Here's What I'd Watch For
Sergio:Although Honda makes the best gas engines in the world, this is not a marinized engine. Salt water corrosion, will be a consideration. Air cooling will be necessary, so you can't just box it in without adding air blowers. Exhaust fumes! How will you remove these? Vibration! How will you dampen the engine base so that your prop shaft doesn't vibrate? Noise! Although Honda makes very quiet gas engines it may be noisy down below. Justin mentioned weight. Although your placement will allow the weight to be low, thats good, but where will you place the gas tank, or maybe its integral to the engine, which is bad because its deep in the boat and we know all about gas vapour in bilges. You will have to add bilge blowers. What about the shaft engine interface coupling? Will it take a shaft coupling? What about remote controls for this engine? Do you have to go below to start it, and shut it off? The cost of the engine, shaft, cutlass, bearing, stuffing box, prop, remote controls, seperate tank, engine beds, etc. is difficult to justify on a boat only worth 5K (a guess), never mind the tinkering necessary to get it to work. I commend your dream, but the reality of such an undertaking may prove formidable.Don