I had a problem with a je piston, It cracked across the top and put a hole in the center. Iwas really pissed and called je. They told me to send it back so they could look at it. Brian at je called me back and told me that it was caused by overheating (denotation), the bike needed to be rejetted. Then he tells me he's going to send me a new piston. I almost dropped the phone. Funny! He also told me they increased the length of the wrist pin to help solve the problem. To me the problem they had was the piston was flexing. Anybody out there that has problems with je, call them you never know?

 

Exact same story here (talked to the same guy and everything) with raptor03s piston. His was not running lean but possibly to low of octane. I think there's other problems tho, and I don't meen with his engine or set up.