I was out having a good ride when the bike started to vibrate quite bad. It was worse at high revs. Could feel it through the bars really bad. So I took the clutch cover off and the springs, and found the big nut had come loose. No doubt because I didnt have a clutch holding tool when I was last mucking around with it. Anyway I tightened it all up again and the vibration was gone. Ripper I thought, but now its back after another good ride. I checked out the clutch again and the nut was still tight. I took the basket off again and checked it all out, put it back on again, started it up and BBBZZZZZZ. The vibration still there. I looked at the cams and they look fine ? A few shavings in the oil filter, looks normal to me( there is always some crap in there). I was thinking maybe riding it with the loose clutch has now wrecked the brass bearings on the primary drive gear ?? There is only the slightest bit of movement if you try to wobble the clutch assembly when its on the bike all bolted up ?? Any ideas ??