fins 2 and 3 with JB weld on the rocker amplifier, drill from inside cover to Pipe , 2 jets per valve one at tappet, one at guide , diametrically opposite the valve drains. Jet sizes will start small, dont want to flood the head too much. Possibly smaller jets at the inlets, than the exhausts.
The rocker cover will have two 6 mm stubs out the front to pick up a small cooler, fed from the OPRV dump line. To connect into this I will drill into the vertical face, tap for 8 mm and bring out a stub maybe in Cu so I can use a capillary elbow for the 90 , and forward and up to the wee cooler.maybe through another filter, I have a spare base knocking around somewhere. more oil volume is good, with two cannister filters it would gain a useful 3/4 of a pint.
Would be almost invisible ( not if I fit a filter) and pretty reversible, just some wee holes to fill .
Posted By: kevin roberts

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/29/16 8:05 pm

gavin, this is the best thread on this forum.

if you'd clean your fingernails every now and then for the pitchers it would be flawless.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 09/30/16 1:57 am

"if you'd clean your fingernails every now and then for the pitchers it would be flawless.
Thanks for the compliment,my head is swelling to match my jaw.
Ha !, i had noticed as well, nails trimmed.
I should have done the oiling mod when the cases were bare, Doh! I have a spare OPRV, would be easy to mod this and solder up the hole that bleeds off to the dump gallery, drill the dome cap and take the oil line from there. Reversible too. Must get some 6 mm Cu pipe, off lathe hunting with J.Will report back tomorrow.
I see another potential side benefit, adding mass to the rocker amplifier may reduce the rattle.
Posted By: JER.Hill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 10/01/16 2:23 am


I have one of the old style OPRV's laying around, I'll dig it out and you can pick it up next week when your across to pick-up the lathe, might even have a grub screw for you, although I'll need to see what the size is, but I'll have a look at a set of empty cases.

Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 10/01/16 2:40 pm

Cheers for the pics Nick, correct me if Im wrong.
Do they show two OPRVs, the old ball, style and the later piston?
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This looks doable.
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Does this pic show transfer ports so the piston can allow oil to the dome chamber?
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Whats the piece poking out the LHS, I am not familiar with the earlier OPRVS.?
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Ball on seat ?
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Soring on ball?
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Part assembled, spring relaxed?
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View from motor side, ball on seat in port?
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Outer hex, showing spring seat with holes?
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Tapped outer hex?
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Whats the off centre washer hingmy lower RHS?
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The new stud coupling is screwed into a drilled and tapped outer OPRV hex?
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Handsome Bonnie ,
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A wee camera tip , doing this thread has helped me learn a few dodges using a compact Canon G10 , when I take pics like this I set the camera to manual focus, set for 10cms for single items or 20 cms for a more general view, with the strap pulled tight round my neck I can sway back or forward to get a sharper focus. A tripod is better/.
|For closer still I put the bench magnifier over the subject then shoot through that,although the flash angle can cause glare, tilting magnifier around to a sweet spot.;
Pics of bare steel and alloy need the flash settings to be turned down to -1 or -1.5.
I still havent figure out how to turn down the rust amplifier setting, looking at the pics of the rear shocks , I hadnt realised what a state they were in. Looked passable in real life.

The lathe hunt went well. Reached a turning point hoho!
Now the pleased owner of a lightly used Myford ML7 with some useful stuff, stand, 4 and 3 jaw chucks, face plates,drill chuck , 1 set of change wheels, fitted with a clutch, tilting Z axis milling attachment, full set of German Carbide bits, never used, other chunky tool bits various shapes. Travelling steady, angle poise lamp. CP motor 1/3 HP, . With some nice old paper work, installation guide and accessory lists plus other odds and ends.
Noticeably absent, no tail stock centre,no foot mounting blocks to lift it off the suds tray, no coolant pump, wiring a bit incomplete , no E stop or other switches, it has a reversing switch on the stand, no measuring tools. Otherwise very complete, oily with light surface rusting, reasonable paint. The seller knew nothing , the previous owner had been a modeller judging by the price list he did some tooling up in 1983 , doesnt look like its been used for ages. Of course once I had spotted it on Gum tree , severa; other potential buyers surface, but the seller was decent and allowed me first viewing, it was about 150 miles away from home, but in a part of the world that I know quite well and conveniently close to where John lives, he came with for a knowledgeable eye, thanks JH. I was first caller, the early bird got the worm. Its going to need a bit of cleaning and wiring, and a space to use it in. Should be fun getting it up and running.

Posted By: JER.Hill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 10/02/16 3:25 am

Hi Nick

Good informative photo's. I take it your running your OPRV line up to the Tee before the Tee into your return line. The Tee then feed the rocker supply with surplus going to the return, or in the case of the valve being on seat, this hook-up allows the normal return to feed the rocker supply. Looks a good modification to get a bit more oil cooling to the head.

I once did a similar end-feed system and used Airoquipe hose and fitting which kept it neat and tidy.

Sorry to hear your T120 is leaking and toolbox lid took off on its own.

