I have a 2003 954RR and there is this noise coming from the tranny or lower part of the motor. when idleing there is a clunk noise that happens every 5 or 10 seconds. It souds like there is something shifting around but only at idle. At 1500 rpm there is no noise. Its like when the idle is real low it bounces it around and when i pull in the clutch it goes away. People have told me ther bike does the same thing and they have tons of miles on it and its been doing it since new. My bike only has 1200 miles but the owner before me laid down the bike. The tranny shifts fine and i changed the oil and there where no shaving in it. What do you guys think!

That noise is coming from the Clutch basket. While in Nuetral the clutch basket is resonating...my CBR's all have done this. Nothin to worry about. I noticed mine while sitting outside of my friends while the bike was idling and when I pulled the lever in the "hummm" would go away and hen when I released the lever the sound returned

it might be the cam chain. i had a f3 that did the same thing. i put a manual tensioner in it from APE, no more noise.

The cam chain is located in the upper part of the motor, not the lower part. But that is another problem inherit to the 600's especially