Thanks for the "every noob must read" post. Standard 66cc Chinagirl: I am in the process of upgrading the cylinder, intake and exhaust posts with the higher grade steel. So, it's time for me to remove the carbon build-up on the top of the piston, the inner top cover, and the very top of the cylinder itself. I have, in the past, used the wire brush on my grinder to remove these deposits from the piston & top cover, but I'm at a loss of how to remove it from the very top of the cylinder chamber without messing with the smooth inner cylinder surface. I would welcome any details on how to do this properly.