Yep! As a kid I had a pile of those old .049 cox engines, all with melted pistons. That nitromethane burns hot!!

Chainsaws are far and away the most common engine I see to stick a piston. Sometimes it's because of wrong fuel, but I have seen it caused by some backyard "supertuner" leaning out the mixture screws.

They always say the same thing: "I don't understand, it was running better than ever, then it just quit"

Let's see. A lean fuel mixture burns hotter. Strike one.
A lean fuel mixture contains less lubricating oil. Strike two.
A lean fuel mixture causes the engine to turn more rpm. Strike three.

And a chainsaw, due to weight concerns, doesn't usually have a sleeved cylinder. They run a plated piston, so it's new cylinder, piston and rings.

It needs to be an expensive saw, or you really gotta' love it to undertake repairs of that magnitude. $$$$$$

"Forget pounds and ounces, I'm figuring displacement!"

If we accept that: MBG(+)FGSF(=)HBG(F1)
And we surmise that: BG(>)HBG(F1) while GSF(<)HBG(F1)
Would it hold true that: HBG(F1)(+)AM500(x)q.d.(=)1.5lbGRWT?
PB answer: It depends.