As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ENGINE FAILED PRE-TAKEOFF MAGNETO CHECK. PILOT RAN ENGINE AT HIGH RPM AND LEANED ENGINE TO SEE IF PLUGS WERE FOULED. AFTER REDUCING POWER ON SECOND MAGNETO CHECK, MAG WAS DEAD. FOUND 3 TEETH MISSING ON DISTRIBUTOR GEAR. MAG HAS 1,045 HOURS TSMO.