I have a good running JMS saw. Many were good running.
But they ain't gonna run good, or at all, for a long time with the shortcuts and the crap he pulled.
The first saw I got back from him had a totally rubbed piston, a muffler held to the jug with one bolt (yeah one) with the exhaust manifold drooped into and across the ex port. Then the muffler, both muff to case bolts stripped completely and one bolt missing. The top bolts, one totally stripped.
I was told:
You ran it lean, how did you mess the piston up that fast? What mix you using?
Answer:
I noticed I was missing a bolt and you told me the muffler needed another deflector welded on it. So to answer your question, I didn't run it at all.
Then...
You can't get it all out of the case. I bet if you run it some more, the piston will clean itself up. Just put larger sized two lower bolts in the bottom of the muffler. No need to tap. Guys do it all the time. Don't weld or retap the stripped upper nut, Just add a jam nut behind it.
This saw was my payment for approximately $1200 of good and services given to him. He offered me a new piston, but At the time, he was "maxing out" 066 jugs and told me he found a "unicorn". So I sent the saw back for "the treatment" and built his dad a minty 026 PrO in exchange for the new jug swap and porting. I had been keeping this lil beauty for my self.
The "Unicorn" had its share of problems, including the standard rubbed piston. But when I got it back, a good friend got his saw and it was a non-running POS that J had just done. Evidence was just coming out that J was a sham at that time. I felt lucky at the time, at least I got lube. My friend got it wrapped with coarse sandpaper and inserted deeply. This beauty took something like 20+ timeserts to make the stripped holes go away.
The stories of deception will just keep piling up. There will always be some excuse. There's something seriously wrong with the guy.