So I have a 1978 evinrude 25hp that I purchased about a year about, and am just now getting a chance to use. With getting to use it I am finding all the things wrong with a 40 year old motor that has obviously been neglected over the years. It will start up and run fine on the the water, but had terrible compression, about 60psi in each cylinder. To look into that issue I took the head off and found that the cylinder walls were pretty scared up vertically. I ended up taking the whole power head off to remove the pistons, and ultimately get a better look at the pistons, rings, and the entire cylinder. After looking everything other it came clear to me that it’s not something that can just be fixed with new rings and a hone. It looks like the most common replacement is .030 over sized pistons and rings. Before I dive into spending a bunch of money on parts/engine bore does anyone have any tips or info that will make the process go as good as possible? I’ve never needed to have something like this done so I really don’t know what the best way to proceed is. I’m pretty confident in the actual rebuild process, the only thing that sketches me out is bringing to a machine shop and hoping they know all the things I don’t. I live in New Mexico so I assume most places are seeming way more dirt bikes than they are outboard motors. Is it safe to assume that they are pretty universal, and I shouldn’t be worried about anything?
