Am I right in saying that on my Matchless G3, there should be a locking tab washer between the Burman gearbox drive sprocket and the large nut that holds it on? If so, do you know where I can get hold of them?

Yes indeed. Available from Drags, pt.no.3095-33
Possible Russells have them aswell.
Cheers, Mick.

email (option): mick@motorbikemike.org.uk

Thanks for that Mick, I'll get onto them. Cheers