This is the Vertex piston I took out of my old engine. This piston has a ton of hours of hard riding on it. I rebuilt the engine at the beginning of last year and this is what it looks like when I took it out. I measured the skirts and the bore. I ran .0025 clearance and the only wear was on the intake bridge. I opened the cylinder up to .004 clearance for this project. Motule oil!!!!!!!!!!!!!! $17 a quart but worth every cent. I was happy with the burn pattern.
dam that motule oil is some good sh*t! i opened the cylinder in my blasty after about 30 hours and the piston was all scratched up, im guessing it was that amsoil crap, no good.