This manual covers the Yanmar JH4 series of marine diesel engines, specifically models 3JH4E, 4JH4AE, 4JH4-TE, and 4JH4-HTE. These engines are designed for reliable and efficient operation in marine applications, offering robust performance and durability. Their engineering reflects a commitment to quality and longevity, making them a trusted choice for vessel owners and operators seeking dependable power.

The purpose of this manual is to provide comprehensive guidance on the required maintenance procedures for your Yanmar JH4 series engine. It includes detailed illustrations, schematic electrical diagrams, oil and water flow diagrams, and sensor and switch locations. This resource is essential for ensuring the optimal performance, longevity, and safe operation of your vessel's engine, serving as a critical reference for owners and technicians alike.