bsa b31 b33 gold star timing covers

[nimrod650]

hi i have 2/ b31 type timing covers one has an oil  pipe union on the casing the other is blank any information please

[chaterlea25]

Hi
Can you post a couple of photos?
The  B & M range have a breather connection towards the bottom end
I think the earlier bikes had a breather on the drive side so maybe the timing cover is blank ??
The gold star ones have a connection at the magneto end but also have a hole in which the rotary breather fits
and the rev counter drive goes on the outside
There should be numbers on the inside of the covers which may also help id them

HTH
John