Yanmar 2GM20F Marine Diesel Engine

The Yanmar 2GM20F Marine Diesel Engine is a compact, dependable, and fuel-efficient 2-cylinder inboard marine diesel engine designed for auxiliary propulsion in sailboats and small vessels. Known worldwide for its reliability and simplicity, the 2GM20F has become a trusted choice for boat owners seeking consistent performance with low operating and maintenance costs.

Engine Design & Construction

The 2GM20F features a 2-cylinder, vertical, 4-stroke diesel configuration with direct fuel injection, ensuring efficient combustion and dependable torque delivery. Its robust construction and high-quality materials are engineered to withstand harsh marine environments, providing long service life even under continuous use.

A freshwater cooling system with heat exchanger helps maintain stable operating temperatures and protects internal components from corrosion caused by saltwater exposure. The engine’s compact layout allows easy installation in confined engine compartments while still offering good access for routine maintenance.

Performance & Efficiency

Producing approximately 18 horsepower, the Yanmar 2GM20F delivers smooth and steady propulsion ideal for cruising, docking, and auxiliary sailing operations. The engine is optimized for low fuel consumption, making it an economical solution for long-distance cruising and everyday marine use.

Its torque characteristics at low and mid-range RPM provide excellent control and responsiveness, particularly valuable for sailboats and displacement hull vessels.

Marine Integration

Designed specifically for marine applications, the 2GM20F is compatible with marine gearboxes and shaft drive systems, allowing flexible installation options. Its balanced design contributes to reduced vibration and quieter operation, enhancing onboard comfort during extended voyages.

Ease of Maintenance & Reliability

One of the key strengths of the Yanmar 2GM20F is its simple and service-friendly design. Routine service points such as filters, belts, and pumps are easily accessible, reducing downtime and simplifying maintenance tasks. The engine’s widespread use ensures strong spare parts availability and long-term support.

Ideal Applications

The Yanmar 2GM20F is well suited for:

• Sailboats and auxiliary propulsion systems

• Small yachts and cruising vessels

• Coastal and inland waterway boats

• Owners seeking a proven, low-maintenance marine diesel engine

Key Advantages

• Proven Yanmar marine diesel reliability

• Compact and space-efficient design

• Fuel-efficient 2-cylinder direct injection engine

• Freshwater cooling with heat exchanger

• Smooth operation with low vibration

• Easy maintenance and strong parts availability

Technical Specifications

General

• Model: Yanmar 2GM20F

• Engine Type: 4-stroke, vertical, water-cooled marine diesel

• Fuel System: Direct fuel injection

• Aspiration: Naturally aspirated

• Number of Cylinders: 2 inline

• Displacement: 1,061 cc (1.06 L)

• Bore × Stroke: 80 mm × 84 mm

Performance

• Rated Power: 18 HP (13.2 kW) @ 3,000 RPM

• Rated Speed: 3,000 RPM

• Torque: Approx. 52 Nm @ 2,000–2,500 RPM

• Fuel Consumption: Efficient low-load marine consumption (varies with load/propeller)

Cooling & Lubrication

• Cooling System: Freshwater cooling with heat exchanger

• Lubrication System: Forced lubrication with gear-type oil pump

• Engine Oil Capacity: Approx. 5.5 liters

• Lubrication Oil Pressure: Normal operating pressure ~3.0–4.0 kgf/cm²

Electrical System

• Starting System: 12 V electric start

• Starter Output: 1.1–1.4 kW

• Alternator/Generator: 12 V charging system

Dimensions & Weight

• Overall Dimensions (L × W × H): Approx. 693 × 489 × 582 mm

• Dry Weight: Approx. 150–160 kg (engine only; excludes gearbox and mounting hardware)

Drive & Installation

• Rotation (Crankshaft): Counter-clockwise (viewed from flywheel end)

• Mounting Flange: SAE standard marine mounting

• Compatible Gearbox: Marine gearbox compatible with small inboard engines

• Propeller Shaft Rotation: Clockwise (viewed from stern)

Service & Adjustment

• Valve Clearance (Cold): Intake ~0.20 mm / Exhaust ~0.20 mm

• Fuel Injection Timing: Set for optimal combustion timing

• Firing Order: 1-2

• Recommended Maintenance Intervals: Per Yanmar marine service schedule (oil, filters, belts, cooling system)