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#829294 11/09/20 11:25 am
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Nephew Sean's lovely 'new' '68 A50 is pretty good, but it does have a heavy clutch action. I've advised him on all the usual stuff such as cable condition, lube, routing, adjustment, PCC oil. I'm wondering if It may have had heavier clutch springs fitted by a P.O.
Anyone know if there are different strength / length clutch springs for A series? Bear in mind that it's a 500cc, not a firebreathing 750!

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Having a heavy clutch is very tiring. Sometimes the springs are too tight, many guys over tighten thinking the adjuster nuts need to be flush with top thread. Not so, you need to see what works best without slipping
For me I have swapped in the seven clutch plate system. Easy pull, positive engagement.
Beautiful machine you guys have.
Richard

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The side stand needs sorting, that is an accident waiting to happen


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The cable run looks wrong, it seems to S round the frame down tube and the bend from the lever looks tight.
Big radius bends and straight where possible is better, +1 on the clutch spring comments. I am not wild about the fuel line either, it looks uncomfortably close to the rocker cover.
if the clutch cable is long enough try a big lazy bend round the RHS of the headstock, a small clip fitted to the rear LHS barrel stud can hold it off the casing.
It could be the clutch was rebuilt with 750 triumph springs , they give a heavy action, if the clutch was worn they may have been used to prevent slipping, clutches wear in many ways, once the cush hub centre wears internally they will slip and drag now matter how many fresh plates and springs are fitted.


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Plus 1 to gavins comment. Thread the cable under the bottom yoke, behind the headlight and up to the bars. Should be nice and sweeping.

Andy H, pre oif bikes do this. The centre stand spring pushes out the side stand

Btw. If both your taps are facing that way, swap them over, I often find that the thread is so positioned so they will only face one way. The should then both point backwards and you can shorten your fuel pipe to suit.

Darn pretty bike though


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Good tips mates, ta. I'm in Oz and the bike and nephew are in Washington DC, and I'm trying to give 'remote' advice.
He's been advised to check, lubricate, and re-route the cable. That will help a bit.
Good point re the fuel lines. That's a job for him.
I guess if the clutch is still too heavy he can adjust the spring screws out a turn or two. That'll be a good start.
Yep it's a pretty thing eh? He's really enjoying riding it.

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Hope the tap idea works, I did this with mine and it did.


Now let’s all have a beer beerchug

68’ A65 Lightning “clubman”
71’ A65 823 Thunderbolt (now rebuilt)
67’ D10 sportsman (undergoing restoration)
68’ D14 trials (undergoing transformation)

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Yes a handful of copper or fibre washers with the right I.D. would come in handy eh, to pack the petrol tap thread out 1/2 a turn.
Andy, I assume that the sidestand is held down a bit only when the centrestand is down? If so it wouldn't be a problem when riding so no safety issue

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Being cruel.
The clutch cable will break soon, I give it 1,000 miles, probably less.


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No Gav' it's a fair call, thanks, I'll nag the lad!

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Thanks to all for the suggestions (this is the nephew/lad/A50 owner in question): I managed to re-route and lubricate the clutch cable; it now works very smoothly. Not quite two-finger action but not far off! I had two other questions - not sure if they should be posted here or in a new thread. But I’ll try here to start:
1. I’ll be taking apart the carb over Christmas. Should I automatically replace the gaskets or only do so if they’re in bad shape?
2. Can anyone suggest an alternative fuel petcock to the Ewarts-type? I’d prefer a valve-type but am not sure which one fits.


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That's good you improved the clutch action Sean, well done.
Fuel taps. I've tried many fuel taps over the years, but I can't really say which is best.
I've had some of various types, some of which leak, and some don't leak. I have had better success with lever types than push/pull ones.
Not very helpful eh? Sorry.
I can say that the standard taps on my ol' '79 Bonneville - lever type, were good and leak proof. Also the Italian ones fitted on the later Meriden Bonnies were good.
Hopefully someone else will 'chime in'
-J

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The AMAL Concentric carb is a very basic bit of kit, don't be worried about pulling it apart.
Note positions of the two screw adjusters and the needle clip position as you dismantle it. (Just count how many turns it takes to screw them in fully, then you'll be able to get them very close when you reassemble it.

