Yanmar 2YM15 Marine Diesel Engine: Lightweight 14hp Performance
Modern Efficiency and Smooth Power for Trailable Sailboats and Small Craft
Introduction
The Yanmar 2YM15 marine diesel engine represents a significant leap forward in lightweight diesel technology, offering a perfect blend of modern efficiency and reliable power in an incredibly compact package. At Wave Inboard Motors, our certified Yanmar technicians have extensive hands-on experience with the entire YM series, and the 2YM15 stands out as the premier choice for sailors where every pound matters. This 14hp marine diesel engine delivers the smoothness and reliability of a modern design without the weight penalty of older generations.
Engineered as the ideal lightweight sailboat engine for vessels from 26 to 30 feet—especially those that are trailered or performance-oriented—the 2YM15 provides ample power for propulsion and reliable battery charging. Its modern fuel injection system ensures exceptional fuel efficiency and smoother operation than any comparable two-cylinder engine from the past. When you choose a new or professionally remanufactured Yanmar 2YM15 for sale, you’re investing in a modern powerplant that enhances your vessel’s performance and value.
This page will detail its technical specifications, show how it outperforms older models, and help you understand why it is the definitive choice for a modern marine diesel repower in its class.
Technical Specifications Table
| Specification | Detail |
|---|---|
| Model | Yanmar 2YM15 |
| Engine Type | 2-Cylinder, 4-stroke, water-cooled diesel |
| Displacement | 0.5 L (500 cc) |
| Max Output | 14.5 HP (10.7 kW) @ 3400 RPM |
| Bore x Stroke | 62 mm x 66 mm |
| Compression Ratio | 23.0:1 |
| Cooling System | Heat Exchanger (Closed-Cooling) |
| Starting System | 12V Electric Start |
| Alternator Output | 12V – 40A |
| Dry Weight | 88 kg (194 lbs) |
| Dimensions (LxWxH) | Approx. 610mm x 500mm x 500mm |
| Gear Ratio | 2.62:1 (Standard on KM2A Gear) |
Competitor Comparison Table
| Feature | Yanmar 2YM15 (Modern Diesel) | Yanmar 1GM10 (Older Diesel) | Beta Marine 14 (Kubota-Based) |
|---|---|---|---|
| Engine Type | 2-Cylinder, Modern Electronic | Single-Cylinder, Mechanical | 2-Cylinder, Electronic |
| Power (HP) | 14.5 HP @ 3400 RPM | 9 HP @ 3600 RPM | 14 HP @ 3000 RPM |
| Smoothness | Very Good (Modern balanced design) | Poor (Pronounced single-cyl vibration) | Good (Kubota industrial base) |
| Weight | 194 lbs (88 kg) | 145 lbs (66 kg) | 220 lbs (100 kg) |
| Reliability | Exceptional (Proven YM Series) | Exceptional (But older tech) | Excellent (Kubota Block) |
| Cooling System | Heat Exchanger (Standard) | Raw Water Cooling | Heat Exchanger (Standard) |
| Key Differentiator | Lightest modern diesel, smooth | Lightest overall, simplest | Industrial Kubota reliability |
Verdict: The Yanmar 2YM15 wins as the most advanced and refined option, offering the best balance of light weight, modern smoothness, and Yanmar’s marine-specific engineering. It is a dramatic upgrade in power and smoothness over the 1GM10. While the Beta 14 is also an excellent engine, the 2YM15 is significantly lighter, making it the preferred choice for performance-oriented and trailered boats where weight is a critical factor.
Replacement Options Table
| Consideration | Rebuild Older Engine (e.g., 1GM10) | Install Remanufactured 2YM15 | Install Brand New 2YM15 |
|---|---|---|---|
| Condition | Outdated technology, single-cylinder vibration | Like-new, zero hours, modern performance | Perfect, factory-fresh with latest updates |
| Warranty | None (on rebuild itself) | Full 1-Year Parts & Labor Warranty | Full Yanmar Factory Warranty |
| Power | Original 9HP | 14.5 HP | 14.5 HP |
| Noise/Vibration | High (single-cylinder vibration) | Low (Modern, balanced design) | Lowest |
| Total Project Value | Lowest (Investing in old tech) | High (Best value for performance) | Highest (Peak performance & warranty) |
Expert Recommendation: For most owners looking to upgrade from an older single-cylinder engine, a professionally remanufactured Yanmar 2YM15 offers transformative value. The jump from a rough, vibrating single-cylinder to a smooth, modern two-cylinder is immense and well worth the investment. You gain significant horsepower, modern features like standard fresh-water cooling, and a much more pleasant onboard experience. While a new engine is excellent, the cost savings of a remanufactured model make it the smart choice for this class of repower.
Pros and Cons Table
| Pros | Cons |
|---|---|
| Extremely Lightweight for a Modern Diesel | Higher initial cost than older single-cylinder models |
| Modern, Fuel-Efficient Design | Not as smooth as a three-cylinder engine (e.g., 3YM20) |
| Smoother than Older Single-Cylinder Engines | Modern electronics require proper installation |
| Heat Exchanger Cooling for Longevity | |
| Excellent Parts & Service Support Worldwide |
Link to Our Core Service Pages:
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“Ensure optimal performance and warranty compliance with our certified 【Yanmar Engine Installation Services】.”
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“Protect your investment with our tailored 【Annual Marine Engine Maintenance】 plans.”
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“Our experts can manage your entire 【Small Sailboat Repower Project】 from start to finish.”
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“We provide genuine 【Yanmar Marine Engine Parts】 and filters for all your service needs.”
Link to Informational Blog Posts:
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“Is it the right time? Learn the 【5 Signs You Need a Marine Engine Repower】.”
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“Understand the benefits in our guide 【Upgrading from a Single to Twin Cylinder Marine Engine】.”
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“Planning your project? We break down the 【Costs of Repowering a Small Sailboat】.”
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“Maximize performance by 【Choosing the Right HP for Your Trailable Sailboat】.”

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