Britbike forum Forums British Motorcycle specific Brands Bsa bulletin board Firebird Scrambler - Working to finish up

Looked back at my old messages and it's been a damned YEAR since I last made progress on putting the top end back on this bike. It needs to be up and running for the TSMR, and time's flying.

In the meantime, I did install a new Indian-made rear fender (seems to be good metal and chrome, proper rolled edges, had to "mill" some of the mounting holes to make it all line up but that might be a combination of the fender and the bike), a chainguard that I bought years ago from Alex, and a few other bits and pieces.

Now I'm working with a brand new set of .020" over pistons and rings and a swap-meet cylinder that's been bored and honed and measures .020" over.

The ring gaps are .011", which is in the .008 - .012" range for new rings in the book. The new wrist pins are a proper heat-piston-to-fit clearance in the pistons, and a play-free slide fit in the conrods. I'm measuring-twice-cutting-once on the piston-to-bore clearance. The pistons are, of course, oval, to allow for differential expansion across the small-end bosses. I measured bores and pistons and calculated tonight till I got buggy-eyed, so I'm going to hold off until tomorrow before fitting everything - want to make sure I don't seize the thing up.

Sent off several cables from this bike and my C15S project to Barnett, including the levers that I'm using, so that they can make up matching ones. Going back and reading up on what kind of dual-sport tires that Semper Gumby uses on his Firebird - the K70's I've been using wear out very quickly and aren't all that great on either road or dirt, despite the fact that they've been my go-to Brit tire since 1973.

Actually putting in some quality shop time between this and the C15 ... and I need to get stuck back into the TSMR Norton, which goofed on me about 200 miles after the rebuild, right when I'd done the third head retorque .... It really helps when I keep the shop clean and organized and all the tools put away. It's amazing how fast that will get away from you if you don't keep after the cleaning and organizing.

Lannis

Funny how hard it is to get back into the mood on a stalled project sometimes. It seems like once you touch it, the feeling comes back pretty quick! Sounds like You’re on a roll ! 🛠 🏍

Measure twice, cut once, they say, and now I'm convinced that the pistons, rings, and cylinders are compatible and will have the right piston-cylinder clearance and ring gap when running. The tappets are smooth and tight in the bores, the cam follower surfaces smooth and unworn after all these years, and a little grease will hold them in the bores without the little C-clips while I'm lowering the cylinder down.

Checking with the panel one more time .... 2023 wisdom is still "bores and rings clean and dry for initial installation"? Always feels funny to me to assemble moving engine parts with no engine assembly lube, but I do understand about "breaking in" the rings to the bores. Don't want it burning oil until it's worn out .... !

Lannis

Ok, here we go.
I myself lightly oil the bores, I do not oil the rings, and I do smear some oil on each piston skirt. If you do it this way and then after assembly rotate the engine a few turns before you put the head on, you will see a small ring of oil near the top of the bore. That is the left overs. The rings get just enough lube and scrape the rest toward the top of the cylinder.

This is what I do these days. I oil the skirts but not the rings. Otherwise you end up with metal to metal contact until oil has found its way up the bore.

I started off building my motors like this, the first bantam I did was liberally oiled and it ran really well. I can’t say it never smoked… it was a bantam.

I later fitted them dry, I ended up with full thrust faces (not scratches) on the pistons and in some cases they wanted to nip up.

Your oil control ring will scrape off most the oil till it’s bedded in, I also don’t think there’s such thing as a quick break in.

Lannis,
Is that the motor I worked on many years ago? It should still be running!!!I I used assembly lube about everywhere there was metal to metal contact. Somewhere out in the shop I have the rebuild specs on that motor if it's the same one. I did my A65 motor about the same time as yours and it is on its second owner after me and still running great. The new owner emails me from time to time with "How to" questions.

Pretty soon you will be up in age where I am now. I only have the B-50 left, the others have gone on down the road.

Mr Mike

Same motor, Mike. Bottom end is still good, but it developed a "piston slap" that was annoying and getting worse. Ring gaps were .028" and up, and bore clearance too high. It probably had 20,000 miles on your/Ed V's top end so that's still pretty good.....

