I posted a short version of this on the Facebook group and didn't get much response, hoping someone here can help.
Teaching a school on the track a few weeks ago going at a moderate pace, I started to feel a bad vibration, finished the lap at a slow pace and pulled off. Checked tire balance, wheels, rotors, cush, wheel bearings, etc. and all checked out. Went back out and immediately felt it again. I finally had some time to look further into it this week. I removed the clutch and everything looks very good. I removed the stator cover and found the bolt pictured below sitting in the bottom of the cover under the stator coil. It is not from the cover, the bolts that hold the coil, cps, and wiring are all still in place in the cover and I can see no holes where this might go.
Figuring it may have come from somewhere else in the engine I removed the valve cover and oil pan to inspect. Again, I found nothing from the things that I can see.
The engine starts fine and runs fine and doesn't make any strange noises. I can't really feel the vibration until I'm really moving. The loose bolt that was floating around looks like it got very hot at some point (rolling in stator, likely) and the threads are kind of flattened.
Do you know what else might cause a vibration, and do you recognize this bolt and maybe where it came from? I have considered that the two may be completely unrelated but that doesn't really get me anywhere else at the moment. Nothing else in the bike seems off at all. It shifts fine, clutch function, it revs like normal, brakes like normal, etc.
Of course I am supposed to race this thing next weekend, which is looking unlikely. I am very hesitant to just put it back together without finding the source of this bolt.