As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) AFTER COMPLETING THE ENGINE CYLINDER DIFFERENTIAL COMPRESSION TEST ON A ROUTINE INSPECTION, DETERMINED NR 3 AND NR 4 CYLINDERS HAD EXCESSIVE LEAKAGE THROUGH THE EXHAUST VALVES. THE BAFFLES AT EACH END OF THE EXHAUST MUFFLER WERE FOUND BROKEN AWAY FROM THE ORIGINAL LOCATION AND JAMMED NEAR THE OUTLET PORT. EXCESSIVE EXHAUST BACK PRESSURE COULD HAVE CAUSED THE EXHAUST VALVES TO DETERIORATE PREMATURELY. (X)