I just got done taking off the cylinder and on just about every piston i have changed, there is a medium sized score, it looks like a faded spot. Also on the corner of the top right above the little score, there is a tiny, but noticeable little notch in the piston. These two things are both in the same spot, (if ur sitting on the bike) on the front right side of the piston. I cant see anything that it could be rubbing against, not the port openings, powervalves, etc. What do u think could be causing this????????????? thank you. They are a little to the right of the exhaust ports. oh by the way, I ride a 2003 kx100.