The YANMAR 6LY Series marine diesel engines, specifically the 6LY2-STE, 6LY2A-STP, and 6LYA-STP models, represent robust engineering designed for demanding marine applications. These engines feature a 6-cylinder, turbocharged and intercooled configuration with a displacement of 5.8 liters (5785 cc). Known for their reliability and performance, these engines deliver power outputs of 380 hp (6LY2-STE), 400 hp (6LY2A-STP), and 370 hp (6LYA-STP), utilizing a direct injection common rail fuel system. Their advanced design ensures efficient operation and longevity, making them a preferred choice for various marine vessels. This comprehensive workshop service repair manual provides essential information for the maintenance and repair of the YANMAR 6LY Series engines. It covers a wide range of topics, including detailed step-by-step instructions with illustrations, technical specifications, troubleshooting guides, and recommended maintenance schedules, such as oil changes typically every 250 hours. The manual is designed to assist owners, mechanics, and technicians in keeping these powerful marine diesel engines in optimal condition, ensuring their continued performance and reliability.