My 650 has a clunking noise, my wifes 650 has a simlar noise, but not as loud. Hers is a new 07 we just bought. Mine has 2200 miles on it.
When I took a 3/8 metal rod, placeing it on the motor, and putting my ear on the rod, the noise was louder on the right hand side of the motor on the case below the rear cylinder. My first though's it was that the valve's were to loose, but its comming from the lower part. It might just be a noise they make. Don't seem to notice it when the motor is reving up
Any one know any thing about it.
Thanks
Dick

 

Have you checked the Cam Chain tension? if there is some slack in the chain it might make a slapping sound against the case. I know my 650 (DS not sure if its the same or not) makes a little noise from the case and from all the reaserch I have done it appears to be normal.

 

valves or chain would be my guess... hopefully no more!!!!!!!

 

Thinking now the noise is coming from the clutchs. They are intermittent. The cam chains tensioner is spring loaded.