As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MADE A PRECAUTIONARY LANDING ENROUTE, DUE TO THE ENGINE INTERMITTENTLY LOSING POWER. INVESTIGATION DETERMINED THAT THE RT MAGNETO WAS ROUGH AND BARELY OPERATIONAL. REPLACED THE MAG WITH AN NEW 4390. ON OPENING THE BAD MAG, FOUND THE POINTER ON THE DISTRIBUTER GEAR HAD COME LOOSE AND FELL OUT WHEN TAKEN APART. ENGINE HAS 23100 HRS, WO 1405-8-26-10. THE MAG WAS NEW A THAT TIME.