I already sent the motor BACK to get fixed, but here is the plug pics, the piston and rings came all apart on the exhaust side and smashed all the pieces into the plug and the head, I mean I could hear it destroying everything, chunks of the ring stuck all in the head, The piston had some burnt oil Below the bottom ring (brownish color) , greenstreak it is interesting that u say the seal cause the gear oil was a silver or gray color the two times I drained it, would the gear oil turn that color from the premix fuel (pump gas klotz r-50) Thanks for the help I just want to find out what the hell happened....BTW this insane motor pulled the whole time till it smashed the plug to nothing, CRAZY