As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
STUCK EXHAUST VALVE IN THE OPEN POSITION HAS CAUSED THE NR 5 CYLINDER PISTON TO PUSH IT CLOSED AND BENDING THE PUSHROD IN THE PROCESS. CYL ASSY'S NR 3, 5 & 6 DID THE SAME SHORTLY AFTER. CMI WAS CONTACTED & PARTS WERE COVEREND UNDER WARRANTY. REASON THIS WAS FOUND IS CYLINDERS HOT FIRING & ENGINE RUNNING ROUGH RICH AFTER START UP. ACFT HAS ENGINE ANALYZER INSTALLED.