As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) AT THE 200 HRS INSPECTION OF THE AIRCRAFT, AT ENGINE CYLINDER COMPRESSION TEST, MFG SB M91-6, AND THE TEST FAILED FOR CYLINDER NR 4 DUE TO LEAK FOUND BETWEEN FINS AT CYLINDER HEAD. THE CYLINDER REPLACED AND AIRCRAFT RETURN TO SERVICE AFTER THE INSPECTION.