Two stroke piston melt down

DaveB

Long Jeep Fan
Location
Holladay, Utah
Well this motor is not an ATV/UTV or motorcycle engine but I wanted some opinions from those who might know what could have caused this Polaris fan cooled two stroke to do this to a piston. The piston melted badly on the exhaust port side of the piston. The other piston shows a fair amount of wear so could this happen from blow by or from running too lean ?IMGP5705.JPG
 

Gravy

Ant Anstead of Dirtbikes
Supporting Member
On the exhaust side? Too lean 100% You can see those pock mark craters on top from detonation.
The crank looks like it got mega hot too by all those rainbow 🌈 blue hues so I'd blame lack of lubrication as well.
 
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