What was found
ONE CYLINDER WAS REMOVED FOR LOW COMPRESSION. INSPECTION REVEALED THE EXHAUST VALVE BADLY WORN IN THE VALVE KEEPER AREA. STEM DIAMETER WAS WORN FROM .336 INCH TO ,280 INCH. THE OTHER 3 CYLINDERS WERE INSPECTED AND FOUND TO HAVE WORN VALVES AS WELL. NO SIGNS OF IMPROPER ASSEMBLY WERE FOUND. THE VALVE HAS BEEN RETURNED TO AIRCRAFT TECHNOLOGY CORP. FOR ANALYSIS. SUSPECT THE VALVES MAY NOT HAVE BEEN PROPERLY HARDENED.