As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MAGNETO EXIBITED EXCESSIVE DROP AT RUN-UP. INSPECTION REVEALED THAT THE ROTATING MAGNET SHAFT HAD DISINTEGRATED BETWEEN THE FWD BEARING AND THE ROTATING MAGNET THE 2 WERE SEPARATED COMPLETELY. THE FAILURE DID NOT APPEAR TO BE CAUSED BY STRESS. IT EXIBITED EVIDENCE OF A METALURGICAL FLAW. A PROP STRIKE DID NOT OCCUR. (K)