Hi. I bought a pair of chinese 125 quads for my kids for Christmas. One runs great but I thought we burndt the clutch on the other. It acts like Neutral no matter what. I've been waiting to hear about warranty clutch replacement when I notice metal shavings around the front sprocket (pulled the cover). It also looks like shaft lurches around in the sprocket a little bit. Could we have killed that shaft? If so, any idea how to replace it?