I just about scratched a hole plum through my head trying to figure this out. My bike just kept getting slower and slower. Finnally noticed that when i twisted the throttle my choke lever would raise up and choke the engine. This resulted in some serios sputtering and a slow ride. All I had to do was remove my breather and tighten the nut on the choke lever. Seems like it's always the simple things that illude me. Now I am going to attempt to find a plug wire & install that.