I have a 1994 FX1 it has the 701CC engine with a aftermarket Factory pipe. when it gets warm from riding hard it will sudenly not rev. it sound lie its only running on on one cylinder. it will idle but it will not rev it kind of misses when you punch it. it seems like it has some sort of overheat sensor. when it cools off it runs fine again. if I ride it kind of mello it does not cut out. any sugestions? the pipe is getting water I have it where the pipe runs a little hot for more power in with wide open throttle.