As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT, THE RT ENG BEGAN TO RUN ROUGH, THE RT CYLINDER HEAD TEMP WAS HIGH. THE ENG WAS SHUTDOWN & FEATHERED AS A PRECAUTION. ACFT LANDED WITHOUT FURTHER INCIDENT. DETERMINED THAT THE LT MAGNETO ON THE RT ENG WAS DEFECTIVE, FURTHER DETAILS ABOUT THE MAGNETO ARE LISTED BELOW IN SECTION 5.