Upper rpm power can be trimmed down by turning the dolly screw inwards. These curves were all made with the Red secondary spring. The highest power was with the screw set about 1 turn inwards from flush. Turning the screw inwards another 1-2 turns held the power valve from opening as soon and made the middle power lines (yellow and red in graph). Turning inwards 4 turns from flush lowered the valve more and lowered the power to the lowest 2 curves, with a significant drop in power from 5200-7500rpm.