I was out riding new years eve and the bike seemed to be running fine. When all of the sudden on my last lap of the day the motor started making this clanking noise like something let loose inside the motor so I killed the motor and rolled of the track. When I got home I tore the top end down and I could see where the skirt on the front side of the piston had come in contact with the cylinder wall there was some slighty scoring on the cylinder wall. I checked the rod and there is a very small amount of up and down movement. My guess is that the rod bearing on the crank needs to be replaced or maybe I just need a new piston and to have the cylinder repaired. What do you guys think? what a sucky way to start off the New Year?