As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) ENGINE TACH STARTED FLUCTUATING AND GOVERNOR BECAME INEFFECTIVE. PILOT OVERRODE GOVERNOR AND LANDED. UPON DISSASEMBLY OF MAGNETO NOTED TACH POINT CONTACT HAD BECOME DISLODGED FROM IT`S HOLDER. LOOKS LIKE THE SOLDER CONNECTION FAILED.