Yanmar 6LY440 – Marine Diesel Engine 440 HP

Delivering 440 horsepower at 3300 RPM directly to your vessel drive system is straightforward with the Yanmar 6LY440. This 5.813-liter inline 6-cylinder diesel motor utilizes high-pressure common-rail fuel injection, offering smooth combustion and responsive mid-range acceleration for sportfishing boats and fast planing cruisers. An integrated turbocharged and intercooled air system optimizes intake density while keeping exhaust emissions exceptionally clean.

Thermal control relies on a closed freshwater heat exchanger loop that isolates internal cylinder waterways from raw seawater. Operating with an SAE 3 flywheel housing, the engine features a 12V 125-amp alternator, VC10 electronic vessel controls, and a compact dry weight of 585 kg (1290 lbs) without marine gear.

Helm Use and Readability

Smooth engine balancing and electronic throttle management define the operational feel of this Yanmar inboard engine. The inline 6-cylinder firing order minimizes hull vibration, while VC10 electronic vessel control integration outputs real-time engine health data directly to bridge screens.

Why Choose the Yanmar 6LY440 Marine Diesel Engine

Captains select the 6LY440 marine engine for its light 585 kg dry weight and potent 440 horsepower output. Its 5.813-liter common-rail architecture delivers fast planing performance without typical mechanical diesel exhaust smoke. The combination of an SAE 3 flywheel housing, 125-amp alternator, and VC10 digital controls makes it a top-tier repower selection.

Warranty and Support

Yanmar backs this engine with a 2-Year Limited Recreational Warranty covering major internal mechanical components against manufacturing defects. provides product-information support before purchase and assistance with order-related questions. Prior to freight shipment, staff verify the crated engine package against the confirmed order details. Review warranty eligibility and current coverage details on before placing your order.

Before Ordering the Yanmar 6LY440 Marine Diesel Engine

Measure your engine compartment hatch dimensions to confirm fitting clearance for a 5.813-liter inline 6-cylinder block. Confirm your transmission gear ratio, propeller shaft coupling bolt layout, and battery cable sizing before finalizing your order.