Yanmar 6LF485 – Inboard Diesel Engine 485 HP

Configure the propulsion of your heavy displacement vessel using the Yanmar 6LF485. This 6.7-liter in-line 6 marine diesel pushes a governed 485 horsepower at 3000 RPM. A high-pressure common-rail injection system strictly meters EN 590 diesel delivery. This eliminates intense mechanical clatter during idle maneuvering. The 17.0:1 compression ratio supports immediate cold starting under demanding maritime conditions. Turbocharged and intercooled air management forces dense oxygen into the cylinders. This setup optimizes internal combustion pressure curves across sustained heavy commercial or recreational cruising profiles without external air modification.

A closed freshwater heat exchanger system safely regulates internal block temperatures using a 28-liter coolant capacity. Raw seawater stays completely outside the internal engine cylinder waterways. This permanently prevents internal salt scaling and heavy metal corrosion. The native SAE 3 flywheel housing mounts seamlessly to KMH61A hydraulic marine gears. Auxiliary electrical systems rely on the standard 12V 120-amp alternator output. Total dry weight registers at exactly 780 kg. Repower mechanics must factor this static physical mass into the vessel’s rear hull displacement center before coupling.

Engine Operation and Output

Electronic fuel regulation provides this 6.7-liter Yanmar engine with exceptional physical power density. A massive 25-liter oil sump ensures forced pressure lubrication during demanding continuous offshore runs. The modern common-rail setup satisfies stringent EPA Tier 3, RCD II, and IMO II emissions limits. This happens by continuously manipulating fuel injection timing across the 1-5-3-6-2-4 firing order. Throttle synchronization runs directly through the digital VC20 electronic control network. This bypasses legacy mechanical push-pull cable friction issues during tight marina docking maneuvers and rapid shifting.

Why Choose the Yanmar 6LF485 Inboard Diesel Engine

Repower professionals select the 6LF485 inboard diesel engine for its substantial 6.7-liter displacement and dependable 485 horsepower output. Electronic common-rail injection provides remarkably clean running conditions compared to older mechanically governed units. Featuring a substantial 120-amp alternator, it effectively sustains large DC refrigeration compressors or navigation screens. The SAE 3 flywheel housing adapts immediately to KMH61A hydraulic transmissions or heavy ZF gears. Total dry weight remains strictly at 780 kg. This minimizes drastic center of gravity shifts inside your vessel’s main engine room.

Warranty and Support

Yanmar backs this 6.7-liter propulsion block with a standard Limited Factory Warranty covering major internal assembly defects. provides essential product-information support before purchase and technical assistance with order-related questions. A thorough pre-shipment visual inspection confirms the crated engine item and all documented included components. Mechanics and vessel owners should examine warranty coverage scope concerning specific commercial versus recreational duty cycles. Please review the detailed warranty coverage and eligibility details directly on before placing your final heavy freight purchase order.

Before Ordering the Yanmar 6LF485 Inboard Diesel Engine

Measure your engine room hatch opening carefully to confirm adequate fitting clearance for this 780 kg block. You must verify your intended transmission reduction gear ratio and existing shaft coupling dimensions. Check that your onboard DC wiring system safely supports a 12V 120-amp alternator charging circuit output. Next, confirm whether your helm station supports native VC20 electronic control inputs versus legacy mechanical push-pull cables. Ensure your existing diesel fuel filtration system matches the precise EN 590 flow demands for common-rail injection networks.