Originally Posted by RedRupert
OC, that piston skirt looks a bit bright - is it worn? Have you a better photo?
No, no wear. It was very clean and no sign of problems at 36,000 miles. The nikasil looked great, but the shop owner did give the cylinders one twist of a honing stone. I suggested against it, but he said he has done that to hundreds of KTM engines, and it works as long as you only do it very, very lightly. That's probably what you are seeing. Beyond that, it's just the lighting (and my poor photo editing).