The Yanmar 4JH45 Marine Diesel Engine is a 4-cylinder, 4-stroke common rail (CR) direct injection diesel engine that delivers 45hp at 3000 rpm. As part of the 4JH series, the 4JH45 is designed for sailboats, yachts, and light-duty commercial vessels, offering excellent power, fuel efficiency, and low emissions. With its common rail direct injection system, this engine provides smooth operation, superior fuel efficiency, and low exhaust emissions, making it compliant with the latest global environmental regulations, including EPA Tier 3 and EU RCD Stage II.
The 4JH45 is equipped with a freshwater cooling system via a heat exchanger, ensuring optimal operating temperatures and preventing corrosion. This engine is compact and lightweight, making it easy to install in most engine compartments. It is known for its low vibration and quiet performance, contributing to a comfortable onboard experience.
Technical Specifications:
- Engine Model: 4JH45
- Engine Type: 4-cylinder, 4-stroke, vertical water-cooled diesel engine
- Displacement: 2.19 litres (2190 cc)
- Bore x Stroke: 84 mm x 90 mm
- Power Output: 45hp (33.1 kW) at 3000 rpm
- Compression Ratio: 18.9:1
- Fuel System: Common rail direct injection (CR)
- Cooling System: Freshwater cooling with heat exchanger
- Alternator Output: 12V – 125A
- Lubrication System: Forced lubrication by gear pump
- Oil Capacity: 7.4 litres
- Starting System: Electric start
- Direction of Rotation: Counterclockwise (viewed from flywheel)
- Weight: 192 kg (without gearbox)
- Gearbox Options: KM35P, KM4A2 (mechanical or hydraulic)
- Reduction Ratios: 2.14:1, 2.61:1 (KM35P) or 2.20:1, 3.12:1 (KM4A2)
- Exhaust System: Water-cooled, with wet exhaust manifold
- Fuel Consumption: Approx. 7.0 litres/hour at cruising speed
- Emission Compliance: EPA Tier 3, EU RCD Stage II compliant
Key Features:
- Common Rail Direct Injection (CR): Enhances fuel efficiency, reduces emissions, and improves power output.
- Compact and Lightweight Design: Ideal for sailboats and yachts with limited engine compartment space.
- Freshwater Cooling System: Protects engine from corrosion and maintains optimal operating temperatures.
- Low Noise and Vibration: Designed for smooth, quiet operation, enhancing onboard comfort.
- Environmentally Friendly: Complies with EPA Tier 3 and EU RCD Stage II regulations, ensuring low emissions.
- Fuel Efficiency: Delivers excellent fuel economy, especially during extended cruising.
Yanmar is a globally recognised leader in marine diesel engine manufacturing, known for producing reliable, fuel-efficient, and environmentally-friendly engines. The 4JH45 is part of Yanmar’s advanced JH-series, offering modern common rail technology and compliance with strict emissions regulations for sailboats and small vessels.
Yanmar provide several transmission options for various marine applications. The KM35P is a mechanical marine gearbox with hydraulic control, suitable for inboard installations. The KM4A-2 is designed specifically for sailboats, featuring a mechanical servo cone clutch and multiple gear ratios for efficient propulsion. The SD60 SailDrive offers a smooth, low-vibration drive system for sailboats, optimizing performance with specific Yanmar engines. Additionally, ZF25A is another reliable transmission option for Yanmar engines, known for its durability in demanding marine environments. A bobtail engine is a fully assembled replacement engine, designed to replace existing engines and their systems, available for stern drive and inboard setups. These come with critical systems such as fuel, electrical, cooling, and exhaust, providing a comprehensive solution for repowering boats.
