Hi gents....i have an older HiBird....not sure of the year but not new. It has a GY6 engine 150cc. The problem I'm having is that it wants to rolls in the direction of the gear it's in. All my other quads have a neutral so I'm not sure as to the problem. Any suggestions? What other info would you need to help me with this?

 

If the idle speed is set too high, it will do this. Assuming your idle speed is right, GY6 engines have a belt drive "variator" transmission but I have never had a GY6 to pieces so am unsure if they also have a "lawnmower" style centrifugal clutch as well. If your machine does, this must be stuck, so will require repair. If it doesn't, then the belt pulley sheaves are supposed to change speed ratios and act as a centrifugal clutch, so they must not be moving correctly. Take the ones attached to the crankshaft apart, check for faults, clean all the dust off and re-assemble. Make sure the movable sheaves, front and back, move in and out smoothly (the driven pulley sheaves are spring loaded) and that the belt is OK. There should be videos etc, showing how to take a variable belt drive system apart, on the net.