My bikes got 15 hours on it, I took the cylinder head off and it looks like this. Is this looking good for 15 hours. Or does the cylinder have light scoring?
It does look like you have alot of piston slop. from the pics it looks like the piston is a 1mm to small. notice the gap on intake side of piston crown
I know from buying a lot of pistons that some of them do vary in overall dia. I would think it is the piston itself and not the jug.
Ive had that much play before on an all alum jug and it scored the chit out of it. Even chipped the coating.try a different piston from a different vendor. the tighter that piston fits. the less scoring and problems your gonna have