I had a 7.5 hp Honda 4 stroke as the auxiliary on a 25'' MacGregor. It pushed us along at hull speed at less than full throttle and never faltered in ocean service off the south shore of Long Island. The built-in alternator kept the battery fully charged.
It seemed to me that it ran quieter than similar sized 2 strokes. Not having to mix oil into the gas just about eliminates the
exhaust smoke and odor. Using ordinary automotive motor oil saves money over the pricier 2 stroke oil.
I loved it.
If you want a 2 stroke kicker, better hurry -- they are scheduled for phase out for environmental reasons.