This service manual pertains to the Hino W04C-T marine engine. It is designed to provide comprehensive information for the maintenance and repair of this specific engine model. The manual covers all aspects of the engine's operation and servicing, making it an essential resource for owners and technicians alike. This manual offers detailed instructions for engine identification, general precautions, disassembly and assembly procedures, and maintenance checklists. It also includes specific sections on the engine body, fuel system, cooling system, exhaust system, fuel filter, and electrical system, covering components such as the alternator, regulator, and wiring diagrams. Troubleshooting guides and servicing specifications, including tightening torques, are also provided to assist in diagnosing and resolving issues.