Lannis

What Ive done on a couple of bored barrels because i JUST CANT reassemble it with no oil ... its a blockage for me. When i got out of my business i had some cutting oil ( used on automatic lathes etc as coolant) ,, it is designed to keep the machine flooded with oil but give a good cooling medium for the tooling.

So i used a fairly liberal amount of that in the old school fashion, seems to work well ... smokes like a train for 5 seconds then calms down as the bikes oil supply takes over. I dont recon it will prevent breaking in as it is a cutting oil .. and it makes me feel better. At least i dont visualize dry rings taking thousands of mile of life off the pistons/rings/bores with a dry start .

I do it "pretty dry." Usually I am doing this after a rebore or honing, so the cylinder gets washed pretty thoroughly. Then, because its rare that I am immediately ready to install, I oil the cylinder so nothing rusts. When it is time to install, I wipe out the cylinder, but I don't wash it again. So there is still some residual oil. I just put a dab of oil on the front thrust face of the piston and thats it. Nothing on the rings. I have never had any problems, except once on a mid-90s Ducati. I was helping a pal re-ring his 750. He is old-school and wanted to slather everything in oil. I told him that is not the current thinking, so we did it "dry." A ring broke as we were putting the cylinder on. He attributed it to putting it on dry and then said the Ducati handbook said to oil everything up. I attributed it to the lack of proper ring compressors. We were using hose clamps and I think one wasn't tight enough.

Hey, are the Shocks going to work on the C-15?

Ed from NJ

OK, since others have admitted their process, I will join the parade. I oil the crap out of everything, turn the crank over a couple of times, and wipe out the excess at the top before head goes back on. And by the way, that might be days or weeks later. In the meantime, the oil is protecting exposed parts. I do this to avoid fouling the plugs at the very beginning. Not sure how I have gotten away with it, but no oil burners here.
Oh, and all of that information about speeds and push it hard at the beginning…..?? Again, fools luck, I guess. 🤪 🛠

Hey, are the Shocks going to work on the C-15?

Ed from NJ[/quote]

Ed - Yup!

[quote=edunham]


The bottom bushing on the shock was a 3/8", which is usual on BSA singles early and late. On this "competition" frame, the bottom bushing is 1/2", and mounts to a stud made into the swingarm. I tried drilling out the 3/8" ID to 1/2" on a drill press, but that was never going to work - the rubber is just too wobbly. So I found a pair of NOS 1/2" bottom bushings, pressed out the old ones, pressed in the new ones, and for the cost of your generosity, shipping, and a couple of bushings, I've got a lovely new pair of Shocks .....

Lannis

my issue with the assemble dry then ring the tripe out of it brigade ( unless u have bored it to "racing clearances" ) is that u cant possibly NOT decrease the miles u can expect from a fresh bore and pistons.

The question is, then, by how much? Like, every time your engine turns, your ignition points cam turns and wears down the rubbing block. So no matter how well you set your points and dwell, it's all wrong, and getting worse every second, every second that your engine runs ....

Lannis

No-one ever suggested you "assemble it dry and thrash it"
A wipe of oil in the well honed bore and a brisk ride of the bike
is basically all they got at the factory. Testers never babied the engines,
to bed them in they must have the rings loaded or you just glaze the bores.

assemble dry and trash it has been suggested OFTEN on this site ... not saying on this thread but that does seem to be a line of thinking

There seems to be a slight misunderstanding.

I've used this example before but here it is again. A piston aircraft engine break-in is 1 full hour at low altitude and wide open throttle. This is to seat the rings. Obviously, nobody is going to do that to an old BSA; they aren't designed for continuous WOT, but it illustrates the point that rings NEED high cylinder pressure to properly seat.

I know that I follow a procedure that could be called "dry and thrash" but the rings are the ONLY part that is assembled "dry". The rings then get what little oil they need from the lightly oiled cylinder bore. Everything else in the engine gets some type of assembly lube.

