What was found
DURING A SCHEDULED INSPECTION, FOUND THAT THE NR 4 CYLINDER HAD LOW COMPRESSION. INVESTIGATION FOUND THAT THE EXHAUST VALVE FACE AND EXHAUST SEAT INTERFACE SHOWED EXCESSIVE WEAR CAUSING THE EXHAUST VALVE FACE TO CUP.
As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
DURING A SCHEDULED INSPECTION, FOUND THAT THE NR 4 CYLINDER HAD LOW COMPRESSION. INVESTIGATION FOUND THAT THE EXHAUST VALVE FACE AND EXHAUST SEAT INTERFACE SHOWED EXCESSIVE WEAR CAUSING THE EXHAUST VALVE FACE TO CUP.