Yanmar 3JH3 & 4JH3 Series Marine Diesel Engine Service Manual PDF
The Yanmar 3JH3E and 4JH3E Series are renowned marine propulsion diesel engines widely deployed in sailboats, motor cruisers, light commercial fishing vessels, and auxiliary marine gensets. This official 284-page Workshop Service & Repair Manual (HINSHI-H8009) covers all mechanical and electrical rebuild procedures, fuel delivery calibration, and marine gearbox service for 3JH3E, 3JH3BE, 3JH3CE, 4JH3E, 4JH3BE, and 4JH3CE models.
⚙️ Yanmar 3JH3 & 4JH3 Series Factory Technical Specifications
| Engine Specification | Yanmar 3JH3E / 3JH3BE / 3JH3CE | Yanmar 4JH3E / 4JH3BE / 4JH3CE |
|---|---|---|
| Cylinder Configuration | 3-Cylinder In-line, 4-Cycle, Vertical Water-Cooled | 4-Cylinder In-line, 4-Cycle, Vertical Water-Cooled |
| Total Displacement | 1.644 Liters (100.3 cu. in.) | 2.190 Liters (133.6 cu. in.) |
| Bore x Stroke | 84.0 mm x 90.0 mm (3.31 x 3.54 in) | 84.0 mm x 100.0 mm (3.31 x 3.94 in) |
| Continuous Output Rating | 36.0 mhp (26.5 kW) @ 3650 RPM | 50.0 mhp (36.8 kW) @ 3650 RPM |
| 1-Hour Maximum Output | 40.0 mhp (29.4 kW) @ 3800 RPM | 56.0 mhp (41.2 kW) @ 3800 RPM |
| Combustion System | Direct Injection (High Efficiency Toroidal Re-entrant) | Direct Injection (High Efficiency Toroidal Re-entrant) |
| Firing Order | 1 – 2 – 3 (Front flywheel side is #1) | 1 – 3 – 4 – 2 |
| Cold Valve Clearance (Inlet & Exhaust) | 0.20 mm (0.008 in) | 0.20 mm (0.008 in) |
| Cylinder Head Bolt Torque | Stage 1: 39.2 Nm (4.0 kgf·m) Stage 2: 78.5 – 88.3 Nm (8.0 – 9.0 kgf·m) | Stage 1: 39.2 Nm (4.0 kgf·m) Stage 2: 78.5 – 88.3 Nm (8.0 – 9.0 kgf·m) |
| Connecting Rod Big-End Torque | 44.1 – 49.0 Nm (4.5 – 5.0 kgf·m) | 44.1 – 49.0 Nm (4.5 – 5.0 kgf·m) |
| Main Bearing Cap Bolt Torque | 93.1 – 98.1 Nm (9.5 – 10.0 kgf·m) | 93.1 – 98.1 Nm (9.5 – 10.0 kgf·m) |
| Fuel Injection Pump Opening Pressure | 19.6 – 20.6 MPa (200 – 210 kgf/cm² / 2,840 – 2,980 psi) | 19.6 – 20.6 MPa (200 – 210 kgf/cm² / 2,840 – 2,980 psi) |
| Cooling System Type | Fresh water cooling with heat exchanger & seawater pump | Fresh water cooling with heat exchanger & seawater pump |
🛠️ Free Diesel Engineering Calculators
Planning an engine overhaul or marine propulsion service? Use our free workshop suite to calculate torque conversions, bolt preload, displacement, and generator fuel consumption:
📑 Manual Table of Contents & Service Chapters
- Chapter 1: General Information – Engine exterior views, model designation, nameplate locations, and lifting instructions.
- Chapter 2: Basic Engine Construction – Cylinder block, cylinder head, crankshaft, pistons, connecting rods, camshaft, and valve gear overhaul.
- Chapter 3: Fuel Injection Equipment – MP2 mini-in-line pump inspection, plunger calibration, fuel injection timing marks, and injection nozzle pressure testing.
- Chapter 4: Intake & Exhaust System – Exhaust manifold, mixing elbow water injection, and turbocharger (if equipped) maintenance.
- Chapter 5: Lubrication System – Trochoid oil pump, oil filter replacement, relief valve pressure, and oil cooler maintenance.
- Chapter 6: Cooling Water System – Seawater rubber impeller pump, fresh water circulation pump, thermostat opening temperature, and zinc anode sacrificial corrosion checks.
- Chapter 7: Reduction & Reversing Gear – Marine gearboxes (KM3P4, KM4A, KBW20, KBW21, Saildrive SD40), clutch engagement, and shift cable adjustment.
- Chapter 8: Electrical System – 12V / 55A & 80A Hitachi alternators, starter motor (1.4 kW), glow plugs, instrument panel wiring schematics, and key switch circuits.
- Chapter 9: Troubleshooting Guide – Engine hard-starting, excessive smoke (black/white/blue), overheating, oil pressure drop, and uneven idling diagnosis.
Direct Workshop PDF Download
Instant access to the complete 284-page factory service manual. Clean OCR searchable PDF with full electrical schematics and torque tables.
⬇️ Download Yanmar 3JH3 & 4JH3 Manual PDF (7.43 MB)
Factory Workshop Document No. HINSHI-H8009 | Searchable & Printable
