Yanmar 6LF550 – Inboard Diesel Engine 550 HP

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).

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.

Warranty and Support

Yanmar protects this high-output engine with a 2-Year Factory Limited Warranty covering major internal mechanical components. 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 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.