Its never happened to me,but...
I bought my bike (a 99 that didnt have a limiter from the factory) from a gent who "forgot" to tell me about the boss that holds a gear in place explode on him and tear the boss in half, then he had it repaired (slob weld job). I found the repair after I had a bolt break off the fly wheel and proceeded to chew up my stator.
Instead of attempting another weld job that probably wouldnt last I decided the best course of action would be to bite the dust and replace the motor cases, I'd rather do it rite as have to waste my time and money (quite a bit by the time its finished) on a roll of the dice.
By chance you own a 98 or 99 model and havent put in a tourque limiter, do so ASAP, An idea of the cost involved...motor cases (new) $700ish (used)$300/$400, service manual $65 new, specialty tools (must have) fly wheel puller $80 the rest of the tools you can improvise becuase some run at $200 a piece, Gasket set $80/$160 (depends), labor bids ran $500 to $700 (main reason I'm gonna do it).
A lotta hassle and cash for a $170 part.
Takes the road less graveled.