Description

Yanmar 2QM15 Marine Inboard Diesel Engine 15HP

The Yanmar 2QM15 Marine Inboard Diesel Engine 15HP is a proven two-cylinder propulsion engine designed for traditional sailing yachts, displacement boats, and other compact vessels requiring dependable auxiliary diesel power.

Originally introduced during the late 1970s and commonly installed in cruising sailboats from that period, the 2QM15 earned a strong reputation for its simple mechanical construction, low-speed operating character, and practical serviceability. The engine delivers a one-hour rating of approximately 15HP at 3,000 rpm, with a continuous rating of approximately 14HP at the same engine speed.

For owners restoring an older yacht, replacing a damaged engine, or maintaining an existing propulsion arrangement, a properly inspected or professionally reconditioned Yanmar 2QM15 marine diesel engine can provide a practical solution without requiring the vessel to be completely redesigned around a newer high-speed engine.

At Yanmar Marine Experts, each available engine is reviewed according to its stated condition, configuration, gearbox arrangement, service history, and intended installation before a quotation is prepared.

Yanmar 2QM15 Engine Overview

The Yanmar 2QM15 is a naturally aspirated, vertical, four-cycle, water-cooled diesel engine using a precombustion-type combustion system. Its two-cylinder configuration and mechanically controlled fuel system provide a straightforward design that experienced marine technicians can inspect, service, and rebuild without relying on modern electronic engine-management systems.

The engine is particularly associated with sailing yachts and displacement vessels where reliability, compact installation, and predictable low-speed power are more important than high-output performance.

Unlike many newer lightweight marine diesels that operate at higher rated speeds, the 2QM15 produces its rated output at approximately 3,000 rpm. This gives the engine the slower-running character many owners of classic cruising boats prefer.

Key Features of the Yanmar 2QM15

Proven Two-Cylinder Diesel Design

The Yanmar 2QM15 two-cylinder marine engine uses a simple inline configuration designed for dependable auxiliary propulsion. Its mechanical layout makes routine inspection and troubleshooting relatively direct for technicians familiar with older Yanmar QM-series engines.

Naturally Aspirated Performance

The engine does not depend on a turbocharger or electronic common-rail system. Its naturally aspirated design reduces system complexity and makes it suitable for owners looking for a traditional mechanically governed marine diesel.

Mechanical Fuel Injection

The mechanically controlled injection arrangement provides dependable fuel delivery without electronic sensors, engine-control modules, or computerized diagnostic systems.

This simplicity can be valuable on older vessels operating in locations where access to advanced diagnostic equipment may be limited.

Water-Cooled Marine Configuration

The engine was designed specifically for marine service and uses a water-cooled arrangement. The exact cooling configuration, raw-water components, exhaust elbow, and heat-exchange arrangement should be confirmed for the individual engine being offered.

Suitable for Classic Yacht Repower Projects

The 2QM15 is often considered by owners who want to retain the original propulsion layout of a classic sailboat. It can be particularly useful where the engine beds, shaft line, propeller, exhaust system, and gearbox arrangement were originally designed around a QM-series engine.

Technical Specifications

Published legacy specifications identify the 2QM15 as a 0.662-litre engine with a 75 mm bore and 75 mm stroke. Because these engines are now normally supplied as used, rebuilt, or reconditioned units, the identification plate and actual engine configuration should be checked before purchase.

Suitable Vessel Applications

The Yanmar 2QM15 15HP inboard diesel engine may be suitable for:

• Classic sailing yachts
• Coastal cruising sailboats
• Displacement boats
• Small motor sailers
• Traditional shaft-drive vessels
• Yacht restoration projects
• Direct replacement of an existing 2QM15
• Repower projects where the original installation geometry is retained

Examples of vessels historically fitted with the 2QM15 include approximately 30-foot cruising sailboats such as the Bristol 29.9, Bristol 30, C&C 30, Hunter models, and similar displacement yachts. Actual suitability must always be determined from vessel displacement, hull resistance, gearbox ratio, shaft arrangement, and propeller calculations.

Marine Gearbox and Shaft Compatibility

The gearbox supplied with a Yanmar 2QM15 can vary between engines. Before ordering, confirm:

• Gearbox manufacturer and model
• Forward and reverse operation
• Reduction ratio
• Output-flange dimensions
• Propeller-shaft diameter
• Shaft rotation
• Control-cable arrangement
• Gearbox oil condition
• Mounting-foot configuration

A replacement engine should never be selected based only on horsepower. The gearbox ratio and propeller must allow the engine to reach its rated loaded operating speed.

Where an existing gearbox is being reused, the bellhousing, input arrangement, mounts, coupling, and alignment requirements must be checked before installation.

Engine Condition and Inspection

Because the Yanmar 2QM15 is a legacy model, engines currently available are normally supplied in one of the following conditions:

• Used take-out
• Running take-out
• Workshop inspected
• Serviced
• Reconditioned
• Fully rebuilt

The exact condition must be stated in the quotation or sales agreement.

Depending on the unit, inspection may include:

• Visual condition assessment
• Engine identification check
• Oil and coolant inspection
• Starting test
• Running test
• Oil-pressure check
• Cooling-system inspection
• Fuel-system inspection
• Smoke observation
• Compression or cylinder-condition assessment
• Gearbox engagement test
• Leak inspection

A rebuilt engine should also have a clear description of the work completed and the principal internal components replaced or renewed.

