Cobra1 is on point as the low end feeds the high also . Set the high for max RPM and then maybe out one screw driver blade. MOve the low screw needle in screw driver blade moves, do not move it a lot a one time as a little goes a long long way.....Once the low transition well go back and double check the high as it may need one more screwdriver blade adjustment depending on u did to the low end.....