I have these 4 little nuts with a threaded slotted rod going from the clutch ring spring retaining nut into the clutch spring itself. I've not seen these in any pictures or in any manuals about the BSA M20 clutch. Any ideas if these are original or a field modification to keep the ring nut and spring in one piece when removing?

http://i.imgur.com/gKn7kEf.jpg


I cleaned a lot of gunk (might be oil?) off the clutch hub once I removed the bowler hat cover. Not sure if oil got on the plates and is causing a problem.

When I go to kick start the bike the kick starter just hits the ground and doesn't turn the motor over as if it is slipping. However I can turn the motor over by holding the compression release open or by turning it over slowly with the kick start pedal. As soon as I apply enough force to actually try and start the motor it just slips. Is this related to a bad clutch?

When the clutch is fully engaged the bike has a bad shake and at no other time does it have this shake. Now I can't even started it due to the kick starter problem.

Still looking for a tip. Are these four nuts on the ring nut normally present or is this abnormal?

Thanks

I believe that this was done on some bikes later in the war to correct tilt and get the clutch plates to lift squarely.

Ian is correct. It is either a REME or homemade mod to give some adjustment to any tilt in the spring. I would screw them all out to give negative contact to start with and try it like that before you put the covers back on. Ron

email (option): ronpier@talk21.com

Hello Paul,

Yes, this is what the screws are for.
In some stage it was a modification, in order to balance the clutch plates
To catch and release evenly.

Regarding what you describe with the kickstarter-
Your clutch is obviously slipping.
You are able to turn the engine over with the exhaust valve lifter because there is
Much less resistance to turn over this way.

First of all- please try to release the clutch cable from the lever on the gear.
Sometimes just a very minor pressure on it is enough for the clutch to slip.

If it would stop slipping then it is an easy fix-
Either to give the cable some slack, or to replace it, as it may have some resistance
To the pull of the lever. (Or the handlebar clutch lever is too tight)

If not-
Then maybe the gunk you cleared out of the clutch assembly was oil which
Managed to seep in.
In this case the fix would be to either was the clutch plated with a degreaser,
(I saw it being even washed with petrol and working OK)
Or to replace the plates.

Hope it helps..
Cheers,
Noam.

email (option): noam10@gmail.com

Just a thought, is it the clutch or the crankshaft shock absorber that is 'going over' ?

A clutch slipping wouldn't normally feel rough and lumpy, simply the revs go up without forward progress.

Rik makes a good point, can you look at the primary drive as you attempt to kick-over and see which part is slipping?

I've always been blessed with good single spring clutch operation, no slip, just 'care' with engaging gears... My new project is a six-spring clutch and I know I have some learning on that to come!

email (option): dickie.bobbie@hotmail.co.uk

Thank you for all the advice and discussion!

I will check today after work. New C Spanner being delivered to pull the ring nut today as is. A second set of eyes tonight will help identify if it's the crank or gearbox side of the equation.

I'll check as directed. I have a feeling it's likely oil that entered the clutch hub over winter as the bike sat. It didn't have an issue when parked last year and suddenly does it first test ride after winter. I overfilled the gearbox last year by mistake and had a major mess as oil leaked out of the bearing on the left side of the bike over many months a little as a time.

I never had the bike higher than 5mph, it was "slipping" or "shaking" at even the lowest speed while the clutch was fully engaged so I never got it up to speed. Just limped it around the block.

P.S. Good to hear that Richard. My father explained the different beast that is his 6 spring clutch when I asked him about my issues! Good luck and enjoy.

Having some fun... Thanks again all.

Long delay, got sick with sunburn so took a break for working on the bike while I healed.

Rik was correct, it was that spring. The ring gear over that shock spring worked it's way so loose that it was slipping with the small amount of force it takes to kick the engine over. I believe that was also responsible for the shaking I encountered with the clutch was released and full engine power tried to turn the gearbox over. I don't have the bike fully assembled to ride just yet but I feel as if it's corrected.

I rebuilt the clutch anyway, gave it a good cleaning and the outer metal parts a nice soak in rust remover and a nice light oiling to protect it afterwards.

For some laughs, here's how I compressed the clutch spring for re-assembly.