With someone holding your airplane and after your engine is warmed up, take it to full throttle and pinch your fuel line to the carb just for a second and listen. If she speeds up your rich, if it hesitates your lean. Start out with your high speed needle at 1 & 1/2 turns out, if its rich turn in just a few clicks, if its lean turn out just a few clicks. After the high speed needle is set, have someone hold the airplane and you advance the throttle to full and listen to the engine, tilt the nose up slightly as to similate take off if the engine does not hesitate then you are set. Make sure you have padding around your fuel tank and that you do not have bubbles inside your fuel tank.