BSA Owners' Club Workshop Discussions

The BSA Workshop => Singles => Topic started by: Stubaker58 on 20 Aug, 2025, 17:34

Title: C15/B40 clutch nut lock washer
Post by: Stubaker58 on 20 Aug, 2025, 17:34
Help!

Can someone tell me how to fit the lock washer on the clutch centre nut on the unit singles?
There does not seem to be anywhere for the small tang to go to stop the washer rotating.
Also as a bonus does the spacer behind the crank sprocket sit chamfer in or chamfer out?

TIA
Title: Re: C15/B40 clutch nut lock washer
Post by: rhyatt on 20 Aug, 2025, 18:29
I think the lock tab spike goes into a hole in the side of that "tube"
I will send you PM Stu

thick washer recess outwards from sheet 422 - I can send this to you
lock washer spike goes into the hole in the clutch hub side wall
Title: Re: C15/B40 clutch nut lock washer
Post by: Stubaker58 on 20 Aug, 2025, 21:46
Thanks Richard.

So the engine sprocket spacer is chamfer in (service sheet 422).

I still can't see how the clutch centre tab washer fits. The service bulletin says "Place the thick washer with the recess outwards in position against the clutch sleeve then the tab washer which has a special tongue fitting into the clutch centre .."

My thick washer has no recess, maybe that's the problem?

Regards.
Title: Re: C15/B40 clutch nut lock washer
Post by: Stubaker58 on 21 Aug, 2025, 15:52
Right, thanks to RR I now have it all together.

My mistake was thinking that the small tongue on the tab washer hooked around the edge of the thick washer in a recess in the clutch centre that wasn't there!

Once I realised that the tongue was not to be bent over but remains flat it's obvious that it goes into the hole in the clutch centre.

Doh!!

All done up, just need a new push rod and I can finish the primary side.