Yanmar 6LY400 – Marine Diesel Engine 400 HP

Pushing 400 horsepower at 3300 RPM from a 5.813-liter displacement block, the Yanmar 6LY400 offers an efficient power solution for mid-sized sportfishers and express cruisers. High-pressure common-rail fuel injection provides refined fuel atomization, minimizing engine noise at idle and reducing fuel burn during long offshore passages. Turbocharged and intercooled air induction ensures quick throttle response when maneuvering in rough waters.

Closed freshwater heat exchanger cooling protects internal iron waterways from raw seawater corrosion. The bobtail engine setup features an SAE 3 flywheel housing, a 12V 125-amp charging alternator, VC10 electronic controls, and a dry mass of 585 kg (1290 lbs).

Helm Use and Readability

Inline 6-cylinder mechanical balance and electronic fuel metering create a quiet cabin environment with this Yanmar inboard engine. Pressure lubrication with a 19-liter oil sump protects main bearings under heavy continuous operation, while VC10 controls provide digital gear shifting.

Why Choose the Yanmar 6LY400 Marine Diesel Engine

Vessel owners select the 6LY400 marine engine for its compact 5.813-liter block and responsive 400 horsepower rating. Common-rail fuel delivery and intercooled turbocharging provide clean, smoke-free operation. With an SAE 3 housing, 125-amp alternator, and light 585 kg weight, it represents a modern repower choice.

Warranty and Support

Yanmar protects this propulsion package with a 2-Year Limited Recreational Warranty covering major engine assembly 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 6LY400 Marine Diesel Engine

Measure your engine room length, width, and height clearance to verify fitting space for an inline 6-cylinder block. Check your transmission drop angle, shaft coupling flange size, and fuel line diameters before completing your purchase.