Early BSA ULTRA exhaust valve dimensions

[johnnyv]

Hi gang anyone got an early BSA exhaust valve lying around you could take dimensions of?
Looking online the whole valve assembly looks very similar to the Webley ones of the era and am curious about the valve and stem dimensions. Ultra, Scorpion R10

Trying to revive an older Webley Raider 2 shot which is leaking persistently through the exhaust valve area and wonder if the stems are nigh on regards measurements.
Long shot but back in the day they were produced only a few miles apart so wonder if there was any common bits and bobs between them if any work was outsourced etc

 

[rkr]

3.2mm stem, early poppets were slightly larger than current ones. Search Knibbs site for exact poppet diameters.

 

[johnnyv]

Cool cheers for that hmm not too far off the Webley stem. Cheers buddy will have a squint at the site