BSA Owners' Club Workshop Discussions

The BSA Workshop => Pre War => Topic started by: BEVANC on 19 Dec, 2024, 03:06

Title: 1929 500cc ohv Sloper - broken rocker box mountings
Post by: BEVANC on 19 Dec, 2024, 03:06
Hi folks,
Both of the rear mounting lugs on my 500cc S29 rocker box are fractured - see link to video clip. Does anyone know where I might be able to find a replacement, or is it likely to be possible to braize these back on ?
https://youtu.be/rlL7D6uydas?si=I5xcb5Tmfx3MLQ_M

Cheers,
 Bevan
Title: Re: 1929 500cc ohv Sloper - broken rocker box mountings
Post by: Dean Southall on 19 Dec, 2024, 07:36
Bad luck Bevan but not really bad. I good alloy welder should be able to repair them.
British Only Austria have the castings which I guess are made by a guy called Josef in Czech republic. I have had sloper parts from him and they are at least as good as the originals.
Title: Re: 1929 500cc ohv Sloper - broken rocker box mountings
Post by: BEVANC on 20 Dec, 2024, 08:01
Thanks Dean,
I may have a lead on someone who has several rocker boxes, but if that fails,s, I'll look to getting mine repaired.

Have the head, barrel and piston off today. The inner exhaust valve spring is broken, there is a lot of play in both valve guides. Amazing that despite this, the bike started 1st or 2nd kick, idled, and ran really well ! Doubt that a modern bike would be so forgiving.

Piston and barrel seem pretty good and there is no detectable play in the small or big ends,so that is a plus.

Cheers,
Bevan
Title: Re: 1929 500cc ohv Sloper - broken rocker box mountings
Post by: Mark Cook on 24 Dec, 2024, 13:32
An easy fix, the distance isn't so easy.

Mark
Title: Re: 1929 500cc ohv Sloper - broken rocker box mountings
Post by: Dean Southall on 25 Dec, 2024, 17:25
If the piston is good you have won the lottery. Lock it up safely until needed.....it took me 4 years to find one!
Title: Re: 1929 500cc ohv Sloper - broken rocker box mountings
Post by: Steve.S on 10 Jan, 2025, 17:27
Dean, You will be pleased to hear that F.W. Thornton have Sloper pistons in stock, but they don't seem to appear on their website.