New
Yanmar53 HP
Yanmar 4JH45E 53.8HP
diesel
$4,050.00
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New
Yanmar
Yanmar 3JH40 40 HP
$3,650.00
The Yanmar 3JH40 is a compact, efficient 40 HP marine diesel engine featuring modern common-rail fuel injection. Designed for sailboats, yachts, and small workboats, it offers excellent fuel economy, low emissions, and reliable performance in a lightweight.
Horsepower
40 HP
Fuel Type
diesel
Displacement
1.642 L /100 cu in
Stroke
4-stroke
Rated Output
29.4kW/ 40mhp
Rated Speed
3000rpm
In Stock (3 available)
Free shipping on orders over $500
90-day warranty included
Description
The Yanmar 3JH40 is one of the smallest common-rail marine diesel engines produced by Yanmar. With its three-cylinder configuration and Bosch common-rail direct injection system, it delivers smooth power and quiet operation while meeting strict emission standards (EPA Tier 3 / EU RCD 2). It’s ideal for repowering older boats or installing in new builds where compact size and weight savings are priorities.
Specifications
SKUY896017
BrandYanmar
CategoryInboard Engines
ConditionNew
Horsepower40 HP
Fuel Typediesel
Displacement1.642 L /100 cu in
No. of Cylinders3 cylinders
Stroke4-stroke
Weight423.00 lbs
Rated Output29.4kW/ 40mhp
Rated Speed3000rpm
Cylinder Bore x Stroke88mm x 90mm/ 3.46 in x 3.54 in
Combustion SystemDirect Injection, Bosch Common Rail System
AspirationNatural
Alternator12V - 125A
Dry Weight192kg/423lbs
Dimensions774mmx 580mm x 632mm
ControlsMechanical (optional - VC10 system)
CertificationsRCD 2 EPA Tier 3 EPA Tier 3C BSO II EMC SOLAS
Frequently Asked Questions
What is the Yanmar 3JH40 engine?
The Yanmar 3JH40 is a 3-cylinder, 4-stroke, vertical water-cooled marine diesel engine with 40 metric horsepower (mhp) at 3000 rpm, designed for small pleasure craft and light commercial vessels. It uses advanced Bosch Common Rail fuel injection for efficiency and low emissions.
What are the key technical specifications?
Rated Output: 29.4 kW / 40 mhp 3000 rpm Displacement: 1.642 L (100 cu in) Cylinders: 3 inline Combustion: Direct injection with Bosch Common Rail system Aspiration: Naturally aspirated Alternator: 12 V – 125 A Dry Weight (no gear): ~192 kg (423 lbs) Dimensions: ~774 × 580 × 632 mm Controls: Mechanical (optional electronic VC20/VC10)
What makes this engine different from older diesel models?
The 3JH40 uses common rail diesel technology, which improves fuel atomization and combustion control. This results in better fuel economy, quieter operation, and lower emissions compared with older mechanical injection engines.
What cooling system does the engine use?
It has a freshwater cooling system with a heat exchanger and a seawater impeller pump, which helps regulate operating temperature while protecting internal engine parts from corrosion.
What boats is the 3JH40 suited for?
This engine is suitable for sailboats (monohulls and catamarans up to ~45 ft), small motorboats, tenders, and light-duty commercial craft, whether for new builds or repowering older vessels.
What’s included in the standard engine package?
Exhaust mixing elbow (L-type) Alternator (12 V, 125 A) B25 control panel Flexible engine mounts Mechanical throttle sensor Fuel pre-filter with water separator Freshwater expansion tank Belt safety cover .
What optional accessories are available?
High-riser mixing elbow Secondary alternator (12 V or 24 V) C35 control panel Extension wiring harnesses Second station controls TFX sidemount control head VC10/VC20 vessel control systems NMEA2000 engine monitoring SOLAS certification package Hot water kit Saildrive leg extensions
What kind of maintenance does the engine require?
Oil and filter changes per hours/season Fuel system filters and water separator servicing Coolant level and seawater impeller checks Belts and hoses inspections
Can I do maintenance myself?
Basic checks (oil level, coolant, belts) can be done by knowledgeable owners, but major servicing and electronic diagnostics should be done by an authorized marine technician to ensure correct procedures and keep warranties valid.
What type of fuel and oil should be used?
Use quality marine diesel fuel that conforms to local standards. For oil, choose a diesel engine oil meeting the specifications recommended in the Yanmar manual (e.g., appropriate SAE grade and API class). Check the manual for exact grades based on climate and usage.
Why choose the Yanmar 3JH40?
Advanced common rail fuel system for efficiency. Low noise and emissions. Ideal for sailboat auxiliary or primary propulsion.