Posted By: Mark Parker

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 10/02/16 3:56 am

Nice looking end feed block, that's a better system than welding. I like that you can check the seal by removing just the outer cover, feed pipe and that block. I could make one of those on the the little lath I bought. I've had seals fail a couple of times and simple replacement is always better than complicated.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 10/02/16 6:49 am

Great info, the wee hole in the rocker spindle centre boss is a much neater idea than my plumbers fantasy, thanks for sharing.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 10/02/16 7:40 pm

Nick, did you do anything to the drains around the exhaust valve spring bases? John and I were chatting about this . J mentioned relieving the lower edge of the drain a bit so there is less of a puddle, certainly room for a bit of dressing as stock.
I have an oil leak at the OPRV as it sits, hasnt even run, so this needs investigation. I used Cu washers ,was thinner Al and paper before. Once the lathe is running the O ring mod will get done.
Posted By: Allan Gill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 10/03/16 3:04 am

Originally Posted by gavin eisler
Nick, did you do anything to the drains around the exhaust valve spring bases? John and I were chatting about this . J mentioned relieving the lower edge of the drain a bit so there is less of a puddle, certainly room for a bit of dressing as stock.
I have an oil leak at the OPRV as it sits, hasnt even run, so this needs investigation. I used Cu washers ,was thinner Al and paper before. Once the lathe is running the O ring mod will get done.

I dressed my oil in frame heads up, the casting isn't as well finished here as it is on the earlier heads.
Posted By: JER.Hill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 10/05/16 8:34 am

Hi Gavin

I looked out the old style OPRV and checked a spare set of cases, the bleed off hole is 0.125" ID. I have a few 4mm grub screws which would fit if/when you want to do the modification.

Posted By: GrandPaul

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 10/05/16 10:32 am

I don't know much about cameras, but if your camera has a setting that is indicated by a little "tulip" / flower icon, that is the MACRO setting for nicely focused close-ups.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 10/21/16 6:40 pm

Back on it after a wee interlude, as you may have guessed i have been somewhat distracted by the new lathe
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and some porpoise hunting in the Clyde, turns out there are loads, new hydrophone tech from St Andrews Uni and a systematic sweeps are revealing 1 mini whale per 8.5 km travelled on average. Spotted a sub too. The weather was fair but pretty breezy, up to a 6 ,Campbeltown harbour looked like a snowdrift with all the sheltering seabirds.
not waving the butchers apron. Saltire only.
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Barrels prepped with Copper coat sealer.
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Head fitting tools and fasteners
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Fitted studs to tapped holes in 2mm freshly annealed gasket, O rings in drains.
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The head is on

Pushrods in, the spanner tip on the rocker arms was a belter, thanks NickL
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My mechanic caught in the wardrobe, thumbs up and sporting his new BSA shirt, he has similar tastes to me but is a poor reflection of the real thing.
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Carbs and pipes the morn, got some talc to find the oil leak, think its the oil pipe manifold, tried to seal with chain X rings, fail( I think). getting close now.
Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 10/22/16 8:06 pm

Dusted the erse with talc, oil manifold, changed the X rings , one looked a bit distorted, fitted O rings from a selection box, flushed the sump, boxed it up , filled it , a local rock n roll band later and nae drips,Paint it Black was excellent. sorted. Carbs dont go click click, Clutch is smooth, all controls in order, just got the tank and chaincase to oil up, scabby old pipes went on with " Sticks like shite" the silicone mastic under the sink which I had been saving was solid. "Sticks like shite" , will hopefully live up to its name, kick start doesnt go Clang either . Tank and fuel in the morn.
New pipes would be good, if any one knows of a supplier of late style balance pipes that actually fit I would like to know . The current set were "adjusted" and are showing their age a bit.
Posted By: TR6Ray

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 10/22/16 8:51 pm

Yep, good luck with it Gavin.
Posted By: JER.Hill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 10/23/16 2:25 am

Hi Gavin

Your lathe cleaned up well. Good luck with the start-up.

Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 10/23/16 2:17 pm

Getting the bike out of the house was lie a weird reverse form of pupation.
4 ninety degree bends in less than 15 feet. After removing the loudencers, the rear number plate and the brake pedal it squeezed out.

Re assembled.
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Fueled ip, fixed the usual leaks, LHS tap union, LHS pipes were loose and LHS float bowl gasket nipped up. Good to go.
Spitting back on kick over, hmm, volts were a tad low, put on charge and polished the wheels for a bit.
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More than 12 volts, still spitting/popping hmm. Reversed the pickup wires.
Ran on first kick ,yay ish, but not happy. Pulled the LHS carb to check the cable and needle were OK. All good, then I noticed the absence of the balance pipe, Bingo, fitted that and away it went.

Set off on a wee run to the filling station, got to the x roads and the gear pedal fell off, Numpty,
refitted same correctly and off we go.

As before needs choke for a couple of miles, up the box, forgetting I have 5 gears and start cursing the LBS for supplying the wrong Gbox sprocket felt like 20 / 47, then changed into 5th ,this will take a bit of getting used to.

Running fine , but a bit spitty coming off the pilot range, will try number 3 slides.

Motor is a bit quieter than before, possibly smoother.

