The position of the diaphragm is controlled by the throttle position AND the engines ability to pump air.( LESS at high altitudes) IF you load the engine and thereby reduce the revs it will be very limited in the POWER it can produce. Look at any Torque, RPM and HP chart produced on a dynamometer. There will be a MAX torque RPM and well above it a max SHP RPM as well as a never exceed RPM. Nev