My bx 25 runs full throttle at start up with the throttle lever down. Revs way up the shuts off. Throttle is not stuck. Any ideas what would cause this. Fuel shut off solenoid?
Time for the heavy hitters to respond, but as a start I somehow doubt the fuel shutoff solenoid would cause the engine to rev way up. So my bet would be it is something else.
Would probably be helpful if you give a bit more detail. Like how long does it run at high RPM before stopping? Maybe other things I can't think of but you might.
Any additional details you can give will help knowledgeable members to give advice more accurately.