Giles and Connie could probably weigh in
I used a 5HP Honda on an M-15, and would have preferred the 2HP if the version with a clutch had been available at the time. On the other hand, it was manageable and the main issue was lifting it on and off the mount during launch/recovery. [BTW: Umiaq's new owner wanted a smaller motor, so I still have it -- must get around to e-Baying it] The 2HP is a very different motor. Smaller, lighter and simpler. It's also noisier and vibrates more. I have one as a dinghy motor, and don't like it nearly as much as the 5HP -- but am not sure that I'd expect to actually _like_ a dinghy motor. I would not use it on an M-17 because it just doesn't seem powerful enough. These opinions are based on first hand knowledge of the M-15 (not the 17) and are worth almost as much as they cost! Giles