Part of the Yanmar Repair Manuals.
Before you condemn a tired 1GM10 head, take a compression reading and compare it against the figure this shop manual gives: 390 to 470 psi. That is the kind of number that stalls a rebuild when you do not have it, and this book puts it in the Quick Reference Data along with tune-up specs, oil capacities, and general torque values.
The manual covers the Yanmar 1GM, 1GM10, 2GM, 2GM20, 2GM20F, 3GM, 3GM30, 3GM30F, 3HMF, 3HM35, and 3HM35F marine inboard diesels, plus the KM2A, KM2C, KM2P, KM3A, KM3P, KBW10D, and KBW10E marine gears. Its 240 pages run from troubleshooting and maintenance through full single-cylinder and multicylinder teardown chapters to the fuel injection and governor systems.
It downloads as a 64 MB English PDF. Print the torque tables and let them get dirty at the stand; the file stays clean.
Complete the set for your GM/HM Series & KM Gears
What's Inside This Yanmar GM/HM Series & KM Gears Manual
| System | Pages | Key Topics |
|---|---|---|
| Quick Reference Data | 3-7 | Tune-Up Specifications, Approximate Engine Oil Capacities, Freshwater (Closed) Cooling System Capacity, Engine Models, General Torque Specifications |
| General Information | 8-31 | Manual Organization, Notes, Cautions and Warnings, Safety First, Service Hints, Parts Replacement, Torque Specifications, Fasteners |
| Troubleshooting | 32-47 | Starting System, Charging System, Charging System Tests, Fuel System, Cooling System, Engine Exhaust Smoke, Engine Noises, Engine Troubleshooting |
| Operation, Lubrication, Maintenance and Tune-Up | 48-68 | Fuel Requirements, Preoperational Checks, Starting Checklist, Stopping the Engine, Emergency Engine Stopping, Post-Operational Checks, Engine Maintenance and Lubrication |
| Lay-Up and Fitting Out | 69-73 | Lay-Up, Cooling System Draining, Fitting Out |
| Single-Cylinder Engines | 74-104 | Diesel Engine Fundamentals, Engine Serial Number and Code, Replacement Parts, Engine Removal Precautions, Valve Cover, Breather Assembly, Decompression Mechanism, Cylinder Head |
| Multicylinder Engines | 105-143 | Engine Serial Number and Code, Replacement Parts, Engine, Valve Cover, Breather Assembly, Decompression Mechanism, Exhaust Manifold, Cylinder Head |
| Fuel Injection System | 145-149 | Fuel Tank, Fuel Valve, Fuel Feed Pump, Fuel Return Hose, Fuel Filter, Fuel Injector, High Pressure Fuel Pipe |
| Fuel Injection Timing | 150-154 | Injection Timing Shims, Plunger Roller, Fuel Injection Cam, Spill Pipe, Retainer Plate, O-Ring, Gasket |
| Fuel Injection Pump | 155-157 | Fuel Transfer Pump, Fuel Lines |
| Governor System | 158-240 | Governor Assembly, Governor Sleeve, Crankshaft |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| 2GM, 2GM20, 3GM, 3GM30, 3HM, 3HM35 | ||
| Cylinder head torque | 120 N•m (88 ft-lb) | p. 143 |
| KM2A, KM2C, KM2P, KM3A, KM3P | ||
| Transmission mounting flange torque | 20-25 N•m (15-18 ft-lb) | p. 220 |
| All Models | ||
| Fuel filter element replacement interval | every 250 hours of operation | p. 53 |
| Compression Pressure | 390-470 psi (2700-3300 kPa) | p. 68 |
| 1GM, 1GM10 | ||
| Engine Oil Capacity | 1.4 qt (1.3 L) | p. 6 |
| Battery Voltage | 12 V | p. 204 |
| 2GM20F | ||
| Freshwater Cooling System Capacity | 2.9 L (0.77 gal.) | p. 6 |
| All engines | ||
| Thermostat Opening Temperature | 108° F (42° C) | p. 188 |
| KM Series | ||
| Transmission Mounting Flange Torque | 20-25 N•m (15-18 ft-lb) | p. 220 |
| KM2A, KM2C, KM3A | ||
| Shifter Width (Standard) | 7.80-7.85 mm (0.3071-0.3091 in.) | p. 221 |
