As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE KEEPER FOR THE MAGNETO TIMING GEAR WAS FOUND LOOSE IN THE MAG CASE. THE KEEPER, TIMING GEAR KEY WAY AND SHAFT KEY WAY SLOT WERE ALL FOUND WORN. THIS WAS A 1961 ENGINE, WITH 1876 HOURS TT. NO RECORD OF MAG MAINTENANCE COULD BE LOCATED. KEY PN 10-907-88-5.