Chainsaw Repair

You think at 50:1 it ran hot and heat caused the piston to look like that? I don't see any wear, the first time I tore it down it was just as bad, when I got it cleaned up it looked fine, ring gap was same as when new, machine lines still on piston, maybe the cylinder an piston was a dudd, when I got it the impulse line connector was missing from the cylinder, had to rob one from another cylinder. I'll run the 32:1 don't mind at all, I don't want this to happen to my 660 or even the 029 for that matter.
Thanks
Dj