As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT ENGINE TT 378.8 HOURS, REMOVED ALL CYLINDERS AND HONED DUE TO 'GLAZING'. AT ENGINE TT 380.0 HRS, PILOT REPORTED ENGINE RUNNING ROUGH. REPLACED NR 6 CYLINDER ASSY DUE TO 'LOW' COMPRESSION 20/80 PSI. FURTHER INSPECTION OF CYLINDER REVEALED EXCESSIVELY WORN INTAKE VALVE AND SEAT. CSB9811B C/W AND SUBMITTED 8-7-98 AT ENGINE TT 285.6 HRS.