As far as "thrashing", I don't baby a relatively modern street engine to break it in. It gets ridden briskly with occasional third to half throttle roll-ons or mid range pulls through the first 3 gears and then I back right off and just cruise to let things cool. Then after a few miles I do it again! I do NO sustained hard up hill pulls or sustained high revs. The first few rides are fairly short so the engine can cool down completely and any small problems dealt with. You need the cylinder pressure to seat the rings but it's also important to keep the heat down.

If your overhaul clearances and tuning are good, this kind of break-in works just fine.

I put top ends together “dry”. Been doing this for a very long time. I learned it from a former Triumph dealer who built some fast Triumph flat track and drag bikes.

Ronnie Jones of Stark Triumph built his top ends dry. Carefully hone and clean everything. He claimed they got enough oil from your fingers during assembly to be ok.

And his break in procedure was special too. Didn’t matter if it was a street engine or race engine, he would pull the bike out of the shop, start the engine and let it warm up and make sure oil was circulating. About 1/2 mile or so from his shop was a small tavern, once he could feel heat in the cylinder, he started from a dead stop and pinned it through the gears to the tavern. Turn around in the parking lot and repeat the process back to his parking lot. Roll the bike inside, put it on the lift and check it over. After it was cool, retorque the head and it was good to go.

He built some of the most reliable race motors of the era around here. And reliable street motors.

I have never been able to bring myself to use his break in procedure, but I don’t baby them

"Dry" as I understand it means the slightest smear of oil on the bores and on the thrust faces of the piston.
Nothing on the rings or the piston non thrust faces.
When we were racing in the 60s we would very often arrive at the track with a motor that had finished rebuilding at midnight the night before.
Break in was two laps riding hard but not 110%, then change the oil and ready to race.
Never had a seizure or smoke!

Upon mature reflection and consideration of all of the experience presented here, I decided to go basically this way. No oil on the rings, a very slight smear on the bores.

Annealed the new head gasket this morning .... on a gas stove with an infrared thermometer to make sure that every point on the gasket reached 450 - 600 degF, now to buff off the oxides and combustion ash and roll along ....

Lannis

Glad to hear the Shocks are going to work out! I heat copper head gaskets till they are cherry red on the stove. They are nice and soft then.

Ed from NJ

Lannis,
I do not over lube anything but everything gets a light smear except the rings. One of the changes I had on my bike were small drillings in the rod to squirt more oil up into the bore. I read about this but of course you never really get to see if it helps once the engine is assembled. The materials in those days are not what they are today. I had piston slap in one of my b44's after about ten thousand. It ran good but the noise drove me crazy so I rebored. I always would send pistons with the cylinder on rebore jobs to make sure they it comes out on the lower end of the tolerance range and hopefully a longer life span

Mr Mike.

Sorry about the hijack but, Nicholsons recommends .0025" clearance on a street ridden B44 as being invariable the way to go. But a B44 that is raced or ridden hard should get the .0035" clearance. My current B44EA engined bike has .0035" and it is noisy unless I am riding it hard, then it quiets down. Other B44's I've had in years past were bored to .0025" clearance and were much quieter, and I never had one seize on me.

There is a Service sheet on the drilling, can’t remember the size but it’s pretty darn small. The set of rods I fitted into the Thunderbolt didn’t have them (aftermarket rods) so I marked it all out and drilled it though and cleaned it up. When I primed the pump and the crank (with the cylinders off) oil would clearly weir from the hole, so I can imagine it will be quite a jet of oil when the engine is running.

So this is pretty embarassing, considering the number of times I've taken heads on and off of A65s. As far as I know, I always take off the heads before I take the engine out of the frame, and I think I did it with this one, but ....

I've got the engine back in the frame, pistons in, cylinder block on and torqued down, and head ready to go on ...

... and it won't go on. There's no way that the front center valve cover stud will clear the top frame tube so that the head will slip down over the head studs. I swore that's the way it came off, but maybe not. I have two other heads on the shelf, and neither one of them has the front center valve cover stud in place.

I'm not positive that the head I got back from the rebuilder is the same head that came off the bike, as I told him to just give me a good rebuilt Firebird head back, so the one I sent may not have had the stud on it.

