Last winter the mag piston on my mxz 500 siezed due to the check valve jamming on that oil line. I put in a pair of wiseco pistons,the cleareance measured 4.5 thousands. Now when I looked through the spark plug hole I noticed two marks on both cylinders on the intake side. I pulled the cylinders and both pistons have scuff marks along the entire piston on the intake side only. They look very much like four corner cold siezure marks, but only on the intake side, the exhaust side is perfect. Also the scuff marks are right under the ring end gaps. Would someone know why this would happen in just under 300 miles. I want to rebuild it again, but don't want this to happen again . Thanks for helping with any advice. I also give it adeqaute warm ups, and don't drive that hard.