My 71 9.5HP twist grip started giving me problems today. the black grip over a white piece of plastic just spins without really affecting the RPM's. if I twist on the white part the throttle responds normally but keeps turning was past where it used to stop in both directions. the only way I can get it to work perfectly is by tightening the idle screw on the side in to the desired speed. What should I check since the grip doesnt simply just pull off?
