Yanmar 6LY3-STP – Inboard Diesel Engine 440 HP

Yanmar 6LY3-STP 440 HP – High-Output Yacht Propulsion Engine

Overcoming the weight-to-power limitations of mid-sized cruisers, the Yanmar 6LY3-STP delivers a potent 440 HP at 3300 RPM. This engine is specifically engineered for the American recreational yacht market, offering a high-performance in-line 6-cylinder configuration that minimizes vibration and enhances passenger comfort. The sophisticated turbocharging system provides the high-end speed required for long-distance cruising across the Florida Strait or the Pacific Northwest Sounds with exceptional reliability.

Ensuring full compliance with USA EPA Tier 3 mandates, the 6LY3-STP utilizes advanced common-rail technology to eliminate the soot and odor typically found in older diesel generations. This clean-burning performance is paired with Yanmar’s E-Controls, providing American yacht owners with digital throttle precision and integrated vessel management capabilities. The oversized heat exchanger and high-efficiency cooling system are built to handle high-ambient temperatures in tropical US waters, maintaining peak performance under load.

Core Technical Specifications

• Maximum Output: 440 HP at 3300 RPM.
• Displacement: 354 cubic inches (5.813 Liters).
• Configuration: 6-cylinder, 4-stroke, vertical diesel.
• Aspiration: Turbocharged with charge air cooler.
• Dry Weight: Approximately 1411 lbs with KMH61A gear.
• Electrical: 12V / 80A marine alternator.
• Compliance: EPA Tier 3 and RCD2 certified.
• Fuel Injection: High-pressure common rail.