Hi sparker, yes, you can check the governor, and they are prone to crapping themselves. Firstly you need to reset the governor. With the engine switched off loosen the pinch bolt and turn the governor shaft fully clockwise with a pair of pliers, now move the governor arm to the right(so that the carby is at full throttle. remove the governor spring and start the engine, you should get nothing but idle. Move the governor arm by hand to rev up and you should feel considerable resistance back to idle, if not the governor is shot. if yes then it should be adjustable.
Cheers, Ted
