BSA Owners' Club Workshop Discussions

The BSA Workshop => Singles => Topic started by: PaulC15 on 04 Nov, 2025, 16:53

Title: C15 lock up
Post by: PaulC15 on 04 Nov, 2025, 16:53
Has anyone come across this before? I rode my '63 C15 home yesterday and it ran perfectly. I went to start it this morning and the kickstart was almost solid. I could just about turn it over if I jumped on the lever. I thought the piston might be partially seized in the bore so I whipped the head and barrel off and it was totally free. I turned it over slowly on the kickstart (as the barrel was off), and it was fine. The bore is unmarked and the piston is fine, if in need of a decoke, but I can't find a thing wrong with it. Now I'm nervous about just reassembling it as I'm worried it might happen again miles from home. Has anyone got any bright ideas what might be going on please?
Thanks,
Rick.
 
Title: Re: C15 lock up
Post by: rhyatt on 04 Nov, 2025, 16:56
often the teeth on the kickstart quadrant don't quite mesh with the teeth on the shaft - just put into gear and rock the bike to and fro and this brings the teeth to a newer spot at which they will mesh nicely.
Title: Re: C15 lock up
Post by: PaulC15 on 04 Nov, 2025, 22:12
Ah, thinking about it that would make much more sense than a partial seizure. I'll put it back together tomorrow and ride with renewed confidence.
I'm very grateful rhyatt. Thanks for taking the time to reply.
Title: Re: C15 lock up
Post by: neil1964 on 05 Nov, 2025, 21:06
Quote from: rhyatt on 04 Nov, 2025, 16:56 often the teeth on the kickstart quadrant don't quite mesh with the teeth on the shaft - just put into gear and rock the bike to and fro and this brings the teeth to a newer spot at which they will mesh nicely.

+1 on that
Title: Re: C15 lock up
Post by: Barnsey on 08 Nov, 2025, 12:18
I note that,  on a C15 the clutch is between the kickstart and the engine.  SO, if you hold the clutch in and the kickstart still doesn't move then it isn't the engine. 
Title: Re: C15 lock up
Post by: PaulC15 on 10 Nov, 2025, 20:35
Yes Barnsey, good diagnosis. In retrospect, rushing to strip down the engine wasn't my finest hour (or more acurately a whole flippin' afternoon). Thanks.
Title: Re: C15 lock up
Post by: limeyrob on 10 Nov, 2025, 21:44
As any long time BSA owner will tell you, part of the starting ritual is to pull in the clutch and push the kick start. This frees the clutch, checks it is in neutral and sets up the engagement of the kick start gear (allegedly as my A10 can still lock up)