As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) THE PILOT ELECTED TO CARRY OUT A MAGNETO CHECK IN CRUISE FLIGHT. A 200 RPM DROP WAS THE RESULT. THE PILOT ELECTED TO RETURN TO BASE. MAINTENANCE REMOVED THE MAGNETO AND RETURNED IT TO THE MFG FOR WARRANTY. A STRIP REPORT HAS BEEN REQUESTED AND WILL BE FORWARDED ON RECEIPT.