GasGas Crank Endplay, Balancer

Doc,

Just wet through the same thing on my '00 XC250. Here's the deal:

The endplay is the crank slipping within the inner main bearing races. Some of the '00 bikes had a loose crank/main press fit from the factory. I noticed this early on, but ignored it, until about 1800mi (1.5 years) later when the bike started to vibrate slightly more. Upon disassembly, the crank was very loose to the point of a slight groove being worn into the surface where it was obviously turning withen the bearing race. I brought it to the dealer, who agreed it was a mfg. flaw, called GGNA who agreed replaced the entire crank for free after inspecting the original. I got the motor back together with new mains and everything is as it should be, no play.

This is a legit problem but depends on the support of your dealer. If he agrees and presses GGNA, they should replace the crank. I'm lucky to have a very supportive local dealer.

While your in there, replace the 6306 mains with M306 bearings. They are a heavy duty version of the 6306.

The balance shaft will require machining of the cases, and the part cost about $275. What I did was put the eccentric crank weight from the '01 bike in instead of my original round primary weight (about $60). This will reduce vibration slightly, but not as good as the balance shaft. Good Luck.