BSA Owners' Club Forum

The BSA Workshop => Singles => Topic started by: RED ALEXI on 30 April, 2017, 01:52:59

Title: 69' Starfire gearbox selector forks
Post by: RED ALEXI on 30 April, 2017, 01:52:59
Hello,
 
 When stripping down my Starfire, the gearbox cluster did not stay together, but fell onto the floor. Putting it back is proving a bit of head scratcher. The selector forks are similar, BUT we're told, different. The main shaft one is meant to have a turned journal shoulder, only neither of mine do. I've put the one that is about 1/32" taller (or thicker) on the mainshaft . Is this correct ? Putting the layshaft into place and holding it there only seems to work with the kick starter quadrant in. I'm sure many of you are snorting right now, but the first time with any engine is a journey of discovery. Any tips as to how to make this painless and getting it right first time?
I haven't had this much fun since I used to try getting the two halves of an Airfix model together with all the internals balanced in one half whilst the glue went off. This obviously the design approach BSA took.
Title: Re: 69' Starfire gearbox selector forks
Post by: JulianS on 30 April, 2017, 11:45:23
The link will take you to a photo of the 1969 on mainshaft selector 57 3854 which may help.

http://www.klempfsbritishparts.com/FORK--SHIFT--250441500-0

Is your camplate marked with a "69"

The 1968 models had same selectors for layshaft and mainshaft part 40 3033
Title: Re: 69' Starfire gearbox selector forks
Post by: RED ALEXI on 30 April, 2017, 16:28:48
Thanks for the reply.

 There's a slight scuffing on the fork journal, but nothing like the turned finish. If laid fork face down on a flat surface it appears about 1/32" higher , with its camplate roller also higher than the other fork. Acccording  to Mr Ratio's book the measurements are correct for the later modified fork for the mainshaft. All correct except for it not being turned down properly. Possibly a Friday afternoon at the factory ? The selector fork shaft is stuck in the gearbox, whereas some images of rebuilds show it attached to the inner cover instead.  As for the camplate, it's stamped 'T' but I can't see any other markings. I hear BSA stopped marking some of the later plates '69' and ID can only be made by comparison. Just where exactly is the '69' mark situated ?
Title: Re: 69' Starfire gearbox selector forks
Post by: JulianS on 30 April, 2017, 18:10:52
This dimensioned factory service sheet will help identify the cam plate.

It will either have a T or a 69 stamped.
Title: Re: 69' Starfire gearbox selector forks
Post by: JulianS on 30 April, 2017, 18:13:58
These pages are from the 1969/70 manual and might assist putting it back together,
Title: Re: 69' Starfire gearbox selector forks
Post by: RED ALEXI on 30 April, 2017, 19:42:45
Thanks for all the help folks !

 I've got the 1969 BSA workshop manual, and it is very similar to the above. does the selector fork shaft detach from the gearbox easily ? It would be much easier to keep together if it was attached to the inner cover instead. Otherwise it's a bit of a push in and hope job. Tried it a couple of times and the gears weren't exactly smooth to go through, more of a turn mainshaft output and prod hard on the lever.