Flet, Without year and weight on your boat it's
hard to say what size would work best. I found that on my 95 H26 my much older Honda 9.9 hp motor will push the boat at hull speed with only 1/2 throttle. To get more amps out of the 5 amp charging system built into the Honda I had the prop repitched to raise the RPM's required to push the boat at hull speed. Now it takes 2/3 throttle to push her as fast as possible. A 15 hp should allow you to almost water ski. A 5 to 8 hp 4 stroke would push your boat plenty fast. If you need more amps to charge your battery, and if the 15 hp gives those amps at very, very low RPM, and if it is even capable of making more that 5 amps, then keep it. I had to add reinforcement onto my motor mount just for the Honda 10 hp motor. When in reverse the motor and its mount wanted to climb into the cockpit with the prop entering first. I would think that a 15 hp motor on your bracket would do the same and slice the bread in the galley at the same time. You might just be carrying useless weight for useless horsepower. Trade the 15 hp for some cash and a nice 4 stroke engine in the range of 5 to 8 hp. Recover some of the money you spend to buy the boat back. Ray S/V Speedy.
