As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING 500 HOUR MAGNETO INSPECTION IT WAS NOTED THE IMPULSE COUPLING ON MAGNETO WAS NOT FUNCTIONING PROPERLY. UPON REMOVAL OF IMPULSE COUPLING IT WAS NOTED THAT THE DRIVE KEY WAS NOT INSTALLED IN DRIVE SHAFT PROPERLY AND WAS PROTRUDING AND JAMMING THE PROPER OPERATION OF THE IMPULSE COUPLING. 1 PROPERLY INSTALLED, IMPULSE COUPLING OPERATION WAS NORMAL. NO DAMAGE WAS NOTED TO IMPULSE COUPLING, 469 HOURS SINCE FACTORY REBUILD.