Does anyone know if the Harley Davidson type unvented bayonet gas caps are the same size as the oil filler caps on the slant 4? (I'm presuming that BL used some sort of standard part from somewhere rather than having them specially made?)
Looks similar, but hoping someone else has had the same thought and tried this?
http://www.ebay.co.uk/itm/NEW-HARLEY-BO ... 19f3499ee8