k6 engine knock

[Maj]

This is also a known problem with the clutch basket on the busas not having strong enough rivets. My K4 also has it and when I spoke to the local motorcycle shop in regards to it, they said that they could put in a new clutch, but it would probably happen again at a later date. Mine usually goes away with the clutch in though.

First time i have heard of this ???
seen and heard of the studs on the btl that support the clutch springs coming loose many times,
btl itself can rattle a little esp if the cyls need a balance and the idle is not quite smooth.
also doubt bad cranks or bearings as it would become very noticable very quickly, however a quick way to tell is drain the oil and look for copper, only place in the engine that has copper is the bearings,
anything else that shows in the oil may be a clue to the problem