I know nothing about electrics - but Props I know my share. What size prop are you using? there are some quite small 1/4" props - there are also propshafts with a 3/16" stub shaft and 1/4" flex that will open the door to all the 3/16" props.

Could certainly reduce the blade area on a prop you have (de-tongue it some) which will free up the motor. I have done so on gassers to get a prop to hit the right RPM.