My HR 215 has seen long hours... and over time, the compression has dropped off quite a bit. Admittedly, I had not been very faithful with changing oil... my bad. Anyway, I realize this is a broad question, but are these engines worth overhauling? Are parts available? What about an engine parts and maintenance/overhaul manual?
Yes they are its a Honda, you can get the manuals on line and you can get a new piston and rings then have the cylinder honed and put the new piston and rings in then she will be good for another 30 years.