Yeah it does look like a 2 stroke seizure. There's probably around 300 miles on this rebuild/bore. There was plenty of oil everywhere and no stuck rings.
The only thing I can think of is the pistons themselves although the clutch side piston looks like new. When I sourced the parts off ebay, the ad stated that the pistons were OEM but when they arrived, they were in boxes labeled SK. SK's are aftermarket. The OEM rings were sourced from a different seller and came in OEM boxes. I noticed that the wrist pins were a little more snug than the ones in the original pistons so I am wondering if that may be another contributor although the wrist pins seemed fine.
Water under the bridge now. Cleaned out the lower cases, tranny, clutch and other misc parts. Will button up everything tomorrow and wait for the new top end parts.
I really needed to take the engine out of the bike anyway to repair the small nick in the paint on the top engine case in the back where the starter cable comes up into the airbox area. That little nick was really bothering me.
