Originally Posted by GS Addict
Allow me this one comment.
I had a similar noise on my '00 1150GS and it turned out to be the poly belt.
It had a 2" thread coming off the edge that would whack the cover depending on RPM.
I would have sworn the noise was coming from inside the engine.
Easy to check.....4 bolts
Actually I just checked the poly belt yesterday as a routine check whenever I have the cover off (to turn the engine for valve work). Smooth as a babies behind and nicely under tension, so nothing there...