Currently there are 2 of these thiings in my shop, neither belong to me. One has barely enough compression to run, but it will start and runs about as quiet as they ever get.
The other has lots of compression, starts very easily and runs quite well if you didn't listen to the cam gear noise and the terrible knock.
The agreement was I would get them running for them, after all that's what friends are for. Maybe. When the owner heard the knock, he made a pleading look along with the question can you fix it? Now I'm stuck, what began as a nice guy favor becomes a headache. I don't like these green things to begin with.
Don't now anything about the history, but the piston slapped in the bore long enough to break it. The missing piece went through the timing gears and did considerable damage. Priced replacement parts along with a bore job and he's the one squealing!