At any rate, I'm sure I've never pulled a stud out to install a head .... so

(1) Am I missing a trick and '69 A65 cylinder head will install with all six studs in place if you hold your mouth right and say the right words? Fay and I puzzled over it for an hour today, and no way.

(2) Do folks pull that stud, and just use a bolt for the front and rear valve cover fastenings instead of a stud? I tried pulling this one with two nuts, but it's going to have to be destructively removed, it's not coming out that way.

I can't believe I don't already know this. I have 4 different BSA A65 shop manuals, and none of them say anything about it ....

Lannis

I know virtually nothing about BSA twins, but …. (and this is not knowing much about the actual circumstances) if the stud won’t come out with the double nut method, then it might just want to snap off when you use another method. Maybe worth trying some localized heat and give the double nut another try? There were a couple of occasions where I wish I had followed my own advice about using heat.

Lannis,
I have pulled a stud to get a motor in but unfortunately don't remember what bike it was on. Don't like to do it especially if the stud is in real tight. I replaced all the studs with bolts on my B50 so I could get the head off with the motor in the frame. I went to all that trouble and have never had to remove the head again.


You might try the oil pressure mod I used on my A65. It is listed above and really easy to do, Ten years later it still has great oil pressure according to the new owner. I might have one of those little OPRV's I used. It's free for the asking.

Mr Mike

You may be able to buy some wiggle room by removing the cylinder head studs, , fit them loose in the head, offer it up , then use double nuts on the studs to seat them home.

This is supposed to be encouraging comments. Hopefully it comes out right. It's just that it's reassuring to know I'm not the only one that gets stopped dead on my projects for who knows what reason. Glad to see you've gotten yours started again. (Now maybe I'll do something about one of my projects.)

I agree 100% with this. That stud may be red loctited in there and 300 deg of heat will soften the glue so the stud can turn easily.

Gents -

Thanks for the Propane wrench advice, it worked. When I heat up something, I have the torch or heat gun in one hand, and an infrared thermomter in the other to make sure I'm not doing something stupid. I had pulled pretty hard on the double nuts, and my mechanical sympathy said that I was within a few inch-pounds of tearing out the threads on the pulling nuts.

Got out the propane torch. Playing the flame on the boss into which the stud screws, I got it up to 234 degF after a while - of course, heat is flowing away into the rest of the head as fast as the torch can input it, but at 234 I tried the wrench again, pulled as hard as I dared, and it came out like a fairy.

With that stud out, you could stand a foot away and toss the head on the cylinder and it would go on. Bolted in the head, and decided to go ahead and re-install the stud, knowing that if the head has to come off again, the stud will have to come back out. Next time, I will have a thread insert and a bolt ready; steel studs screwing in and out of aluminum threads isn't a formula for long-term success.

Lannis

Do yourself a big favour and fit a bolt instead of the stud. If you have a lathe, you could make one with a deeper head which will aid removal another time. I would also have helicoiled that post.

That's good advice, but if I keep on doing myself favors on this bike, I'll never get it back on the road. I started out pulling the top end to fix a piston slap, then pulled the motor and stripped the frame to reweld the side stand lug, then did some rewiring, then decided to buy a new chain guard and rear fender to replace the cracked originals.... And the stud screwed back in smooth and tight, so the threads aren't buggered, so it's It'll Be Right, Mate this time around....

Lannis

At least use some copper anti seize paste on the threads, they should come out easier next time.

On my A65 Firebird, I replaced the studs with stainless socket caps and helecoiled the threads, so the head is easily installed and helicoils ensure they can be tightened without fear of stripping.h

OOOHHH bloomin heathan

Reinstalled the pushrods and rocker arms this evening, after all these years I've never acquired the knack of quickly and gracefully feeding the rocker arms shafts through the left outer boss, the thrust washer, the left rocker arm, the spring washer, the thrust washer, the center boss, the thrust washer, the right rocker arm, the spring washer, the thrust washer, and the right outer boss.

