Killed my tbolt 141cc Bore kit

[Big Bird]

Originally Posted by TxTaoRider

In the pic of the gasket, it looks shiny or different right in that area. And since the motor pulls in air and compresses it, it could suk in a little air there as well as push it out.

Possible right from the timing chain area which would make it not visible from the outside.

[Big Bird]

I think you nailed it. That's right where the ring groove is pinching the ring too.

[grumpyunk]

Given the piston crown is not bare and has some carbon deposit, as does the cylinder head, I doubt you were running lean. I think you have a manufacturer defect in the alloy used when casting the piston. Yes it got hot, but there is no evidence in the image of any heat related melting. Most pistons do not distort under use. This one got hot enough to distort, but not hot enough to do any 'melt' damage. The fact that it is on the intake side is more evidence of poor alloy being used. The temperature would be slightly less as you have the 'cool' side of the cylinder head contacting the cylinder wall, vs the exhaust side, where hot gases are heating the head, and that's having some heat conduction down to the cylinder wall.
Wish the images were larger and the above two were lit a bit brighter.
tom