You can get a helper to adjust the carb while you are cutting and get max power. You should have a tachometer to do this right. The other way is to gently turn the high speed adjustment in (cw) until it stops, then 1 1/4 turns (ccw) to richen until the rpms start to drop. Everyone who uses gasoline powered equipment to make a living should own a good tachometer. My preference is the tach sold by Stihl & Echo because it has a clip-on lead and a large screen.