Just thought I'd generate some hope to people who are in a similar situation:
I lost my last bike (92 K75s) to a ruined sprag clutch. I heard it grinding on ignition for a few weeks until I figured out what it was, then it was too late. My local BMW guys explained that a repair for this would cost nearly the worth of the bike. I sold it, and then got a 95 K110rs. After a few months, I had another (what I think) sprag clutch problem. This time it didn't grind, just intermittently would not make contact (just a whirring noise with no engagement). I began to justifiably freak out, but reread the threads on sprag clutch issues. Long story short, I changed the oil and added seafoam to the crankcase as soon as possible, and I've been issue free for a few months. Literally, the problem went away. Just passing it on so that others out there don't go through the same nightmare I did.