Yanmar 6AYM-STE 659HP Marine Diesel Engine
The Yanmar 6AYM-STE 659HP Marine Diesel Engine is a powerful six-cylinder inboard diesel engine engineered for commercial fishing vessels, workboats, passenger vessels, and demanding marine repowering applications.
Producing 659 metric HP (485 kW) at 1,900 RPM, the 6AYM-STE combines a 20.379-litre displacement with turbocharging, intercooling, and direct diesel injection.
Designed for demanding commercial marine service, the engine delivers substantial torque, durable construction, and dependable propulsion performance.
Why Choose the Yanmar 6AYM-STE?
Powerful 659 HP Commercial Performance
The Yanmar 6AYM-STE delivers 485 kW at 1,900 RPM, providing substantial propulsion power for appropriately matched commercial vessels.
Turbocharged and Intercooled Design
The turbocharger and intercooler support efficient combustion, strong torque delivery, and effective engine performance under load.
Proven Direct-Injection Technology
The engine uses direct diesel injection, offering reliable fuel delivery and conventional marine diesel operation.
Heavy-Duty Marine Construction
Its large-displacement inline-six design, heat-exchanger cooling, and compatible hydraulic marine gearboxes make it suitable for demanding shaft-drive installations.
Technical Specifications
| Specification | Details |
|---|---|
| Manufacturer | Yanmar |
| Engine Model | 6AYM-STE |
| Engine Series | 6AY |
| Engine Type | Four-stroke marine diesel |
| Configuration | Inline six-cylinder |
| Displacement | 20.379 litres |
| Rated Power | 659 metric HP / 485 kW |
| Rated Engine Speed | 1,900 RPM |
| Published Duty Rating | H-rating |
| Bore × Stroke | 155 × 180 mm |
| Fuel Injection | Direct injection |
| Aspiration | Turbocharged and intercooled |
| Cooling System | Freshwater cooling with heat exchanger |
| Starting System | 24V electric starter |
| Starter Motor | 7.0 kW |
| Flywheel Housing | SAE No. 0 |
| Flywheel Diameter | 18 inches |
| Dry Engine Weight | Approximately 2,365 kg without gearbox |
| Reference Engine Dimensions | 2,000 × 1,305 × 1,431 mm |
| Compatible Marine Gearboxes | YX-181, YX-180L, YXH-240L |
| Propulsion | Conventional inboard shaft drive |
| Applications | Commercial fishing, workboats and passenger vessels |
Specifications refer to published historical Yanmar 6AYM-STE technical documentation. Exact configuration, installed equipment, and applicable approvals must be verified against the engine identification plate.
Compatible Marine Gearboxes and Controls
The Yanmar 6AYM-STE supports selected heavy-duty hydraulic marine transmissions.
| Marine Gearbox | Published Reduction Ratios |
|---|---|
| Yanmar YX-181 | 2.08:1 / 2.55:1 / 3.03:1 |
| Yanmar YX-180L | 3.50:1 / 4.00:1 / 4.54:1 |
| Yanmar YXH-240L | 4.89:1 / 5.36:1 / 5.91:1 / 6.57:1 / 6.95:1 |
These transmissions use hydraulic multi-disc clutches. The correct reduction ratio must be selected according to the vessel’s displacement, propeller requirements, and operating conditions.
Compatible Control Equipment
Depending on the engine configuration, suitable equipment may include:
- Mechanical throttle and shift controls
- Marine engine instrument panels
- Engine temperature and oil-pressure monitoring
- Engine warning and protection systems
- Compatible wiring harnesses
- Remote-control heads and cables
- Marine shaft couplings and installation accessories
Applications and Duty Rating
The Yanmar 6AYM-STE is designed for commercial marine applications such as:
- Commercial fishing and trawling vessels
- Workboats and utility vessels
- Passenger and transport boats
- Commercial displacement vessels
- Compatible heavy-duty marine repowering projects
The historical Yanmar technical guide identifies the 6AYM-STE 659 HP as an H-rated engine.
Its suitability for extended operation depends on the manufacturer’s applicable duty-rating definitions, vessel loading, cooling capacity, and maintenance requirements.
Price, Package Contents and Warranty
Price: Contact JB Marine GmbH for a quotation.
Depending on the selected configuration, the package may include:
- Yanmar 6AYM-STE marine diesel engine
- Turbocharger and intercooling components
- Freshwater cooling system
- Electric starter motor
- Compatible hydraulic marine gearbox
- Engine instrument panel
- Selected wiring and installation accessories
The gearbox, alternator, shaft coupling, exhaust components, engine mounts, and other accessories must be specifically confirmed in the quotation.
Warranty: Applicable manufacturer or seller warranty coverage depends on the engine’s condition, production year, market, and supply arrangement. Full terms will be confirmed before purchase.
Frequently Asked Questions
How Much Power Does the Yanmar 6AYM-STE Produce?
The engine produces 659 metric HP (485 kW) at 1,900 RPM.
What Is the Displacement of the Yanmar 6AYM-STE?
The engine has a displacement of 20.379 litres.
Is the Yanmar 6AYM-STE Turbocharged?
Yes. It uses turbocharging and intercooling.
Which Marine Gearboxes Are Compatible?
Published transmission options include the Yanmar YX-181, YX-180L, and YXH-240L.
Is the Yanmar 6AYM-STE Suitable for Commercial Fishing Vessels?
Yes. It is designed for compatible commercial marine applications, including fishing vessels and workboats.
Is the Yanmar 6AYM-STE Suitable for Repowering?
Yes. It may be suitable for commercial repowering projects, provided the engine dimensions, mounting system, gearbox, propeller, shafting, cooling, and exhaust arrangements are compatible.
Buy the Yanmar 6AYM-STE 659HP from JB Marine GmbH
Looking for a Yanmar 6AYM-STE 659HP marine diesel engine for sale?
JB Marine GmbH provides quotations for Yanmar commercial marine diesel engines, compatible heavy-duty marine gearboxes, propulsion accessories, and international shipping.
Contact our sales team with your vessel specifications, preferred gearbox ratio, required quantity, and delivery destination.
Request your Yanmar 6AYM-STE 659HP quotation today.
Website: https://jbmarinegmbh.de/
