there's also a low speed needle for a smooth transition from low to high. very minor adjustments on this one though.....just an eighth of a turn at a time. keep trying. on mine, i turn to rich on the high at full rpm's until it gurgles a bit then back to where it runs at max rpm's then again towrds rich 1/4 turn. i hope someone else jumps in here with some tips. this seems to be an issue with the new guys. i saw a guy lift his plane nose up at full throttle and the engine raced a little bit, then he put it down and dropped the throttle again. that plane ran really well. is this standard as well?