Yanmar 3YM30 Marine Diesel Engine

The Yanmar 3YM30 is a compact, reliable, and fuel-efficient inboard marine diesel engine delivering 29–30 HP, designed for sailboats, small yachts, and auxiliary propulsion applications. As part of Yanmar renowned YM series, the 3YM30 combines durability, smooth performance, and low emissions, making it a trusted choice for boat owners worldwide.

Engine Design & Construction

The 3YM30 features a 3-cylinder, 4-stroke diesel configuration with direct fuel injection, providing consistent power and smooth torque across the operating range. Its robust construction and high-quality components are built to withstand continuous operation in challenging marine conditions.

Equipped with a freshwater cooling system with heat exchanger, the engine maintains optimal operating temperatures while protecting internal components from corrosion. The compact and lightweight design allows installation in tight engine compartments and ensures easy access for maintenance.

Performance & Efficiency

Delivering 30 HP at 3,200 RPM, the Yanmar 3YM30 offers smooth, dependable propulsion for cruising, docking, and maneuvering. Its torque characteristics at low and mid-range RPM make it ideal for displacement hulls and sailboats that require consistent thrust and precise control.

The engine’s direct fuel injection system ensures high fuel efficiency, reducing operational costs while maintaining reliable performance.

Marine Integration

The 3YM30 is compatible with marine gearboxes and conventional shaft-drive systems, providing flexible installation options. Its balanced 3-cylinder design minimizes vibration and noise, improving onboard comfort.

Ease of Maintenance & Reliability

The Yanmar 3YM30 is designed for easy maintenance, with accessible filters, belts, and other service points. Its simplicity and durability reduce downtime and long-term maintenance costs. Yanmar global support network ensures availability of spare parts, guaranteeing long-term reliability.

Ideal Applications

The Yanmar 3YM30 Diesel Engine is ideal for:

• Sailboats and auxiliary propulsion systems

• Small to medium cruising yachts

• Coastal and inland waterways

• Owners seeking a compact, reliable, and fuel-efficient marine diesel engine

Key Advantages

• Proven Yanmar marine diesel reliability

• Compact and space-efficient design

• Fuel-efficient 3-cylinder direct injection engine

• Freshwater cooling with heat exchanger

• Smooth operation with low vibration and noise

• Easy maintenance with strong global parts support

Technical Specifications

General

• Model: Yanmar 3YM30

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

• Fuel System: Direct fuel injection

• Aspiration: Naturally aspirated

• Number of Cylinders: 3 inline

Displacement & Combustion

• Displacement: Approx. 1.64 liters

• Bore × Stroke: 75 mm × 78 mm

• Combustion Chamber: Direct injection diesel

Performance

• Rated Power: 29–30 HP (22–22.5 kW) @ 3,200 RPM

• Rated Speed: 3,200 RPM

• Maximum Torque: Optimized for low- to mid-range RPM marine operation

• Fuel Consumption: Low, dependent on load and propeller match

Cooling & Lubrication

• Cooling System: Freshwater cooling with heat exchanger

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

• Engine Oil Capacity: Approx. 6 liters

• Recommended Oil Type: Marine-grade diesel engine oil

Electrical System

• Starting System: 12 V electric start

• Alternator: 12 V marine alternator for onboard electrical systems

Dimensions & Weight

• Overall Dimensions (L × W × H): Approx. 870 × 520 × 600 mm

• Dry Weight: Approx. 210–230 kg (engine only, excluding gearbox)

Drive & Installation

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

• Drive Type: Inboard shaft drive

• Compatible Gearbox: Marine gearbox compatible with small inboard engines

• Mounting: Flexible engine mounts

Service & Adjustment

• Valve Clearance (Cold): Intake: 0.20 mm / Exhaust: 0.25 mm

• Firing Order: 1 – 2 – 3

• Maintenance Access: Easy access to filters, belts, and service points