Yanmar 6LY400 – Marine Diesel Engine 400 HP

Yanmar 6LY400 400 HP – Advanced Common Rail Marine Propulsion

Maximizing power density in narrow engine compartments is the primary mechanical challenge solved by the Yanmar 6LY400. Delivering a formidable 400 HP at 3300 RPM, this 5.8-liter in-line 6-cylinder engine utilizes a high-pressure common-rail fuel system to provide instantaneous throttle response and reduced vibration for American offshore cruisers. Its compact footprint is specifically engineered for twin-engine installations in medium-sized sportfishing vessels where maximizing deck space is a priority for USA captains.

Adhering to strict EPA Tier 3 emission standards, the 6LY400 employs a 24-valve cylinder head and advanced electronic management to ensure smoke-free operation and superior fuel economy. For the American boater, this engine integrates seamlessly with NMEA 2000 networks, providing real-time digital diagnostics on modern helm displays. The robust freshwater cooling system is designed to withstand high-salinity conditions from the Gulf of Mexico to the Atlantic seaboard, ensuring long-term internal protection against galvanic corrosion.

Core Technical Specifications

• Maximum Output: 400 HP at 3300 RPM.
• Displacement: 354 cubic inches (5.808 Liters).
• Configuration: 6-cylinder in-line, 4-stroke diesel.
• Aspiration: Turbocharged with liquid-cooled intercooler.
• Dry Weight: Approximately 1164 lbs (engine only).
• Electrical: 12V / 125A high-output alternator.
• Compliance: Fully certified EPA Tier 3 standards.
• Bore and Stroke: 4.17 x 4.33 inches.