Britbike forum Forums British Motorcycle specific Brands Bsa bulletin board A65 Rev Counter Drive O-Ring

Hi all,

I want a new O-ring seal for the rev counter drive shaft on my 66 Lightning.

I have looked in the relevant parts books and the part number for this O-ring is 68-0588. This is the same as the two O-rings for the oil feed pipe to engine casing.

I have plenty of these O-rings but they seem too small for the rev counter drive shaft? I’ve inadvertently lost the original worn one, so I can’t measure it but it looked almost twice the size of the oil pipe union O-rings.

Can anyone point me in the right direction on this one please.

Cheers, Kev E

take the shaft to a bearing supply place ...rule of thumb with O rings is you need approx. 1/3rd of its diameter sitting over flush and some side clearance to accommodate it squeezing up ... tell them you need NITRILE rings (oil resistant)... get 10 they are cheap as at brg places