classic motorcycle forum

Motorcycle Discussions => British Bikes => Topic started by: jimboy on January 21, 2007, 02:47:34 AM

Title: BSA B31 Mag/dynamo
Post by: jimboy on January 21, 2007, 02:47:34 AM

I have recently bought a BSA B31 with a 1953/54 engine in a 1959 S.A frame. One problem I can't get the end cover of the mag/dynamo points cover off because the aluminium primary chain case is in the way! Is it possible to fit an alternator to this engine. Any ideas how this has happened and how I  can get around this problem.
Any feedback will be greatly appreciated.    

Title: Re: BSA B31 Mag/dynamo
Post by: LJ. on January 25, 2007, 02:12:31 AM

Hi there Jim boy! And firstly Hi to the group as I am new here, (first posting)

Concerning the points cover... My mate who parted with a similar machine (I'm wondering if it is this one!) Had exactly the same problem. He was able to purchase a repro inner chaincase from somewhere but never got round to it. There are proper inner chaincases for this problem but it is finding one. I cant remember how much the repros are but they are not cheap. It certainly can be done but I'm not sure if you are wanting to fit an alternator??

If you want to PM me then maybe I can put you in touch with my mate who had a.... or your.... B31!

Hope this helps!
LJ.

Title: Re: BSA B31 Mag/dynamo
Post by: gw6kfh on February 11, 2007, 02:17:52 AM

Hi, Just found this site, your problem is the same as the one that I had on my B33, you will find that you have the chaincase from a twin, the one that you want is b33 b31 with the cut out for the mag points cover,But the good news is that you can cut and mod the one that you have ,it is very easy to do by just marking the req amount then cutting with a small disk cutter, you should get a new piece ali welded in . mine cost me £12 for welding.Hope that this helps , all the best Brian

Title: Re: BSA B31 Mag/dynamo
Post by: jimboy on February 11, 2007, 02:27:56 AM

Thanks very much Brian.
regards jimboy