Re: 1978 johnson wot rpm
I know with my 76 200 the reccomended full power operating range is from 4750-5750 rpm. In order to get the best performance from the outboard the upper end of this range, from 5250-5750 rpm, is the engine speed to use in selecting the proper prop. The rpm should be measured with your expected load in the boat. Although with the 150 it may be slightly different, hopefully someone will jump in .