The low speed needle will affect running at high speed . Mine had to be set 1/3 the way into the cat eye of spray bar and using the pinch method at idle around 2500 to 3000 rpm adjust so there is no rpm increase when pinching and then adjust high speed again and recheck idle. After adding the perry pump all my problems went away. And said, I use no nitro, this engine does not like it. Running a master airscrew 13x6 K series turning 11,900.