Britbike forum Forums British Motorcycle specific Brands Bsa bulletin board Odd BSA B33 starting issue.

I pulled my trusty 1955 B33 out of winter storage today and it fired right up, as always. Strangely though, after a couple of hours of sitting, I tried to start it and the kick lever went down without turning the engine. My first thought was that the cotter pin had sheared off, but that wasn't the case. It felt as if the clutch was slipping.

I coasted it down a hill and let the clutch out in second gear which also failed to turn the engine. After a couple of tries, though the push starting did work and I rode the bike for 45 minutes or so without issue. It also started normally after that ride, as if there had never been a problem.

I could understand it doing this if the clutch was shot, but it would just keep doing it, not get better. Any idea what's going on?

Only thing that I can contribute is "Are you SURE that the kickstart cotter pin hasn't sheared?"

I had one shear once, and both pieces stayed in place and didn't fall out. One of the pieces would occasionally catch the lever and turn it, but it wouldn't start the bike, and unless you watched carefully to see if the shaft was turning, you couldn't tell what was happening .... Thought for SURE it was a sheared clutch or quadrant, but replacing the cotter was the answer.

Just an idea ....

Lannis

Clutch or actuator mech sticking?

if the cotter sheered, you could still push start the bike. Something is sticking from sitting, I would start with the cable, and work thru the throw out mech and actuator as Nick says.

Assuming the clutch lever has some free play....

I think I would check two things for starters. Check the primary for overfilling. These bikes will wet sump and over fill the primary case causing the clutch to misbehave. It usually causes dragging but can cause slipping too.

Next, check the clutch adjustment on the right side of the gearbox to be sure the push rod has some slack.

A steel quadrant in a steel bush left standing for years is asking for rust .
Return spring could e the older thinner style which looses tension very easily
Or a new style fitted into old style covers without modification.
Another thought is the rubber stopper breaking off & dropping into the bottom of the cover .

my money would go on one of the plates getting "hung up" on some notching of the clutch basket grooves ....that could explain the intermittent nature of the failure ...only one way to find out and that is strip the plates out of the clutch and take a look at the (possibly) offending grooves ...post some pics if you can.