Used Yanmar 3JH5E 39HP Inboard Diesel Engine: A Complete Guide for Boaters

If you’re in the market for a reliable inboard diesel engine, the Yanmar 3JH5E 39HP is a model worth considering. Known for its durability, fuel efficiency, and compact design, this engine is a favorite among sailboat and small yacht owners. This guide will cover everything you need to know about purchasing, maintaining, and getting the most out of a used Yanmar 3JH5E.

Overview of the Yanmar 3JH5E Engine

The Yanmar 3JH5E is a 3-cylinder, 39 horsepower inboard diesel engine, designed for small to medium-sized vessels. It combines compact dimensions with robust performance, making it ideal for both coastal cruising and offshore sailing. Key specifications include:

• Power Output: 39 HP

• Engine Type: 3-cylinder, liquid-cooled diesel

• Displacement: 1.64 liters

• Fuel Injection: Direct injection for better fuel efficiency

• Cooling System: Freshwater-cooled with heat exchanger

• Rated RPM: 3,000

Yanmar engines are well-known for their long service life and relatively low maintenance costs, making the 3JH5E a smart investment for boaters who want reliability without breaking the bank.

Advantages of Buying a Used Yanmar 3JH5E

Purchasing a used Yanmar 3JH5E can be an excellent choice for those looking to upgrade or replace their inboard engine without paying for a brand-new unit. Benefits include:

1. Cost Savings: A used engine can be 40–60% cheaper than a new one while still offering excellent performance.

2. Proven Reliability: Yanmar engines have decades of a reputation for durability. Many used units have logged thousands of hours with minimal issues.

3. Compact Design: Easy to fit into smaller engine compartments or retrofitting projects.

4. Fuel Efficiency: Diesel engines are more economical and last longer than gasoline counterparts.

5. Parts Availability: Replacement parts are widely available through marine dealers and online suppliers.

Things to Consider When Buying a Used Yanmar 3JH5E

Buying a used inboard diesel engine requires careful inspection to avoid costly repairs. Here are some key factors to evaluate:

1. Engine Hours

Check the total hours on the engine. Diesel engines are typically rated for 5,000–10,000 hours of operation, but the condition of the engine is more important than the hours alone.

2. Maintenance Records

Ask for full maintenance records. Engines that have had regular oil changes, fuel filter replacements, and heat exchanger flushes will last much longer.

3. Signs of Corrosion or Leaks

Inspect for rust, corrosion, and leaks around the engine block, hoses, and connections. These can indicate neglect or long-term exposure to saltwater.

4. Compression Test

A compression test can reveal the internal health of the engine cylinders. A significant drop in compression may signal worn pistons or valves.

5. Turbo and Exhaust System

Ensure the turbo (if fitted) and exhaust system are in good condition. Excessive smoke or unusual noises can indicate issues.

Maintenance Tips for the Yanmar 3JH5E

Proper maintenance ensures your Yanmar 3JH5E continues to perform at its best. Follow these essential maintenance tips:

1. Regular Oil Changes: Every 100–150 hours or once a year, whichever comes first.

2. Fuel System Care: Replace fuel filters regularly and use a high-quality diesel to prevent injector clogging.

3. Cooling System Flush: Annually flush the heat exchanger to prevent corrosion.

4. Belts and Hoses: Check for wear or cracking and replace as needed.

5. Winterization: If storing the boat for winter, ensure the engine is properly winterized to avoid freeze damage.

Where to Buy a Used Yanmar 3JH5E

Several options exist for purchasing a used Yanmar 3JH5E:

• Marine Dealerships: Certified pre-owned engines with warranty options.

• Online Marketplaces: Websites like YachtWorld, eBay, or Craigslist often list used engines.

• Boat Salvage Yards: Engines from decommissioned boats can offer excellent value.

• Local Marinas: Some marinas sell upgraded engines from customer boats.

Always verify the engine’s history and consider a pre-purchase survey by a qualified marine mechanic.

Cost of a Used Yanmar 3JH5E

The price of a used Yanmar 3JH5E varies depending on hours, condition, and included components. As of 2025, you can expect to pay:

• Low-Hours Engines: $6,000–$9,000

• Moderate-Hours Engines: $4,500–$6,000

• High-Hours Engines or Salvaged Units: $2,500–$4,500

Prices can fluctuate based on location and demand, so research local listings before making a purchase.

Conclusion

The Yanmar 3JH5E 39HP inboard diesel engine remains a top choice for boaters seeking a balance between power, efficiency, and reliability. Buying a used engine can save money while still providing many years of dependable service, provided you carefully inspect and maintain it. With its compact size, robust design, and widespread parts availability, the 3JH5E is a practical and smart choice for sailboats and small yachts.

FAQs: Used Yanmar 3JH5E

Q1: How long does a Yanmar 3JH5E engine last?
A1: With proper maintenance, these engines can last over 5,000 hours, often exceeding 20 years for casual cruising.

Q2: Is the 3JH5E suitable for a sailboat?
A2: Yes, its compact design and reliable power make it ideal for sailboats and small motor yachts.

Q3: Can I retrofit a 3JH5E into an older boat?
A3: Absolutely. Its compact dimensions and standard shaft configuration make retrofits straightforward.

Q4: Where can I find replacement parts?
A4: Parts are widely available through Yanmar dealers, marine supply stores, and online marketplaces like Boats.net or eBay.

Q5: What’s the difference between new and used 3JH5E engines?
A5: A new engine comes with warranty protection and zero wear, while a used engine can offer significant cost savings but requires careful inspection.