Yanmar 4LV170 (Z) 170HP Inboard Diesel Engine: Ultimate Guide & Review

When it comes to marine propulsion systems, the Yanmar 4LV170 (Z) 170HP Inboard Diesel Engine stands out as a powerhouse renowned for its durability, efficiency, and advanced technology. Whether you’re a professional marine engineer, a boat owner, or simply a marine enthusiast seeking reliable engine options, the Yanmar 4LV170 (Z) offers a compelling blend of power and performance that’s hard to beat.

In this comprehensive article, we’ll explore everything you need to know about the Yanmar 4LV170 (Z) engine — from its technical specifications, unique features, benefits, applications, maintenance tips, and why it remains a top choice for inboard marine diesel engines globally.

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Overview of the Yanmar 4LV170 (Z) Diesel Engine

The Yanmar 4LV170 (Z) is a four-cylinder, 4.3-liter turbocharged and aftercooled marine diesel engine, delivering a solid 170 horsepower (HP). It belongs to Yanmar’s popular LV series, known for cutting-edge engineering and eco-friendly performance.

Designed with both commercial and recreational marine vessels in mind, the 4LV170 (Z) engine offers a perfect balance of power and fuel efficiency, ideal for sailboats, trawlers, fishing boats, and other inboard-powered vessels.

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Key Features and Specifications

Here’s a breakdown of the essential technical specifications and features that make the Yanmar 4LV170 (Z) engine stand out:

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Advanced Technology and Design

1. Common Rail Direct Injection (CRDI)

The 4LV170 (Z) engine utilizes a modern common rail direct injection system that allows precise control over fuel injection timing and pressure. This results in:

• Enhanced fuel efficiency

• Reduced exhaust emissions

• Smooth engine operation and lower noise levels

2. Turbocharging and Aftercooling

Equipped with a turbocharger and aftercooler, the engine maximizes air intake density, which translates to higher combustion efficiency and increased power output without sacrificing fuel economy.

3. Emission Compliance

Yanmar has engineered the 4LV170 (Z) to meet stringent emission standards such as IMO Tier II and EPA Tier 3, making it an environmentally responsible choice for marine applications.

4. Robust Construction

The engine block is made from high-strength cast iron, ensuring durability and longevity under harsh marine conditions. Precision machining and quality components reduce wear and extend service intervals.

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Performance and Power Delivery

The Yanmar 4LV170 (Z) delivers 170 horsepower at 3,300 RPM, providing ample thrust for medium-sized vessels. This power level makes it ideal for:

• Cruising sailboats requiring auxiliary power

• Commercial fishing boats that need reliable, sustained output

• Trawlers and coastal patrol boats demanding robust, consistent propulsion

Its torque curve is designed to provide high torque at low and mid-range RPMs, which is critical for marine applications where propeller efficiency and maneuverability at various speeds matter.

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Benefits of the Yanmar 4LV170 (Z) Diesel Engine

Owning a Yanmar 4LV170 (Z) brings several advantages, especially for those serious about reliability, fuel economy, and ease of maintenance:

1. Fuel Efficiency

The CRDI system combined with turbocharging ensures excellent fuel burn, reducing operating costs — a key consideration for commercial operators and long-distance cruisers alike.

2. Compact and Lightweight

Despite delivering 170 HP, the engine’s compact size and relatively light weight (around 430 kg) make it easier to install in smaller engine compartments without sacrificing performance.

3. Low Emissions and Noise

Meeting IMO Tier II and EPA Tier 3 standards, this engine helps vessel owners meet environmental regulations. Additionally, its smooth running and reduced noise improve onboard comfort.

4. Easy Maintenance

Yanmar’s global network ensures the availability of spare parts and skilled service technicians. The engine’s design emphasizes ease of access to components, making routine checks and servicing straightforward.

5. Proven Reliability

Yanmar engines have a long-standing reputation for reliability in tough marine environments, and the 4LV170 (Z) is no exception. Its robust design withstands saltwater exposure, vibration, and long operational hours.

