As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING ROUTINE INSPECTION WHILE CHANGING THE ENGINE OIL, WE FOUND A SMALL PIECE OF COTTER PIN ON THE OIL DRAIN PLUG MAGNET. BOTH MAGNETO WERE REMOVED AND THE PIECE WAS CONFIRMED COMING FROM THE MAG GEAR NUT. 2 NEW COTTER PIN, PN M2556 WERE INSTALLED IAW SB 03-7 AND ACFT WAS RETURNED TO SERVICE. WE WERE UNABLE TO DETERMINE THE PN OF THE BROKEN, PIN DUE TO THE CONDITION.