As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MAGNETO FAILURE, ENGINE STARTED RUNNING ROUGH. PILOT COULD HEAR WHAT WAS DESCRIBED AS A RUBBING SOUND. THE MAGNETO WAS SENT BACK TO THE MANUFACTURER. INSTALLED A REPLACEMENT MAGNETO, AND IT FAILED WITH IN 1.5 HOURS. FAILED IGNITION MAG CHECK. ROUGH RUNNING. AFTER REMOVING THE MAGNETO, COULD HEAR SMALL PARTS RATTLING AROUND INSIDE.