I found a tiny three hp diesel
Sounds interesting. What is "tiny"? I'm certainly not an expert (although others here are) but I'd be really, really surprised if it was ok to use anything but diesel fuel. Depending on where you are, I wonder if diesel would be any harder to find than kerosene/lamp oil. My Vancouver, Dolphin, has a 13HP Yanmar diesel fed by a fuel tank of about 20-25 gallons -- and the main problem is the fuel getting old, tired and wet (it's not just dogs who are like their owners) because I use so little. It's never been a problem to fill the tank with a 2-gallon can that I fill at a nearby gas station that does a good business with truckers. I used air cooled diesels (mostly 2-cylinder) in English canal boats many years ago, and they're noisy! On the other hand I was looking at a small English sailboat a couple of years ago that had a single-cylinder air cooled Lister and was remarkably quiet, so who knows? The Albin Vega came new with a VP prop instead of a transmission so a search for Vega information might give you some idea of how that idea worked out. Giles Morris