Now that I've written it down, no wonder the shafts take 15 minutes each to install.

Lannis

I think it’s a dexterity thing. 10 years ago I could fit them much quicker than I can now. I seem to drop one of the washers down behind a valve spring quite often now taking more time.

Yes, my little magnet on a stick came into play several times....

I don't remember having to pry the valves open about .050" to slip the pushrods in place, even with the adjusters removed and cam in the right place, though.

Lannis

Cleaning and rebuilding the carbs, using new Stay Up floats even though the old white plastic ones were still floating, there's a limit as to how far I want to push a piece of plastic that's been marinating in gasoline for 54 years .... !

Cleaning up some of the wiring, installing a proper in-line fuse holder rather than just a blade fuse between two female terminals, found the proper 3/8 x 1-7/8 x 26 TPI bolt for the bottom rear shock mount, replacing all the worm-gear hose clamps with oetiker clamps.

Time for one more parts order if I need it before the TSMR, if I find out I'm missing something!

Lannis

Finished up the carbs this evening. Made a little fixture and rigged up some tubing to set the float height; just fixtured the bare float bowl into a vise, leveled it, put the float and needle in place, gravity-fed fuel into the banjo until the valve sealed, and measured the height of the fuel level from the top of the float bowl.

The specs say .21" +- .04 from the top of the float bowl to the top of the fuel level. So I set that for both carbs (you can bend the tabs on the newer floats, unlike the old ones where you had to heat the bowl and drift the valve seat up or down).

But when I put the bowls onto the carb bodies, I realized that the standard gasket is .040", which means that when the bowl is bolted on, the fuel level will still be .21" from the top of the bowl, but spaced down from the jet by the .040" thickness of the gasket. Does the .21" spec take account of the gasket thickness when determining how far the jet will be immersed into the fuel? Never have thought about it before .....

Lannis

I'd think it extremely unlikely that nobody at AMAL would have thought to allow for the gasket thickness in all the years they've recommended measuring from "...the top edge of the float bowl".

My bigger question has always been "do you take the angle of the carbs into consideration"? You measured in a vise, but some people do this on the bike, where the fuel level is higher at the front of the bowl than the rear. Then, what about the center stand? Front wheel down or rear wheel down? And finally, the new premier carbs don't recommend setting the float height at all; why not?

That's to say, there are so many variable and everyone reads the guidance a bit differently. I would assume that the margin for error would be greater than the thickness of the gasket, but I can't say for sure (assuming +-.04 is set low to ensure the end user gets within the true margin)

Meanwhile, the two premier carbs I purchased came with floats sitting at two different levels (visually, didn't measure) and I've never set them due to the recommendations from AMAL.

Do you have a reference for that recommendation?

From what I've read from L.A.B. and kommando, the fuel level is critical relative to the main jet, so you measure at the middle of the bowl, front to back axis.

Well, I measured it at the middle of the bowl with the float bowl level front to back and side to side. If I tilt the bowl to (about, via eyball) the angle that it will bolt onto the head when the bike is going down the road, that measurement doesn't change at that point.

So I think I'll just go with it the AMAL time-honored measurement, and not try to second-guess what the fuel level might be doing as the bike leans, or goes over bumps, or moves around under acceleration or braking. I need to go back and read (at my leisure) the past discussion and explanation that I remember that John Healy has done regarding the effect of fuel level on mixture. I understand hydrostatics to some degree, but it's hard to imagine (although I believe it's true) that a few thousandth change in fuel level will materially affect the rate at which intake vacuum will suck fuel up the jet. I better get my physics books back out. Meanwhile I think I'm "close enough". Besides that, I'm using my "go/no go" gauges to verify the .106" dimension on my installed needle jet, so that's something ....

Lannis

That go no go gauge will serve you more help than anything else.

Lannis,
I did the same thing as you with carbs in a vice to set float height. Honestly, I found that float height is not as critical as some make it out to be. It's job is to keep the bowl full of fuel w/o flooding the engine. You can run the bowl nearly dry before the engine sputters.

