I doubt your piston is as bad as the one I posted. They make ring spacers to fill in the gap but I don’t know if you can get them that small. I suspect it is more the taper in the cylinder than worn piston ring groove. No solution there. I have a Mate that wont even run out of the water. I was 6 years old in 1952 when a friend of my grandfather took me out in his boat and let me run his 1937 Pal. When I was 11 he started let me use it through the summer’s till he passed. Everyone call it a egg beater but he never did. He would have to row over 2 miles if he wanted to fish the end of the lake until he got the motor. He never said anything but I could tell that motor was no joke to him. Tubs
A "Boathouse Repair" is one thats done without having tools or the skills to do it properly.