I've ventured further into this bike and opened the primary chaincase.



And found the dreaded 6 spring clutch which shouldn't be in a 1941 bike but oh well. The spring adjusting nuts were all loose, literally spinning free. I've set them all down roughly them same and I can now kick the engine over compression (sort of) without the clutch slipping. Good. It also seems to disengage OK, a little grumble from the gearbox as I select 1st gear but I've had much worse.

I suspect those full nuts should be two half nuts so I can lock them and I've ordered some. I've also ordered a new gasket for the case. The existing gasket is stuck to the rear case - is this the way its generally done? I would have used a gasket compound (Wellseal or similar) on the cover as its easier to clean off later. You can take the cover up to the bench and work there. What do others do? Is it possible to get these oil tight but still easy to open (and close) on the road side? Currently it drips.

Last question. My parts book shows a locking washer for the cush drive nut (part 65-2521) but on the inside on the nut. How does that work? I can't see anything locking my nut - I'd have expected a fold over tab or similar. Should I worry?

Thanks
Murray

email (option): murray [at] littlewoodmansion [dott] com

Yes Murray the 6 spring clutch should have two nuts per post.

For the gasket, I glue it to the outer case and then use grease on the inner. I had my cover off a few times without renewing the gasket.

For the cush nut I use a dab of Loctite and my rattle gun.

Ron

email (option): ronpier@talk21.com

As long as you have the primary open, fit a Triumph clutch. The BSA six spring is one of the worst clutches ever.

I agree with Bruce on that.. Any 6 spring clutches I get I throw over a convenient hedge....Ian

email (option): ian@wright52.plus.com

I have the parts of a couple of 6 spring BSA clutches but have never been tempted to use them because of the destruction I have seen inside them and they just dont look right engineering wise. That chainwheel double row ballrace and the way it just seems to float around makes me shudder!!! I have four BSA bikes from the 1940s and 1950s all with M20 single spring clutches and as far as I am concerned if the parts inside these are O.K. they are great. Regards to all who have M20 or B31/33. Dave B.