Yanmar 6LF550 – Inboard Diesel Engine 550 HP

Description

Large express yachts and commercial vessels requiring high torque output can rely on the Yanmar 6LF550. This heavy-duty 6.7-liter inline 6-cylinder marine diesel engine generates 550 horsepower at 3000 RPM. High-pressure common-rail fuel injection delivers precise, multi-stage fuel atomization, resulting in clean combustion, low engine noise, and exceptional fuel efficiency during continuous high-load cruising.

Closed freshwater heat exchanger cooling isolates the 6.7-liter cylinder block from raw seawater corrosion. Built on an SAE 3 flywheel housing, it includes a 12V 120-amp alternator, VC20 electronic controls, a 28-liter coolant capacity, and a dry weight of 780 kg (1720 lbs).

Key Specifications of the Yanmar 6LF550 Inboard Marine Engine

• The heavy-duty 6.7-liter 6-cylinder engine produces 550 horsepower at 3000 RPM, delivering heavy propulsive thrust for large planing hulls.
• Common-rail direct fuel injection optimizes atomization inside the combustion chamber, significantly reducing mechanical vibration, noise, and soot emissions.
• Turbocharged and intercooled air induction maximizes air charge density, ensuring prompt throttle response when accelerating heavy vessels.
• Freshwater heat exchanger thermal management keeps internal waterways isolated from raw seawater, preventing scale accumulation and metal pitting.
• An onboard 12V 120-amp alternator supplies high-capacity charging output to support house battery banks and modern electronics suites.
• The standard SAE 3 flywheel housing pairs seamlessly with KMH61A hydraulic marine gears and compatible ZF transmission assemblies.

Helm Use and Readability

Large 6.7-liter displacement combined with common-rail technology creates an extraordinarily smooth power source in this Yanmar inboard engine. Pressure lubrication with a 25-liter oil capacity protects internal bearings, while VC20 digital controls provide advanced vessel management.

Why Choose the Yanmar 6LF550 Inboard Marine Engine

Captains choose the 6LF550 marine engine for its massive 6.7-liter displacement block and top-tier 550 horsepower rating. Common-rail fuel injection and intercooled turbocharging provide rapid planing performance without smoke. Closed freshwater cooling, SAE 3 housing compatibility, and VC20 digital controls make it a premier choice for commercial and luxury repowers.

Mounting and Compensation Considerations

Verify engine room floor space and stringer structural reinforcement to accommodate a 780 kg engine mass. Ensure raw water sea strainers and exhaust riser piping meet the high cooling flow demands of a 550 horsepower engine.

Warranty and Support

Yanmar protects this high-output engine with a 2-Year Factory Limited Warranty covering major internal mechanical components. Mulmarine.com can assist with technical product details and freight delivery questions before purchase. The engine order is verified for visible package and documented accessory completeness before freight dispatch. Please review the warranty coverage and eligibility details on Mulmarine.com before purchase.

Before Ordering the Yanmar 6LF550 Inboard Marine Engine

Measure your engine compartment hatch access and height clearance for a 6.7-liter inline 6-cylinder block. Confirm your hydraulic transmission gear ratio, shaft coupling bolt pattern, and battery cable sizes before finalizing your order.