This comprehensive Yanmar 4JH Series – 4JHE, 4JH-DTE, 4JH-HTE, 4JH-TE marine diesel engines workshop service manual provides detailed instructions for maintaining, repairing, and servicing your engine. It features high-quality illustrations, exploded diagrams, drawings, and photographs to guide you through the service and repair procedures. The manual covers a wide range of topics, including: **General information:** Exterior views, specifications, construction, performance curves, engine cross-section, dimensions, piping diagrams, and parts interchangeability. **Basic engine parts:** Cylinder block, cylinder liners, cylinder head, piston and piston pins, connecting rod, crankshaft and main bearing, camshaft and tappets, timing gear, flywheel and housing. **Fuel injection equipment:** Fuel supply system, disassembly, reassembly, and inspection of the governor, disassembly, reassembly, and inspection of the fuel injection pump, adjustment of the fuel injection pump and governor, automatic advancing timer, fuel feed pump, fuel injection nozzle, troubleshooting, fuel injection pump service data, tools, fuel filter, fuel tank (optional), and design change of fuel piping line. **Intake and exhaust system:** Intake and exhaust system, intake silencer, intake manifold, turbocharger, mixing elbow, and breather. **Lubrication system:** Lubrication system, lube oil pump, lube oil filter, oil pressure control valve, lube oil cooler, piston cooling nozzle, and rotary waste oil pump (optional). **Cooling water system:** Cooling water system, sea water pump, fresh water pump, heat exchanger, pressure cap and sub tank, thermostat, Kingston cock (optional), sea water filter (optional), and bilge pump and bilge strainer (optional). **Reduction and reversing gear:** Construction, installation, inspecting and servicing, operation and servicing, disassembly, reassembly, and special tools for both KBW 20 and 21 marine gear models and KM4A, angle drive models. **Remote control:** Remote control system, remote control installation, remote control inspection, and remote control adjustment. **Electrical system:** Electrical system, battery, starter motor, alternator, instrument panel and wiring codes, warning devices, air heater (optional), electric type stop device (optional), tachometer, and alternator 12V/80A (optional). **Disassembly and reassembly:** Disassembly and reassembly precautions, disassembly and reassembly tools, disassembly and reassembly instructions, bolt/nut tightening torque, and test running. This well-organized and easy-to-follow manual is designed for both professional mechanics and DIY enthusiasts. It provides the technical details and step-by-step instructions you need to confidently service and repair your Yanmar 4JH engine.

The Yanmar 4JH Series, encompassing the 4JHE, 4JH-DTE, 4JH-HTE, and 4JH-TE models, represents a robust and reliable line of marine diesel engines renowned for their performance and durability. These engines power a wide array of vessels, including sailboats, motor yachts, fishing boats, and commercial workboats, catering to diverse marine applications. The 4JH series boasts a displacement of 3.7 liters and employs a four-cylinder, naturally aspirated design, delivering exceptional fuel efficiency and low emissions. Yanmar's commitment to quality engineering is evident in the high-pressure fuel injection system, which ensures precise fuel delivery for optimal combustion and reduced noise levels. Further enhancing their appeal, these engines feature a compact and lightweight design, optimizing space utilization on board and minimizing weight distribution. The Yanmar 4JH series is designed for long-term reliability and ease of maintenance. The engines incorporate advanced features like a robust crankshaft, a balanced reciprocating assembly, and a durable cylinder liner for extended service life. The simplified design allows for easy access to key components, facilitating routine maintenance and repairs. The 4JH Series is also equipped with a comprehensive monitoring system that provides real-time feedback on key engine parameters, enabling proactive maintenance and troubleshooting. This combination of performance, reliability, and user-friendliness has made the Yanmar 4JH Series a popular choice for boat owners and marine professionals seeking a dependable and efficient power source for their vessels.