My son races a 2012 KX 250F (had since new) with about 100hrs on it. Just put a Hinson clutch assembly in it about 15 hours ago so that part is good. He is starting to notice when shifting that it seems to be hitting neutrtal on him. I have talked to a few people and they have said that some of the race bikes have had a tendency of the gear teeth will get rounded off on the edge allowing to come out of gear or hard shifting. I also noticed when on stand idling the rear tire use to turn very slow now its picking up speed. I have heard that sometimes there is a collar that slides out of gear pushing up against another causing tire to turn. Any info or ideas would be appreciated.