Part of the Yanmar Operator Manuals.
Set the injection timing on a GM series without the factory figure and you are guessing. Yanmar's own operation manual puts it in plain numbers: 15 degrees before top dead center on the single and twin cylinder engines, 18 degrees on the three cylinder models, with injection pressure, compression ratio, and bore and stroke on the same Specifications pages.
Publication 49961-202281 covers the 1GM10, 2GM20, and 3GM30 along with the F, V, and FV variants, in direct sea water and fresh water cooled forms. The English section runs from installation and break-in through daily operation, periodic maintenance, and long-term storage, then into troubleshooting for hard starting, low output, fuel, compression, and injection timing faults, with piping and wiring diagrams in the appendix.
It is a 263 page PDF download that repeats the material in French, German, Spanish, Italian, and Swedish, so you can print the maintenance pages and keep them at the bench.
Complete the set for your GM Series
What's Inside This Yanmar GM Series Manual
| System | Pages | Key Topics |
|---|---|---|
| Safety & Precautions | 5-7 | Name of Parts, Fire Prevention, Exhaust Gas Prevention, Burn Prevention, General Safety Tips, Battery Charging Safety |
| Machine Identification | 9-10 | Air Intake Side Parts, Exhaust Side Parts, Cylinder Number Identification |
| Specifications | 11-14 | Direct Sea Water Cooling Type Gm Series, Direct Sea Water Cooling Type Gmf Series, Direct Sea Water Cooling Type GMV-series, Fresh Water Cooling Type GMFV-series |
| Engine Handling Fundamentals | 15-16 | Running-In Operation, Fuel Management, Lubrication Management, Cooling System Care, Drive Belt Adjustment, Starting Procedures |
| Installation | 17-22 | Engine Mounting, Engine Centering, Exhaust System, Sea Water Cooling System, Fuel System, Electric System |
| Fuel, Lube Oil & Cooling Water | 23-25 | Fuel Oil Selection and Handling, Lube Oil Selection and Supply, Cooling Water Handling, Cooling Water Supply and Check, Cooling Water Refilling |
| Break-In & Operation | 26-32 | Fuel Oil Supply and Draining, Lube Oil Supply, Air Bleeding, Engine Parts Lubrication, Safety Checks, Pilot Lamp Check, Starting, Cautions After Engine Starting, During Engine Operation, Engine Stopping, Draining the Cooling Water |
| Maintenance & Storage | 33-40 | Fuel Oil System, Lube Oil System, Cooling Water System, Battery Maintenance, V-Belt Tension Adjustment, Engine Body Checks, Engine Cleaning, Lube Oil Change, Engine Coating/Covering, Battery Removal/Charging |
| Troubleshooting | 41-42 | |
| Francais | 43-82 | |
| Deutsch | 83-121 | |
| Espanol | 122-160 | |
| Italiano | 161-199 | |
| Svensk | 200-237 | |
| Appendix: Component Diagrams | 238-262 | Piping Diagrams, Wiring Diagrams, Fuel Oil System Components, Lubricating Oil System Components, Cooling Water System Components, Electrical System Components |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| All Models | ||
| Starter motor power | DC 12V, 1.0kW | p. 11 |
| Minimum radius of cable bend | 200 mm (7.9 in.) | p. 24 |
| Fuel injection pressure | 170 ± 5 kg/cm² (2347 - 2489 lb/in.²) | p. 11 |
| Bore x Stroke | 75 x 72 mm (2.95 x 2.83 in) | p. 11 |
| Compression Ratio | 23.0 | p. 11 |
| Replace Fuel Filter Interval | Every 300 hrs | p. 34 |
| Replace Lube Oil Filter Interval | 1st time after 50 hrs, 2nd time and thereafter every 300 hrs | p. 35 |
| Adjust Valve Clearance Interval | Every 600 hrs | p. 38 |
| Cooling Water Pump Belt Tension (Fresh water) | 10 mm (with 10 kg thumb force) | p. 36 |
| Cooling Water Pump Belt Tension (Sea water) | 5-7 mm (with 10 kg thumb force) | p. 36 |
| 1GM10, 2GM20, 1GM10V, 2GM20V, 2GM20F, 2GM20FV | ||
| Fuel Injection Timing (1- and 2-cylinder models) | 15° ± 1° b.T.D.C. | p. 11 |
| 3GM30, 3GM30F, 3GM30V, 3GM30FV | ||
| Fuel Injection Timing (3-cylinder models) | 18° ± 1° b.T.D.C. | p. 11 |
