As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) THE AIRCRAFT RAN ROUGH ON L/H MAGNETO (APPROXIMATELY 200 RPM MAGNETO DROP). LT MAG WAS REMOVED AND FOUND TO HAVE 8-10 TEETH MISSING FROM GEAR (NYLON) WHEN VIEWED THROUGH TIMING WINDOW. MAG WAS REPLACED AND THE AIRCRAFT RETURNED TO SERVICE.