As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
INTAKE VALVE SEAT CAME LOOSE FROM THE SEAT BORE IN THE CYLINDER HEAD. THE LOOSE SEAT DAMAGE TO THE CYLINDER HEAD, VALVE, AND VALVE SEAT. INTERFERENCE FIT BETWEEN THE VALVE SEAT AND THE CYLINDER HEAD WAS NOT CORRECT. THIS WAS AN OVERHAULED CYLINDER. (K)