This Service Repair Manual covers the YANMAR 6LY(M)-UTE and 6LY(M)-STE marine diesel engines. These turbocharged, intercooled, 6-cylinder engines feature a displacement of 12.917 liters and deliver approximately 405 mhp at 2200 rpm. Designed for marine applications, they incorporate direct injection, common rail fuel systems, and electronic governors, offering robust performance and reliability. Cooling systems are available in raw water or keel-cooled variants, and various marine gearbox options can be paired with these engines.

This manual provides comprehensive guidance for the maintenance, repair, and technical understanding of the YANMAR 6LY(M)-UTE and 6LY(M)-STE engines. It details essential procedures, including lubrication specifications, oil and filter change intervals, and electrical system information. Technical specifications, troubleshooting advice, and safety guidelines are included to assist owners, mechanics, and technicians in ensuring optimal engine performance and longevity.