You can't spoil a rotten egg! That being said , it wouldn't hurt to try cleaning the cylinder. Be patient, someone my come up with an answer. Don't know if muratic acid would work, but might be worth a try. Maybe contac Millium directly, they MIGHT have an answer. Had two Artic Cat cyls done by them couple yrs back, it was about $500 with new plateing, pistons, rings, brgs, gaskets. This was after major port work. That plating is mighty tough (hint-diamond hone),