Part of the Yanmar Repair Manuals.
Before you loosen a single injection line, look at the publication code: 0BYMM-G00100 is Yanmar's own factory number for this service manual, and the 248 pages behind it cover the 3YM30, 3YM20 and 2YM15 marine diesels, including the C-spec 3YM30C, 3YM20C and 2YM15C, from 2005 to 2008.
Guessing on these engines has a price: a second teardown because a rod bolt went in at the wrong torque, or an injector replaced when the real fault was air in the fuel. This manual gives you the measured answer instead, covering valve lash, injection pump and governor service, seawater pump and heat exchanger work, full disassembly and reassembly, and symptom-based troubleshooting charts.
The PDF is bookmarked throughout, so the service standards and bolt torque tables you need before the head goes back on are a click away, and every page prints clean.
What's Inside This Yanmar 2YM15 / 3YM20 / 3YM30 Manual
| System | Pages | Key Topics |
|---|---|---|
| History of Revision | 3-4 | Specifications Table, Engine Outline, Piping Diagram, Seawater Pump Rotating Direction, Engine Mounting Bolt Side Pitch, No-Load Max. Speed |
| For Safety | 13-18 | Safety Labels, Service Area, Work Wear, Tools, Fastener Torque, Electrical Precautions |
| General | 19-49 | Exterior Views, Specifications, Fuel Oil, Lubricating Oil and Cooling Water, Engine Outline, Piping Diagrams |
| Inspection and Adjustment | 50-83 | Periodic Maintenance Schedule |
| Troubleshooting | 84-98 | Preparation Before Troubleshooting, Quick Reference Chart for Troubleshooting, Troubleshooting (Concerning Engine and Fuel Injection Equipment) |
| Disassembly and Reassembly | 99-138 | Disassembly and Reassembly Precautions, Disassembly and Reassembly Tools |
| Inspection and Servicing of Basic Engine Parts | 139-168 | Cylinder Block (Parts, Cleaning of Oil Holes, Color Check Procedure, Cap Plugs, Cylinder Bore Measurement) |
| Fuel Injection Equipment | 169-185 | Fuel Injection Pump/Governor, Fuel Feed Pump, Fuel Filter, Fuel Tank |
| Intake and Exhaust System | 186-188 | Intake Silencer, Intake Manifold, Rocker Arm Cover, Exhaust Manifold, Mixing Elbow, Breather System, Diaphragm Assy, Exhaust System |
| Lubrication System | 189-193 | Lube Oil Pump, Lube Oil Filter, Rotary Waste Oil Pump (Optional) |
| Cooling Water System | 194-212 | Seawater Pump, Fresh Water Pump, Heat Exchanger, Pressure Cap and Coolant Recovery Tank, Thermostat |
| Reduction and Reversing Gear | 213 | Marine Gear, Clutch, Propeller Shaft, Remote Control, Shift Lever |
| Remote Control (Optional) | 214-219 | Remote Control System, Remote Control Installation, Remote Control Inspection, Remote Control Adjustment |
| Electrical System | 220-238 | Battery, Starting Motor, Alternator Standard, 12V/60A, Alternator 12V/80A (Optional), Instrument Panel, Warning Devices |
| Service Standards | 239-245 | Engine Tuning, Engine Body, Lubricating Oil System (Trochoid Pump) |
| Tightening Torque for Bolts and Nuts | 246 | Main Bolt and Nut, Standard Bolts and Nuts (Without Lube Oil) |
| Colophon | 247 |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| Head bolt tightening torque | 53.9-57.9 N•m (5.5-5.9 kgf•m) | p. 246 |
| Rod bolt tightening torque | 22.6-27.5 N•m (2.3-2.8 kgf•m) | p. 246 |
| Fuel injection pipe joint nut tightening torque | 29.4-34.4 N•m (3.0-3.5 kgf•m) | p. 246 |
| Fuel filter replacement interval | 250 hours or whenever dirty/damaged | p. 184 |
| Fuel filter tightening torque | 20-24 N•m | p. 66 |
| Lube oil filter replacement interval | Initial 50 hours or one month operation | p. 55 |
| Lube oil filter tightening torque | 20-24 N•m (177-212 lb-in) | p. 56 |
| Seawater pump impeller replacement interval | Every 1000 hours or four years | p. 67 |
| Seawater pump cooling water leakage | less than 3 cm³/h | p. 197 |
| Thermostat valve opening temperature | 69.5-72.5°C | p. 80 |
| Thermostat full open temperature | 85°C | p. 76 |
| Fuel injection opening pressure | 12.3-13.28 MPa (125-135 kgf/cm²) | p. 73 |