Standard Package and Available Components

The supplied package depends on the engine currently available. It may include:

• Yanmar 2QM15 base engine
• Marine reversing gearbox
• Starter motor
• Alternator
• Fuel-injection system
• Raw-water pump
• Exhaust mixing elbow
• Flexible engine mounts
• Flywheel and bellhousing
• Mechanical stop control
• Instrument panel
• Wiring harness
• Throttle and shift controls
• Operator or workshop documentation

Buyers should request written confirmation of every included component before payment. Items not specifically listed in the quotation should not be assumed to form part of the package.

Installation Considerations

Before purchasing a Yanmar 2QM15 replacement engine, compare the proposed unit with the vessel’s existing installation.

Important checks include:

• Engine-bed width and spacing
• Mounting-centre dimensions
• Shaft centerline
• Gearbox-output height
• Engine inclination
• Coupling dimensions
• Exhaust-hose diameter
• Raw-water intake size
• Fuel supply and return arrangement
• Battery voltage
• Control-cable travel
• Instrument-panel compatibility
• Space for routine maintenance

The propeller shaft and coupling should be inspected before alignment. Worn bearings, a bent shaft, damaged coupling faces, or deteriorated mounts can create vibration even when the replacement engine itself is operating correctly.

Final engine alignment should be completed according to the marine gearbox, coupling, shafting, and installation requirements for the vessel.

Maintenance and Parts Support

Routine maintenance is essential for keeping an older Yanmar QM-series engine dependable.

Typical service areas include:

• Engine oil and filter
• Fuel filters
• Raw-water pump impeller
• Cooling passages
• Thermostat
• Drive belts
• Fuel injectors
• Injection pump
• Valve clearances
• Exhaust mixing elbow
• Engine mounts
• Gearbox oil
• Shaft alignment

The original 2QM15 operation and workshop documentation includes engine specifications, installation guidance, operating procedures, electrical information, regular maintenance, troubleshooting, disassembly, and servicing instructions.

Parts availability should be confirmed by serial number because production changes and previous repairs may affect component compatibility.

Why Buy From Yanmar Marine Experts?

At Yanmar Marine Experts, we help customers evaluate more than the engine model printed on the identification plate.

Before preparing an offer, we can review:

• Vessel type
• Existing engine and gearbox
• Engine condition required
• Gearbox ratio
• Shaft and coupling arrangement
• Required accessories
• Delivery location
• Installation schedule
• Inspection requirements

Our goal is to provide a clearly described package so the buyer understands the engine’s condition, included components, exclusions, delivery terms, and installation requirements before proceeding.

Availability, Delivery and Warranty

Availability of the Yanmar 2QM15 is subject to current used, rebuilt, or reconditioned inventory.

Delivery can be arranged according to the customer’s location and preferred shipping method. The engine can be prepared for domestic or international transport using suitable protective packing.

Warranty coverage depends on the condition of the engine and the terms stated in the final quotation. A used engine, inspected running take-out, and fully rebuilt engine may each carry different warranty conditions.

Always review the written warranty, installation obligations, commissioning requirements, and exclusions before purchase.

Request a Quote for the Yanmar 2QM15

Contact Yanmar Marine Experts for current availability of the Yanmar 2QM15 Marine Inboard Diesel Engine 15HP.

To receive an accurate quotation, provide:

• Vessel make and model
• Current engine model
• Existing gearbox and ratio
• Propeller-shaft arrangement
• Required engine condition
• Components needed
• Delivery city and country
• Target installation date

We will confirm the available engine, package configuration, condition, price, shipping options, and estimated delivery schedule.

Frequently Asked Questions

Is the Yanmar 2QM15 still manufactured?

No. The 2QM15 is a legacy Yanmar model originally used in vessels from the late 1970s and early 1980s. Units available today are generally used, inspected, reconditioned, or rebuilt engines.

How much power does the Yanmar 2QM15 produce?

The engine is commonly listed with a one-hour rating of approximately 15HP at 3,000 rpm and a continuous rating of approximately 14HP at 3,000 rpm.

Is the Yanmar 2QM15 suitable for a sailboat?

Yes. It was widely used as an auxiliary inboard diesel engine in classic cruising sailboats and displacement yachts. Suitability for a particular vessel must still be confirmed using displacement, gearbox ratio, shaft, and propeller information.

Can I replace my existing 2QM15 directly?

A direct replacement may be possible when the gearbox, mounts, engine beds, shaft alignment, exhaust, cooling, controls, and electrical system remain compatible. Every installation should be measured and inspected before the replacement engine is ordered.

Is a gearbox included?

That depends on the available engine package. Some engines may be offered bobtail, while others include a marine reversing gearbox. The quotation will state the exact gearbox model, ratio, and included components.

Are parts available for the Yanmar 2QM15?

Many service and repair parts may remain available through specialist suppliers, used-parts sources, or aftermarket manufacturers. Availability must be checked using the engine model, serial number, and exact component required.

What information is needed for a quotation?

Provide the vessel model, current engine, gearbox ratio, shaft arrangement, required accessories, preferred engine condition, delivery address, and target installation date.