hi all my name is phil i have a 1993 xj600 diversion s and all was going well until I went to oulton park on sunday the engine seem to run ok but it seem as if something has come loose on the drive side of things it still runs ok no missing but it clunks going through the gears in top it sounds fine any help appreciated thanks

slack chain?

Yeah, slack chain, stretched chain, worn sprockets, loose drive sprocket, check clutch adjustment, got to be something like that