What was found
ENGINE: 137 HOURS SOH (3-20-96). MODIFIED PER STC SE4985NM. NEW TCM CYLINDER ASSYS INSTALLED AT OVERHAUL AND MODIFICATION. COMP TEST: NR 1 - 55/80. NR 2 - 25/80. NR 3 - 75/80. NR 4 - 70/80. NR 5 - 75/80. NR 6 - 72/80. REMOVED ALL SIX CYLINDERS. ALL EXHAUST VALVES LOOSE IN GUIDES. VISUAL INSPECTION OF INTAKE VALVES AND SEATS SHOWED POOR SEALING OF INTAKE VALVES ALSO (POOR VALVE MACHINING BY TEM?).