I know that the timming is 28 degrees to start with and adjust from there. when I set my timming at 28 degrees it would miss atwide open so I started toadjust the timming a little at A timetill it quit missing. and I adjustedthe needles so far with anew carb I get 7000 rpm. It will not hand start so I use my starter safer on the hand will see hoe it dose in the air michael