My neighbors mini rev has a custom governor bypass on it and the rpms are fluctuating like its getting gas then no gas kind of like the engine is being shut down and started back up. Its wierd anyone know any fixes? I know they should probably get a "real" bypass kit but they want to know why its doing this first.

Sounds like the gov. is surging or hunting, which usually means there is not enough pressure on the spring. He prolly tied the spring back to something rather than just taking the stretch out of the spring...Look through the other posts here and you'll find the correct way to do it with a wire tie

He needs the proper bypass kit or the governor will hunt.