I have new piston, rings, gaskets, new valves and newly cut valve seats and an OK cylinder. This is a complete top and bottom rebuild (by me) and I am curious if some minimal pitting and scoring on the cylinder would cause such low compression alone or should I be chasing something else down? Thanks! Picture is bike in question just for fun. I had it running and had some shift drum issues so decided to rebuild, compression was 100 ish previously.