As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT MAGNETO WAS REPORTED INOPERATIVE. FOUND APPROXIMATELY ONE-THIRD OF THE LEFT DISTRIBUTION GEAR TEETH MISSING. BROKEN TEETH WERE SCATTERED THROUGHOUT THE MAGNETO. COULD HAVE DAMAGED THE RT PORTION OF THE MAGNETO. CAUSE IS UNKNOWN. NO GEAR HOLDING DEVICE HAD BEEN USED SINCE MAG WAS PLACED IN SERVICE. SUBMITTER SUGGESTS THIS IS AN INHERENT DESIGN PROBLEM.