Correct prop size and pitch 1984 90 HP Johnson

[Bushwacker]

The 1975 115 Evinrude I had on my Seafari for 31 years ran fine with a 13.75 dia. x 15" pitch SST prop, with motor raised so cav plate was 1" above bottom. (You'll probably want power trim if you raise it up like that.) That motor was rated at the powerhead, but it was about 90 hp at the prop like your motor, so that size prop should be about right.