This service repair manual covers the Yanmar 3JH4(B)(C)(M)E and 4JH4(F)(B)(B4)(C)(M)E engines. These marine diesel engines are renowned for their robust construction, fuel efficiency, and reliable performance, making them a preferred choice for a wide range of marine applications. Engineered for durability and ease of maintenance, these Yanmar models are designed to provide dependable power and long service life in demanding maritime environments.

This manual provides comprehensive guidance for the maintenance, repair, and troubleshooting of the specified Yanmar engines. It includes detailed procedures, technical specifications, diagnostic information, and safety precautions essential for ensuring optimal engine operation and longevity. Owners, mechanics, and technicians will find this resource invaluable for performing routine servicing, identifying and resolving issues, and understanding the intricate workings of these powerful marine propulsion systems.