I once had the float stick open out on the road.. Pulled the bowl off alongside the road and the float was full of gas. I put it back together, turned on the fuel till gas came out the tickler hole, shut off the fuel and ran till it sputtered, then turned the fuel back on. Made it all the way home repeating the procedure many times and the bike did just fine.
Mr Mike

The actuaal height is not as important as both being the SAME height or you will never get them to sync .

I've officially had my fill of AMAL carbs.

Lannis

Lannis et all: The thickness of the AMAL 622/073 float bowl gasket as originally supplied by IMI AMAL, and now supplied by Burlen, is 9mm (.035"). Inlet angle for MK1 1/2 and MKII carburetors is limited to 15°. Any more than that and you need to move the pilot jet position.

The original Concentric MK1 was designed and jetted for use on two stroke engines. This led to the development of the MK1 4 stroke version. It is important to understand which instrument you have when buying and tuning your bike. A 4 stroke condition kit was made available (622/235 - new needle jet (622/122-.106), new needle jet (622/124 - 2 ring needle) and 622/128 main jet holder).

Then along comes the after market where people were having parts made wherever.
Needle jets were under, or oversize (A .106 would measure anything from .104" (or less) to .109" (or more). The 622/128 threaded hole for the needle jet was not counter bored properly and when the jet was tightened it would crush the orifice of the internal jet and close up the orifice. The air bleed on the hex portion of the 4 stroke needle jet, which should be .035", was not properly sized or deburred after drilling. Small variations in the orfice dimension makes a big difference while the straight portion of the needle is still in the needle jet's orifice.

In the early 1990's when Barry Johnston retired, IMI transfered the AMAL license to Grosvenor Works. Grosvenor already had a working relationship, being one of their outside suppliers who manufactured parts AMAL Series carbs and Bunsen burners. David Holder (Velocette Motorcycle Company) helped them finance the production of pre-MK1 carburetors including the Monobloc. At the same time (early 1990's) the UK government banned the product that was used to glue the top of the white float to the cup body. This put a whole lot of production carbs and spare parts on distributor and dealer's shelves. Before Burlen took over the distribution of AMAL products another run of white plastic floats were made. This time the product to bond the two plastic parts together worked and the floats didn't sink from leaking fuel. Both of the latest standard 622/079 (shallow) and 622/196 (deep) floats work as originally designed: they don't sink. It is interesting to know that Kenny Dreer found that on his VR880 Norton, with MKII Amals, they ran better with the 622/196 deep float.
As a carburetor, the MKI and MKII are very easy to tune. I find that typically anyone who cannot get an AMAL to tune will have the same problem tuning other brands. And don't forget that anything that changes the air velocity in the carb's venturi will change the air fuel mixture. Change in carb with different diameter venturi (going from a 930 (30mm) to 932 (32mm); modifications to port intake diameter; changes to cam timing; changes to cylinder bore diameter; ai intake leaks; changes to exhaust system's type: (pipe diameter, length of system, muffler, straight pipes, megaphone, etc.) condition of the rings and there ability to pull a vacuum; etc.. Failing to understand that the air and fuel orifices are not just a hole but react to all of the principles that make them jets as is the straight diameter of the needle (.0985").
And coming to the understanding that you MUST know which fuel circuit is in play to analize where your problem with the CARBURETOR (not all of the other things that effect Bernoulli's principles). Mark the throttle that is illustrated in a Mikuni manual. And remember that the jetting for each stage overlaps, and many flow charts illustrate how a Mikuni is tuned where the tip of the needle DOES NOT clear the needle jet.
While in some cases the fuel level in the bowl can effect performance it is usually not that critical. It is more important that the float bowl screws are not over tightened and causing an air leak in the fuel transport drilling in the float bowl gasket surface!!!!!!
Now back to work getting orders out!

We've gotten a lot of good advice over the years on tuning MkI Concentrics. I can usually get them to run like I want. I have the plug gauges for the jets, I know how to set the float level, I know how the pilot jet, the needle jet, the slide cutaway, the needle position, and the main jet interact at various throttle openings, and can recognize surging, popping on decel, blubbering on acceleration, how to use the choke to determine if jet size is off, I know how to set each side with a plug wire pulled to tune a twin like two singles, I can use two sticks to sync the carbs ...

