Hi all,
I have a 1939 BSA B21 De Luxe 250cc that is new to me.
Kick start spring is broken and I have a replacement.
I followed the manual I have as best I could, getting to this point in the photo, but I can't get the inner case apart.
I have tried gently chapping it off from the left side but no movement.
I have kept the gearshift mechanism in place as the manual suggests and the screws holding this inner case are removed.
A friend who ran Bantams suggests applying some heat and continue chapping from the other side.
Is this correct, or is there a trick I am missing?
Thanks in advance for any help.
You need to remove the gear change mechanism, especially that nut on the end of the selector shaft. That actually looks like a later M20 gearbox. I have the work sheets for the M20 box, which ought to be studied before assembling. Ron
Thanks, when I get to the workshop I'll try with that nut off.
Let me know if you want a copy of the M20 service sheets
Got the case apart. There was a third bolt hiding behind the linkage!
militaryron, yes please, if you could share the service sheets that would be a great help, thanks.
Can you attach them to a message or do you need me to send you my email address?
regards, Steve
I sent a PM with my email address. Ron
Funny enough I've just had to replace my kick starter return spring.
I found it quite tricky getting the 1/2 turn of pre-load on re-assembly. It needed a suitable tool for the screw driver slot and another pair of hands. We managed to use a bit of plate and some Molegrips. If I have to do it again I'll make a proper tool from bar material with a suitable "blade" on the end with a centering spigot and a hole for a Tommy Bar at the other end.
It seems to me that the design of the spring/quadrant gear is very poor; the coils get displaced as it rotates as the tang/end of the spring is only partially retained in/against the quadrant gear and the part of the spring that actually takes the load bears on a sharp corner on the gear. The broken spring shows extensive wear on numerous coils. I wonder were all that metal went? Oh, I know, in the gear box. Still it's a bit late to query the manufacturer I suppose!
Alan