and to

to fix your low revs stalling please follow the link below with full instructions on how to adjust the Co levels, also try to locate the throttle screw on the left hand side of the throttle body and raise the idling speed (tickover) to between 1540 to 1550 rmp. Also adjust the chain to the recommended tension and ensure that the rubber blocks in the rear hub are not worn, otherwise order a new set from Yamaha they're only cheap. A worn set of these will cause snatchyness in your transmission and add to the stalling problems.

here is the link to adjust the co levels, and please note, this only works for XTX / XTR not the XTZ Tenere

http://www.xt660.com/showthread.php?...=Co+adjustment