Pretty sure that starter was used on 15-25 HP Johnson//Evinrude outboards in the 80's. I don't know if they are still available from OMC/Bombardier but I think so.
Those are MUCH better than an outboard because they actually had a useful alternator and they don't pop out of the water in rough stuff.. They were smooth and good engines.. Used a bit more fuel than a 4 stroke would, but still not too bad.