I've been experiencing some problems with a 2006 600RR. I have this rattle like noise that appeared out of nowhere, and at first I thought it was the CCT, I replaced it with an APE, changed the cam chain and the guides, but the noise is still there. Today with a relatively cold engine, I revved the bike to 3k RPM and managed to trace the noise to the clutch.
The noise happens regardless if the engine is cold or hot, however the noise is hard to hear if I drive the bike below 50C Temps, once it gets to about 75C or higher, it's really noticeable under load starting at 4000 rpm. It was really easy to mistake it for a worn CCT. I do not touch the bike until the temps are showing 40C, but if I had, I would have noticed that the noise is actually very loud at the clutch cover, in neutral. Sometimes when it's hot outside and bike is also hot, this noise gets so loud to the point of overpowering the engine and exhaust noise.
Everything seems tight on the clutch side, very little to no play on the basket, no slippage. The noise happens regardless if the clutch is pulled in or not in gear or neutral, however the only things that turn while in gear with the clutch pulled in are the crankshaft and it's components, clutch basket, starter clutch. Could this be caused by the starter clutch? I have about 1000 km with this annoying noise, I would assume that if it was a spun bearing whatsoever it wouldn't have last this long. I do not have any good mechanics around my area so I would really appreciate some insight on this.
-bike has 39000Km
-fresh oil (10w50), did the same noise with 10w40
-valve clearences are within spec
-no idea when the clutch was serviced or if it was at all