Definition
The Yanmar 2GM20 is a small, two‑cylinder, four‑stroke diesel engine manufactured by Yanmar Co., Ltd., a Japanese company specializing in diesel power units for agricultural, marine, and industrial applications.
Overview
The 2GM20 belongs to Yanmar’s “2GM” series of compact diesel engines, which are widely used in small generators, irrigation pumps, marine auxiliary power, and other low‑power equipment. The engine is designed for durability and fuel efficiency in continuous‑operation settings. It is typically water‑cooled, equipped with a direct‑fuel injection system, and operates at a maximum speed of around 3,500 rpm. According to Yanmar’s published specifications, the engine delivers a rated power output in the range of 3.5 kW to 4 kW (approximately 5–5.5 hp) at its rated speed.
Etymology / Origin
The designation “2GM20” follows Yanmar’s internal naming convention for its small diesel engines:
- 2 – indicates the number of cylinders.
- GM – denotes the engine series; the “GM” series comprises compact, air‑cooled or water‑cooled diesel units intended for light‑duty use.
- 20 – identifies the specific model within the series, often related to displacement class or design revision.
Yanmar Co., Ltd. was founded in 1912 (originally as Osaka Engine Works) and adopted the name “Yanmar” in 1933, a contraction of “Yama” (mountain) and “maru” (a traditional suffix for ships), reflecting the company’s origins in agricultural machinery and later expansion into marine propulsion.
Characteristics
| Feature | Typical Specification* |
|---|---|
| Configuration | 2‑cylinder, inline |
| Cycle | Four‑stroke |
| Cooling | Water‑cooled (some variants may be air‑cooled) |
| Displacement | Approximately 0.5 L (≈ 495 cc) |
| Rated Power | 3.5 kW – 4 kW (≈ 5 – 5.5 hp) at 3,500 rpm |
| Fuel System | Direct fuel injection, mechanically governed |
| Fuel Type | Diesel (light diesel oil) |
| Starting Method | Electric starter (with optional manual pull‑start) |
| Applications | Portable generators, water pumps, small marine auxiliary engines, agricultural equipment |
| Compliance | Meets applicable emissions standards for small stationary engines in many jurisdictions (e.g., EU Stage V, US EPA Tier 4i) |
*Exact specifications may vary by production year and regional market; the values presented reflect the most commonly cited data in Yanmar’s public product literature.
Related Topics
- Yanmar diesel engines – broader range of gasoline and diesel engines produced by Yanmar for various sectors.
- Small diesel engines – category of low‑displacement diesel power units used in portable equipment.
- Marine auxiliary power – secondary engines on boats and ships used for electricity generation and pump operation.
- Generator sets (gensets) – combined engine–alternator units where engines like the 2GM20 serve as the prime mover.
- Agricultural mechanization – the use of compact diesel engines in irrigation, grain handling, and other farm tasks.
The information presented above is derived from Yanmar’s publicly available product specifications and standard industry references. Where precise data are not publicly disclosed, the entry reflects the most reliable and commonly reported figures.