But I get tired of the cheap cheese-like material that they're made of, and I hate that weak split ring that the Concentrics use to hold the needle in the slide, not like that robust clip that the Monoblocs used.

I took the two 928 carbs off the Firebird 8 years ago when I took it down for a top end job and a few other things. Just bagged them and laid them on the shelf. Left the slides on the cables and bagged them in a plastic baggie on the bike.

When I went to clean, rebuild, and assemble them this past week, the slides would not go down the bores. I had not bolted up the carbs and distorted them, I had cleaned them up nicely, put new Stay-Up floats in, set the float level, replaced all the soft bits, checked for jet wear and gently screwed the float bowls back on. But when I went to check the slides for play in the bore, they would NOT go into the bores without more force than I was prepared to use.

These were #3 slides that I had been running for some years. I want the bike up next week, and had no time for new slides, sleeving bores, etc. So I got out the (stock) #2.5 slides that I had, and they would BARELY go through the bores with a push.

So I spend the next two hours with a tube of Prussian blue, a big pair of Channel-Locks, and a bare slide, and squeezed and checked and massaged the bores until the slides moved freely. It's amazing how weak that carb body metal is. As I gradually got them round, I could put the slide in the bore and it would stick. I could barely touch the body with the pliers and the slide would drop ... pretty soon I could do it with my fingers.

If I find out that the Norton's problem (quit on the road on me last fall) is one of the carbs, I'm going to bin both of them and go to a single Mikuni. Dynodave, I know that your philosopy is "Learn how to fix your motorcycle so it runs right rather than buy your way out of it" and that's a good philosophy, BUT I'm getting too old to learn to get to be a world expert on a carburetor rather than riding my bike.....

Lannis

I upgraded the wiring a bit. All grounds (headlight, taillight, Boyer, Tympanium, Dyna-Coil) now run to a single point 4 inches from the battery positive terminal, and a fuse in that. I thought I'd done a good job when I took it apart documenting how I did my wiring (for example, I'd forgotten that I'd run wires from battery negative straight to a pair of relays in the headlight bucket for the high and low beams), but I didn't, and had to dope it out again with an ohmmeter. New AGM battery.

The cylinder head that went on it was not the same one that came off, so I spent several hours today refitting the exhaust. The Firebird high pipes have to go in together, and bolt together in two places, and if the header pipe won't go ALL the way into the exhaust port, the holes don't line up. So I spent time with a Dremel tool cleaing up the exhaust ports, and trying and retrying the header fit. Finally got it to a nice tight fit and the bolt holes lined up.

But because the positioning was a little different, the H-pipe and rear silencer mounts didn't line up any more, so more bending and adjusting and I need some different bolts now, luckily they're hardware store items and I can get them tomorrow.

All First World problems, it's not like I have to figure out what to eat tomorrow or go hungry, but still ... you want to do a good job and have a bike to ride!

It's just that things seem to take forever sometimes, like nothing works the first time around.

Lannis

for 900 series carbs. Burlen are now selling Aluminium boddied ones. I don’t think they are listing the Mazak ones as a premier option anymore. But I just ordered and fitted a pair of 930’s to my friends OIF Lightning and they are really nice, the quality is apparent with them.

That's probably the right thing to do,and would address my current gripes with the originals.

Re-equipping my Brits running Amals with nice aluminum Burlens would run north of $2100, though, so I guess I'll have to start saving my pennies. Although I'm six-hundred-dollaring myself to death getting the Firebird and the Norton and the C15S back on the road; nothing's cheap any more.

Lannis

Filled it up with good 'ol Castrol 20w50 after spinning on a new oil filter (I have a Mr. Mike filter conversion where the filter base is welded to the rear engine mounting plates, very sturdy, unobtrusive, and easy to get to, uses a Harley filter). Put it in top gear and gave the rear wheel about 20 full turns, and oil started coming out of the rocker feed and tank return, so that system is working.

