This workshop service repair manual provides comprehensive information for the YANMAR 6LY3 Series marine diesel engines. These engines are known for their robust construction, reliability, and performance, making them a popular choice for various marine applications. Featuring a 6-cylinder configuration with a displacement of 5.8 liters, these turbocharged and intercooled engines deliver substantial power output suitable for demanding operational requirements. Their advanced engineering ensures efficient fuel consumption and compliance with emission standards such as EPA Tier 3 and IMO Tier II, reflecting a commitment to both performance and environmental responsibility. This manual serves as an essential resource for owners, technicians, and mechanics involved in the maintenance and repair of the YANMAR 6LY3 Series engines. It covers a wide range of critical topics, including detailed maintenance procedures, troubleshooting guides, technical specifications, and important safety precautions. By providing clear instructions and essential data, this manual empowers users to perform routine servicing, diagnose issues effectively, and ensure the optimal performance and longevity of their marine propulsion systems.