As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE FLIGHT, ENGINE LOST PARTIAL POWER. PILOT TURNED AROUND TO RETURNED, COULD NOT MAINTAIN ALTITUDE, AND LANDED. DURING TAXIING THE ENGINE DIED. PILOT NEVER TRIED TO RESTART ENGINE AND THE AIRCRAFT WAS TOWED. NO VISIBLE DAMAGE TO THE AIRCRAFT. INVESTIGATION FOUND THE NR 8 CYLINDER EXHAUST VALVE PUSHROD BROKEN AT ROCKER ARM END. THE PUSHROD WAS REPLACED AND THE ENGINE IS RUNNING GOOD.