I had a 1987 90 hp 2-stroke Evinrude (OMC, same as the Johnson) on my 22 Cruiser when I bought it.
When I first got it and kept it light, would run from 28-31 mph in flat water and cool air at sea level.:smile
A year or two later, moderately heavily weighted down due to my obsessive-compulsive "Be Prepared for Anything Syndrome", the max out came down to about 26-27 mph :shock:
Actually, that's not a lot of loss for all the stuff added aboard. :teeth
The OMC 90 2-stroke is as very reliable and strong engine, even if it is a bit of a smoker. 8)
Do you have a VRO (Variable Ratio Oiling) model with a separate oil tank and automatic mixing of oil and gas? :?:
I used a 3-blade aluminum prop with a 15 inch pitch with my boat. It's extremely important to keep the prop and skeg clean and smooth for maximum speed. Ditto for the hull bottom. Dings, rough edges, moss, and barnacles ='s a case of the SLOWS! :sad A lightly dinged up prop alone can subtract 2-4 mph from your top end!
Enjoy your new boat!
Joe. :teeth :thup