i went to the track saturday with my turmoil and ran for a couple of hours with my cousin and his 8ight. had some fun. let my cousin drive and he jumped it full speed and landed and ran into a stake. bent the muffler but i managed to bend it back and continued to run it. later i came in to get fuel and found out that my air filter had fallen off, no telling how long it was off for. so i took of the heat sink to check it out and there is a scratch on the top of the piston head. im gonna polish it up and see if i can smooth it all out. i also managed to lose a heat sink screw(before i decided to take of the heat sink) and burnt 2 glow plugs.

If the scratch is on top of the head leave it alone just clean out your engine really good relube and put it back together. A piston wall scratch would be bad but not the top and if you remove any metal from the top of the piston you will take away from the compression.

usually a little scratch in the top of the piston wont hurt anything, its the scoring on the sides that you need to watch for. I would suggest taking the engine apart and checking for any damage and cleaning it out for precautionary measures.