This service repair workshop manual covers the Yanmar 6LYA-UTE and 6LYA-STE diesel engines. These inline 6-cylinder engines feature a direct injection common rail fuel system and water-cooled indirect cooling. The 6LYA-UTE model offers approximately 440 MHP (328 kW) at 2300 RPM, while the 6LYA-STE model provides approximately 480 MHP (358 kW) at 2300 RPM. With a displacement of 6.50 L (6500 cc) and a bore of 110 mm and stroke of 120 mm, these engines are engineered for robust performance. This comprehensive manual is designed to assist owners, mechanics, and technicians in maintaining and repairing their Yanmar engines. It provides detailed information on general engine specifications, inspection and servicing of basic engine parts, fuel injection equipment, intake and exhaust systems, lubrication, cooling, and the reduction and reversing gear. The manual also includes sections on the electrical system, disassembly and reassembly procedures, and troubleshooting guidance, supported by step-by-step instructions, diagrams, illustrations, wiring schematics, and essential specifications.