Originally Posted by Truckracer

Capt'n, that shiny bore syndrome was common early on with the Chinese engines but I bet you don't see that much if at all any more ... at least on the better Chinese engines. Their quality has come a long way in a very short time. Regardless, as av8tor said, a bit of very fine grit sandpaper is not going to cut through any plating, even cheap plating. We're not talking a 18 grit grinder disk here!