As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SUBJECT PART APPEARS TO HAVE NOT RETAINED ITS LOWER BEARING THAT SUPPORTS THE DISTRIBUTOR GEAR. THE PART WAS FOUND TO BE BURNED AND THE BEARING HOLE MISSING THE BEARING AND ROUNDED OUT WHICH CAUSED THE MAGNETO TO FAIL AND PREVENTED ENGINE STARTUP. JUST PRIOR TO THIS, ENGINE STARTUP HAD BEEN DIFFICULT, HOWEVER, MAG DROP AND PERFORMANCE WERE NORMAL. (K)