HOIST,
Sorry to hear of your troubles. I had this same issue last aug with my SERK. Although, no damage to the starter or jack shaft. The ring gear had two teeth broke off. And by the way, since the starter was "ok" they would not warranty it foe the chrome upgrade, but it ended up not being an issue since they were on back order at the time, anyway. I just hope that all the readers take notice of this problem and get their scoots in at first notice of grinding. And not to mention the problems with the fly wheel, mine was off 56 thousands, I have an appointment for the 1000 mile service in the a.m. since the complete engine replacement.
SOKOOL