As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ENGINE EXPERIENCED INTERMITTENT MISS. WHILE TROUBLESHOOTING, DISCOVERED NR 4 CYLINDER ROCKER TO VALVE CLEARANCE COULD NOT BE SET PROPERLY. ENGINE TORN DOWN AND FOUND TWO TAPPETS DEFECTIVE. SOCKET END WAS LOOSE AND TURNED FREELY IN END OF BODY. CAUSED EXCESSIVE WEAR ON SOCKET TO THE POINT THAT VALVE ADJUSTMENT NOT ATTAINABLE. TWO OF THE EIGHT HAD THIS CONDITION. BOTH ON NR 4 CYLINDER.