As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MAGNETO WAS SUPPLIED AS PART OF A TCM FACTORY REBUILT ENGINE. IT FAILED AND UPON INSPECTION IT WAS DISCOVERED THAT THE DISTRIBUTOR GEAR SUPPORT WAS BADLY BURNED BY SPARKS GOING FROM THE COIL TERMINAL TO GROUND ON THE M3485 BEARING CAP BY ARCING ACROSS THE SHELF OF THE SUPPORT. SUPPORT HAS A DEEP TRACK BURNED ACROSS IT.