BSA Owners' Club Workshop Discussions

The BSA Workshop => Singles => Topic started by: chaz on 17 Feb, 2020, 12:36

Title: B40 primary question
Post by: chaz on 17 Feb, 2020, 12:36
getting a bit confused, the crank turned over after being rebuilt new bearings and bushes, not free but did turn over. the gearbox works as it should but as soon as I build the clutch up (4 friction, 5 steel) the assembly wont turn over on the kick start.
Ive changed primary chain as worn, the new one from Wassels Regina was too tight but new one Reynold is slightly better .
am I over looking something? the clutch built up and set per Ruperts book.and sprocket/basket is within .020"aligned..
Title: Re: B40 primary question
Post by: berniej on 17 Feb, 2020, 13:20
Does the primary chain tighten when you try to turn it on the kickstart? That will tell you if the resistance is in the gearbox/clutch assembly or the engine....

Cheers,
Bernie
Title: Re: B40 primary question
Post by: chaz on 17 Feb, 2020, 14:19
Hi Bernie
the kick start will not turn over when the clutch is built. turns over easy with plates out. cant see th e chain tightening as no movement.
Title: Re: B40 primary question
Post by: AdrianS on 17 Feb, 2020, 16:31
Remove the primary chain. Will it turn over when the chain is disconnected?  Is the kick start mechanism jamming? Is the bike in neutral?
You need to go back to basics and find out what causes the bike not to turn over.
Title: Re: B40 primary question
Post by: chaz on 17 Feb, 2020, 17:50
a job for next weekend then, Ive had it apart a few times due to the tight chain but still back to square one again.
Title: Re: B40 primary question
Post by: Csx355 on 17 Feb, 2020, 21:45
Check the alignment of the primary chain along it's length.  If for whatever reason either the clutch centre or the crank sprocket is not located fully or you have left out a spacer the chain will bind. It's not always obvious but easily done - ask me how I know?