Simple clean, -no special solvent needed, (compressed air helps though you can actually use a tyre pump). Unscrew the main jet and note it's size, unscrew the needle jet and note its size, and the needle size too.
The 2 main things to look out for in terms of wear are: a throttle Needle Jet that has worn and the Needle likewise (the needle vibrates as it goes up and down in the needle jet, and eventually they both wear, though it's quite hard to see the wear).
The throttle valve (slide) itself... Look for scratchy wear on the slide and also in the bore it slides up and down in. The metal is crap and wears quickly!

I've rarely found it necessary to replace gaskets/seals, but if you go the whole hog, a 'reco kit' would do the business.

The other thing is the Float valve needle. This controls the flow of fuel into the float bowl. If it's leaky it'll flood the engine, making it run rich.
Special Float valve needles are available which have 'Viton' tips which are good.

Big tip: Don't over-tighten the carb flange mounting nuts, if you do, the carb body may distort resulting in a 'sticky' slide.
Just nip 'em up using light-ish lockwashers.

Many 'newbies' have trouble getting the throttle and choke cables disconnected from the Throttle Slide. It's dead easy when you know how!
There's probably a Youtube video on this. If not let me know.

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if you are doing carb stuff.

Buy a rebuild kit, this comes with replacement bowl gasket, float needle ( get the Aluminium viton tip type), o rings for adjuster screws, and banjo filter .

Buy a half dozen, #78 drills, these are tiny, 0.016" diam, easily lost, The only effective way to clean the pilot jet.

Mount one of the drills in a WD40 straw, and keep it in a special place/ coffin.
This one tool is the most important thing for your carb.The pilot jet is the smallest hole in the system and the first to block.

buy a replacement needle jet, these do wear.

Study the float bowl gasket face for warping, if the float bowl is an original it will predate the later type which came with a drain plug, if it is warped replace it with a later type, the drain plug is a handy thing .

Now add up the cost of a rebuild kit, needle jet and float bowl. Compare to the cost of a new carb. A new carb will only be slightly more expensive, Hmmm, throw in a new slide as well and a new carb looks like a good deal. Just sayin.

Last edited by gavin eisler; 12/14/20 9:33 am.

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since my thread scan didn’t pick it up, I’d mention that the distance between the cable barrel and the lever pivot screw can make a very noticeable difference. Looks like the levers may have been replaced in the work process.


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"Now add up the cost of a rebuild kit, needle jet and float bowl. Compare to the cost of a new carb. A new carb will only be slightly more expensive, Hmmm, throw in a new slide as well and a new carb looks like a good deal. Just sayin."

Yes, that's why I would go for the 'repair not replace' approach first. We rarely see a warped floatbowl.
Many people scorn the use of a drill to clean pilot drillings as there's the risk of opening up the holes, - an old guitar string does the job without risk.
(Just sayin') :-)

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Originally Posted by Joolstacho
We rarely see a warped floatbowl.

Then you haven’t seen many float bowls. Usually caused by hamfisted over tightening


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Poking a Guitar string into the pilot jet works , for a wee while, then the mung comes back to block the jet, using a #78 drill which is a baw hair smaller than the true size of the jet, when twisted clockwise, not only cleans the jet without damaging it but it also removes the mung which helps a whole lot more. YMMV

my own carbs on my 71 A65 are entirely original, . Apart from 2 new float bowls , 6 new slides , 6 new needle jets , 4 new float needles and 4 new bodies.
I love original. These carbs are fully rebuildable , have at it. new carbs , phooey.


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Hahaha, like grandad's axe eh... It's had 3 new axeheads and 5 new handles.


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