As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) PILOT REPORTED ENGINE OVERSPEED OF 110 PERCENT IN FLIGHT. MAGNETO WAS TESTED ON COMPONENT SHOP TEST BENCH AND FOUND TO BE MISFIRING. COMPONENT SHOP INSPECTION OF RETARD MAGNETO FOUND DISTRIBUTOR BLOCK BUSHING WAS LOOSE CAUSING DISTRIBUTOR GEAR TO WOBBLE. MAGNETO WAS REPAIRED 54.1 HRS PREVIOUS FOLLOWING AN OVERSPEED ON ANOTHER ACFT.