Yanmar 6LY400 – Marine Diesel Engine 400 HP

Description

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).

Key Specifications of the Yanmar 6LY400 Marine Diesel Engine

• The 5.813-liter 6-cylinder diesel block produces 400 horsepower at 3300 RPM, providing steady cruise speeds for planing hull designs.
• Common-rail fuel delivery optimizes injection timing, resulting in smooth combustion, low engine vibration, and clean transom exhaust output.
• Water-cooled intercooled turbocharging maximizes intake air volume, enabling prompt acceleration onto plane under heavy vessel load conditions.
• Freshwater heat exchanger thermal management isolates internal block passages from raw seawater, preventing internal scale and metal pitting.
• An onboard 12V 125-amp alternator delivers continuous charging power to keep start batteries and bridge navigation screens fully energized.
• An SAE 3 flywheel housing supports straightforward coupling to KMH61A down-angle and KMH61V V-drive hydraulic marine gears.

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.

Mounting and Compensation Considerations

Check stringer rail spacing and mount drop height to ensure proper shaft coupling alignment. Confirm raw water intake scoop capacity and check that wet exhaust risers maintain adequate clearance above the waterline.

Warranty and Support

Yanmar protects this propulsion package with a 2-Year Limited Recreational Warranty covering major engine assembly 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 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.