I've had the chain eat through the cover once. Welded the hole in the cover and new chain kit.

110k miles later I had the chain skip a tooth. Second gear doughnuts out at Mudfest. <img src="/forums/images/graemlins/smile.gif" alt="" />
Guide had broken ~3months eariler and I didn't replace it right away. Chain must have had some streach to it and the motor shut down once it had skipped.

Fur clog in the sausage grinder