As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MAGNETO FAILED - WOULD NOT RUN AT ALL. THE DISTRIBUTOR GEAR SUPPORT WAS FOUND TO BE BADLY BURNED SHOWING DEEP TRACKING FROM SPARKS GOING FROM THE SHAFT TO GROUND ON THE M3485 BEARING CAP BY ARCING ACROSS THE SUPPORT. SUPPORT HAS A DEEP TRACK BURNED ACROSS IT. DISTRIBUTOR BLOCK AND GEAR ARE COATED WITH A WHITE DEPOSIT MATERIAL WHICH IS ALSO SEEN SPATTERED INSIDE THE MAGNETO HOUSING AND ON THE COIL. MAGNETO WAS SUPPLIED AS PART OF A FACTORY REBUILT ENGINE.