About 9.9 horsepower should make it fly. But to be certain, check the
manufacturer=B4-s rating. Less than about 20 percent of max is too
little hp. Result: Slow to plane, if it planes at all, and less than
exhilarating top speed. Performance is dragged down even lower by
passengers and Jerry jugs. My avon 3 meter does fine with 9.9.

ed
marine engine digest