Now into town for some silencer mounting bolts, and we'll see if she'll run later on.....

Back from town, got the right bolts for the silencers, put it all together and realized I had the H-pipe on backwards and couldn't bolt up the heat shield. It goes much quicker second time around.

Worried myself about the spark, I couldn't get a spark from the Boyer either turning the ignition on or turning the engine over. Probed around looking for 12 volts to the Boyer box, and that was all fine. Went back through the old Boyer Troubleshooting Posts on bb.com and realized I'd forgotten that even though this unit is 18 years old, it's a Micro-Mark IV and doesn't spark when you turn the key on, and neither does it spark under 200 RPM. Gave it a "Long Swinging Kick" and got sparks.

Cleaning up and changing the primary and gearbox oil this evening. I've FINALLY put two proper petcocks on this 2-gallon gas tank - all these years and all these long rides and I've been doing it with petcocks that both have standpipes in them, so you can never use the last inch of fuel in either saddle - well, you can use one if you laid the bike on its side. It's silly sometimes, the things up with which we put. I want to see how much usable gas is really in the tank and the reserve, so I'll do some filling and draining into marked containers.

Lannis

Had to knock off early tonight. After dark, a little lost hummingbird flew into the shop, got confused by the bright lights, and couldn't get back out and started flying into things. I had to open the big door and turn out the lights, and hopefully he'll see the dim light outside and head for it.

The fuel tank takes a little over 2-1/2 gallons, and has a 2-1/2 quart reserve, so that's good to know. Still means about 90 miles between planned fuel stops, but that's not too bad - I can get to Toronto OH from home with 3 gas stops for the 380 miles.

Tomorrow I'll know whether I'm riding it or not.

Lannis

Hey Lannis,
I see you are posting up there with the best of them. Hope the Firebird Scrambler does good for you. I am not getting out on the bike much anymore. There comes a time when other things that are less risky take the place of the bikes. Haven't made it to TSMR in a number of years but i did mange to ride the course on four different BSA's and never had to come back on the truck. I don't get on the site much anymore but it sure has been an asset to all the guys (and gals) that honk around on the old bikes.

Keep the shiny side uo!

Mr Mike

Well, the little hummingbird didn't make it. I left the big garage door open all night, but in the morning I found him dead on the floor. Maybe a bad omen!

The past two days, been fighting gas leaks, primary leaks, sticky slides, throttle cables pinched by the gas tank, and any other kind of teething problem you can think of. Unfortunately, I've run out of decent 1/4" fuel line, none is available locally, so I'm using clear plastic line, which will not seal up on the non-barbed fittings on my current petcocks. I've got them crushed down on the petcocks with two worm-gear clamps each, but still a slow seep.

Checked compression (120+ on an engine that hasn't run yet, rings and valves not bedded in, so that's good to start with), checked spark (popping bright), tickled carbs, and .... no start. Tried several times, checked plugs, they were dry and didn't even smell like gas. Put some paper towels under the carbs, tickled until there was gas splashing everywhere, and six kicks later, she started. Seemed to run OK, although there was gasoline leaking from every tube and joint on the carbs, so shut it off and fixed as many as I could find. Tried again, tickled till gas was running everywhere, and six kicks later she started. This time there was less gas dripping, so I let it warm up and adjusted the idle to 1100 RPM, rechecked the sync on the carbs, and she appears to be running pretty well. With the 2-1/2 slides, she picks up instantly when I open the throttle. I shut it off, tightened up the banjos, clamps, and swage joints for the fuel one more time, and it seems pretty dry.

No reason it shouldn't start on one kick, though. Seems like not enough gas is getting into the intake to prime it.

But now the oil light won't come on ... It WAS glowing bright when I turned the key on, and went off the moment I started it, but now won't come on at all, so I'm taking a break and get the test light out. Probably won't ride it until tomorrow when I'll have a rescue trailer available.

At any rate, it's coming down to TSMR on the back of the truck, along with an Applicance to ride if she goofs on me again .... Perhaps it can be the subject of a Tech Session.

Lannis