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Applications: What Boats Use the Yanmar 4LV170 (Z)?

The 170HP power rating fits a wide range of marine vessels, including but not limited to:

• Sailboats and Cruisers: Perfect as auxiliary power for sailing yachts needing dependable, fuel-efficient engines for docking and calm water motoring.

• Fishing Boats: Small to medium commercial fishing boats use the 4LV170 (Z) for its durability and steady power delivery.

• Trawlers and Workboats: Ideal for trawlers and coastal workboats requiring reliable diesel power to operate in varying sea conditions.

• Patrol and Rescue Boats: Its quick throttle response and reliable torque make it suitable for patrol and rescue vessels requiring agility and endurance.

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Installation and Integration

Yanmar offers detailed installation manuals and kits to simplify the integration of the 4LV170 (Z) into your vessel. Features like standard SAE mounting dimensions and flexible shaft alignments allow easy compatibility with common marine transmissions.

Many boatyards and marine engineers prefer the Yanmar 4LV170 (Z) due to:

• Standardized mounting points

• Compatibility with popular marine gearboxes (ZF, PRM)

• Integrated fresh and seawater cooling options

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Maintenance and Care Tips for Yanmar 4LV170 (Z)

To ensure your Yanmar 4LV170 (Z) engine runs optimally for years, regular maintenance is essential:

1. Regular Oil and Filter Changes

Use high-quality marine diesel oil and change oil filters according to the manufacturer’s recommended intervals, typically every 200-250 operating hours.

2. Fuel System Maintenance

Monitor and replace fuel filters frequently to avoid clogging from contaminants. Periodically check the CRDI injectors for performance.

3. Cooling System Checks

Ensure the freshwater coolant is topped up and the seawater pump impeller is in good condition to prevent overheating.

4. Belt and Hose Inspection

Check belts for tension and wear, and inspect hoses for leaks or cracks to avoid unexpected breakdowns.

5. Battery and Electrical System

Ensure the 12V electrical system is in good condition, with clean battery terminals and proper starter function.

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Troubleshooting Common Issues

Though reliable, some common issues owners might face with the 4LV170 (Z) include:

• Hard Starting: Often caused by low battery voltage or clogged fuel filters.

• Overheating: Usually linked to blocked seawater intake or failed impeller.

• Excessive Smoke: May result from injector wear or air in the fuel system.

• Loss of Power: Could be due to turbocharger faults or clogged air filters.

Following proper maintenance schedules and addressing these problems early can extend the engine’s lifespan and improve performance.

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Where to Buy Yanmar 4LV170 (Z) Engines and Spare Parts

Yanmar maintains an extensive global dealer network, making it easy to source genuine parts and engines. Authorized dealers provide warranty support and expert installation guidance. Popular online marine parts distributors and brokers also list the 4LV170 (Z) as a reliable option for replacement or new installations.

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Comparison with Similar Marine Diesel Engines

The Yanmar 4LV170 (Z) competes with other 4-cylinder marine diesel engines such as:

• Volvo Penta D4-170: Comparable horsepower and similar features but typically heavier.

• Cummins QSB 4.5: Offers more displacement but at a higher weight and cost.

• John Deere 4045: Robust, but less fuel efficient and bulkier.

Yanmar’s balance of lightweight design, modern emission compliance, and fuel economy often gives it an edge in the medium HP category.

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Summary: Why Choose the Yanmar 4LV170 (Z)?

The Yanmar 4LV170 (Z) 170HP Inboard Diesel Engine is a smart choice for marine vessels needing reliable, efficient, and environmentally conscious propulsion. Its advanced fuel injection system, turbocharging, and compact design make it suitable for a wide variety of boats from recreational yachts to commercial fishing vessels.

If you prioritize:

• Fuel efficiency and lower emissions

• Proven reliability and durability

• Strong global service and parts network

• Smooth, quiet operation

• Compliance with modern environmental standards

Then the Yanmar 4LV170 (Z) stands as a leading option in its class.