I put in a z-start in my 450 about 5 or 6 rides ago and everything was working great. I checked the gap after about an hour and everything was in spec. This weekend the bike locked up on the track after some noise from the clutch area. I took the cover off last night and found a broken tab from the outer clutch basket wedged between the case and the clutch. One of the fiber plates was broken in about 8 pieces and there was excessive wear on the fingers of the basket that was not there 5 engine hours prior to the damage. There was never any warning or loss of clutch action before the failure. Any idea what could have caused this type of problem?