The clutch isnt right,getting drag , after a few miles a lot of slack appeared, needs some investigation, suspect the end plate adjuster is out of whack.

Gearbox is great going up, but difficult changing down, suspect the return spring needs adjusting.
5th to 4th OK, 4th to 3rd not good, works after reselecting.

Forks, the best thing about them is I cant tell much difference, less dive on braking, no funny noises, handling well on my favourite bends.

The kickstart lever is still the old one, need to mod the lever spindle to get the LC one to fit.
The old one is still clanging off the loudencer.

Bike smells weird, the SLS has an unpleasant smell, but seems to be doing its job, hopefully this will cure after a few heat cycles.

Turns out SLS has a max temp of 100C, that will be the smell then, will get Silicone in town tomorrow.

No oil leaks. But the cheapo running in oil has an unfamiliar smell.All electrical systems functioning well, although with the lights on the voltage indicator isnt green at 3.5 k.
Sits at 60 mph with the throttle just open.
Oil light coming on at idle speed when hot, using 15/40 cheapo oil, when cold the oil light clears when kicking over, so no change there from previous.

Pics after first shake down run.

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Just spotted something in the last pic, the boyer has freed itself from its velcro mount, bugger, its dangling from behind the RHS side panel.
Still using the NGK plugs which were recovered from the bin at the LBS.

Posted By: gavin eisler

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 10/23/16 5:25 pm

A summary of things I found wrong on the rebuild.


Bottom motor mount shim was missing.Wouldnt have known if I hadnt read about it here.
Handle bar rubber mounts incorrectly assembled, thanks to Stuart for pointing this out.
Fork stanchions worn,chrome gone in thrust zones.
Swing arm spindle dollies , rust damage.
Centre stand wrong length (T140),one inch removed, very easy to use now.
Head steady missing the correct trapped nut, very easy to refit with the correct item.
Fuel tank centre mount FUBAR, repaired and now stock .


Drive side main shaft worn. One of the reasons for strip down.
Exhaust Rocker spindle had a mashed final thrust washer, wrong one fitted , should have been the smaller ID size.My fault.
Timing side bearing had rust damage on a couple of needle rollers.
Oil pump mount not flat.
Worn idler pinion spindle,replaced pinion,bushes and spindle.
Worn clutch centre hub, replaced.
Crank dynamically balanced, and big ends reground to -20.

Good suppliers, Grins triumph OIF stuff, tank mount, head steady nut, control levers, various fasteners.
SRM, quality spares, good info and back up.

Terrible stuff, nearly everything from Wassel, swing arm dollies wrong size OD and ID.Clutch thrust washer, too thin and wrong material. Rubber bits that are made of self dissolving rubber.

Amazing stuff.Many many thanks to John Hill And John Holmes ( Kommando) for providing well engineered special stuff, a pleasure to deal with these men who have both provided me with great back up info and sold beautifully engineered products which are almost unobtanium.

Some chrome ware replaced, lamp bucket, brackets and rim , all Wassel, the brackets barely fitted, the rim and bucket are less robust than the originals, time will tell.

My home brew plating, not bright , , but not rusty, time will tell.
Tank repainted, the painter was local, didnt know about the filler neck, at the first fill I had to remove all the peeling paint from the filler ID, woops, i hope I got it all.

Remaining scabbiness.
Front mudguard,weld repairs and spotty chrome,hmm. the repops have a 3rd vertical stay which holds the guard up too high, the old one may get re-plated.
Exhaust system, showing its age, years ago when it was new I had to cut the LHS balance stub off and reweld it in the correct position, I may commission a new set from Raysons in the UK and send the old ones as patterns.
Ally rims/spokes, there are a couple of dings in the rear flange rims from difficult tyre fitting, when the hoops wear out I may have these rebuilt and tweaked .
Both hubs have very tired looking paint.

For now I want to ride it, the new first gear meant getting up my drive a far less traumatic affair than before. Once the down change/clutch and carbs are set its going to be a huge improvement.Also looking forward to playing with the fork damping settings, first impressions are that they are pretty close, need to try crossing some cats eyes with a bit of lean to see how they react under pressure, potholes aplenty around here so it wont be long before I get some "feedback".
Weather is fair at the mo , must make the most of it.

Posted By: Adam M.

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 10/23/16 7:48 pm

Looking good Galvin, I know you get it right as well.
You just need some more time and more riding.
Posted By: TR6Ray

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 10/23/16 8:13 pm

Originally Posted by gavin eisler
Weather is fair at the mo , must make the most of it.
Yes, you have certainly earned it. By all means, get out and ride it while you can. You've made a long laundry list, but none of it sounds too drastic. All in due time.
Posted By: JER.Hill

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 10/24/16 1:07 am

Hi Gavin

Great to see that your up and running, few initial niggles but none that sounds anything other than fettling after a major rebuild.

Hope the weather holds for you, been wet over this side all weekend.

Posted By: kommando

Re: alloy barrels + 5 speeds A65 750 OIF 1971 - 10/24/16 4:03 am

Its been a long road but great the good weather has allowed you to get the ride in so late in the season. Great job and the forecast is good for the week ahead.