a friend has a yz250f, his front brake disk is loose,not the bolts that hold it on, but the rivets that hold the rotor to the carrier. Its supposed to be a floating rotor, but the play is only a little, just enough to notice, the play is not only side to side, but also front to back. The bike has only 3 hours of use and everything looks allright. Is something wrong ? or is this normal.