Unfortunately,,,,,, Yamaha GP800R

This customer is first own of Jet ski this GP800R but only 4 or 5 ride since he bought now this motor is damaged as rear cylinder has low compression. Removed exhaust sys and cylinder head,,,,,,,
I thought just piston is damaged but piston is looks not too bad and no scratch mark around cylinder sleeve. Oh boy! I thought, Did I fuck up? but compression was too low for sure and crank shaft turn feeling is funny too.

I found piston top position is too low when TDC. This is cause of low compression.

to be continued later