• 26 Answers SOURCE: I work on these every day. Its either gonna be the rotor or stater, the voltage regulator, but most likely its a bad stepper motor which is the throttle motor, or control board. Thats all that could be causing that so its one of those.
If its the rotor or stater thats bad it causes the generator to RPM up because it thinks its not producing enough power due to that. I had the same problem with the same one we just fixed and it was the slip rings on the end of the rotor so bad rotor. Posted on Jul 09, 2009.