This manual covers the YANMAR 6N18(A)L-V marine engine, a robust diesel power unit designed for demanding maritime applications. Engineered for reliability and performance, this inline, 6-cylinder engine features a direct injection fuel system and water cooling, providing consistent power output suitable for various vessel types. Its substantial displacement and robust construction ensure it meets the rigorous requirements of marine operations. This comprehensive full service repair manual provides detailed instructions for the maintenance, repair, and troubleshooting of the YANMAR 6N18(A)L-V marine engine. It includes essential technical specifications, routine and major service procedures, and guidance on complete disassembly and reassembly. With high-quality diagrams and exploded views, this manual is an indispensable resource for owners, mechanics, and technicians to ensure the optimal performance and longevity of their marine engine.