This workshop repair manual covers the YANMAR 4LH Series Marine Diesel Engines. Designed for marine propulsion, these internal combustion engines are engineered for reliability and performance in demanding maritime environments. The YANMAR 4LH Series represents a commitment to robust construction and efficient operation, ensuring dependable power for a wide range of marine applications. This comprehensive English-language manual provides detailed guidance for the maintenance, servicing, and repair of all YANMAR 4LH Series models. It includes step-by-step repair procedures, routine maintenance schedules, troubleshooting information, and essential technical specifications, supplemented by clear pictures and wiring diagrams. This resource is designed to assist owners, mechanics, and technicians in effectively maintaining and repairing their YANMAR marine diesel engines.