One Thursday, while practicing on Glen Helen’s USGP track, the bike started to stall with increasing frequency. Then the top end started to clatter at high rpm, similar to what you’d hear when the valves need adjusting. And then it made a really bad noise. Worried what that might be, I parked it. A subsequent autopsy revealed that the left-side exhaust cam was badly galled, legacy of a clogged oil jet—this despite routine oil-and-filter changes. Even worse, it had spit a shim, which worked its way down to the bottom end, requiring the cases to be split.