My son's 2000 yz250 is making a vibrating clutch noise. When in neutral and the clutch lever is pulled in, the noise subsides. Let the clutch out and a whirring, vibration can be heard/felt. I've looked at the manual and see that there is a bearing in the clutch and one on the inside of the transmission. I know I have to take it apart to determine the problem, but I was wondering if anyone has had a similar problem. I'm worried that once I get it apart, the problem may not be easily apparent. Maybe the rivets on the basket are wearing loose(does it have rivets holding the basket together)? I really hope the bearing on the inside of the transmission is not the problem, splitting cases is not one of my favorite things to do........