New
Yanmar53 HP
Yanmar 4JH45E 53.8HP
diesel
$4,050.00
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New
Yanmar
Yanmar 4JH45 45HP
$3,675.00
Yanmar 4JH45 — 45 HP liquid-cooled 4-cylinder marine diesel engine with direct injection for efficient and dependable propulsion.
Horsepower
45 HP
Fuel Type
diesel
Displacement
2.19 L / 131 cu. in
Rated Output
33.1 kW / 45 mhp
Rated Speed
3000 rpm
In Stock (3 available)
Free shipping on orders over $500
90-day warranty included
Description
The Yanmar 4JH45 is a compact, reliable 4-cylinder marine diesel engine with advanced Bosch common-rail direct injection for improved fuel efficiency, lower emissions, and quieter operation. It’s well-suited for sailboats, small yachts, and pleasure craft, offering smooth performance, robust build quality, and wide global service support.
Specifications
SKUY712146
BrandYanmar
CategoryInboard Engines
ConditionNew
Horsepower45 HP
Fuel Typediesel
Displacement2.19 L / 131 cu. in
No. of Cylinders4 cylinders
Rated Output33.1 kW / 45 mhp
Rated Speed3000 rpm
Cylinder Bore x Stroke88 mm x 90 mm / 3.46 in x 3.54 in
Combustion SystemDirect Injection, Bosch Common Rail System
AspirationNatural
Alternator12V - 125A
Dry Weight220 kg / 485 lbs
Dimensions870 mm x 589 mm x 627 mm
ControlsMechanical
CertificationsRCD 2 EPA Tier 3 EPA Tier 3C BSO II EMC SOLAS
Frequently Asked Questions
What is the Yanmar 4JH45 engine?
The Yanmar 4JH45 is a 4-cylinder, 4-stroke, vertical water-cooled diesel marine engine producing about 45 metric horsepower (mhp) at 3000 rpm. It belongs to Yanmar’s JH-CR (Common Rail) series, known for modern diesel technology and reliable operation in marine applications.
What are the main technical specifications?
Rated Output: ~33.1 kW / 45 mhp at 3000 rpm Displacement: 2.19 L (131 cu in) Cylinders: 4 inline Combustion: Direct injection with Bosch Common Rail system Aspiration: Naturally aspirated Alternator: 12 V – 125 A Dry Weight (no gear): ~220 kg / 485 lbs Dimensions: 870 × 589 × 627 m Controls: Mechanical (optional VC10 electronic system)
What fuel system does this engine use?
The 4JH45 uses a Bosch Common Rail direct injection fuel system, providing smoother combustion, improved fuel efficiency, reduced emissions, and quieter operation compared to older mechanical pumps.
What types of boats is the 4JH45 suited for?
It’s commonly used in sailboats, catamarans, small yachts, and custom recreational vessels where reliable medium-power propulsion is needed. Its size and power make it ideal for boats around ~8–12 m (26–40 ft)
What are standard components included with the engine?
Exhaust mixing elbow (L-type) Freshwater expansion tank Fuel pre-filter with water separator Flexible engine mounts B25 engine panel Mechanical throttle sensor Belt safety cover
Are there optional accessories available?
Yes — you can add accessories such as: Secondary alternator (12 V or 24 V). Extended harnesses. TFX sidemount control head. VC10 vessel control system. NMEA2000 engine monitoring. Hot water kits and more.
What kind of cooling system does it use?
The engine uses a freshwater cooling system with a heat exchanger and a seawater pump with rubber impeller. This protects the engine from corrosion and helps maintain stable operating temperatures.
What transmission options are compatible?
Common marine gear options include KM35P, KM4A2, ZF25A, ZF30M, and SD60 saildrive, depending on boat configuration and installation preferences.
What maintenance should be done regularly?
Engine oil & filter changes at regular hourly intervals Fuel filter and water separator servicing Coolant checks and seawater impeller inspection Belt and hose condition checks
How fuel efficient is the 4JH45?
Actual consumption varies with boat load and cruising speed, but engines with common rail technology are generally more fuel-efficient and produce better torque at lower rpms than older designs. Precise consumption figures depend on settings and conditions.
