Yanmar 4LHA-STP – Inboard Marine Diesel Engine 240 HP

Yanmar 4LHA-STP 240 HP – High-Torque Mechanical Marine Diesel

Eliminating electronic dependency in offshore environments is the primary mechanical advantage of the Yanmar 4LHA-STP. Delivering a robust 240 HP at 3300 RPM, this 4-cylinder turbocharged engine is a favorite for American boaters who prioritize mechanical reliability and ease of service in remote USA coastal waters. Its high power-to-weight ratio and compact footprint make it an ideal repower solution for classic American sportfishing boats and mid-sized cruisers seeking a durable, “bulletproof” diesel heart without complex ECU systems.

Adhering to applicable EPA emission standards for mechanical engines, the 4LHA-STP features a direct-injection system and wastegate turbocharger to provide a linear torque curve and rapid hole-shot performance. For the American operator, this translates to a dependable engine that excels in high-load scenarios, from the Florida Keys to the Pacific Northwest. The freshwater cooling system, equipped with a heavy-duty heat exchanger, ensures optimal thermal management and prevents internal galvanic corrosion in high-salinity marine environments.

Core Technical Specifications

• Maximum Output: 240 HP at 3300 RPM.
• Displacement: 212.8 cubic inches (3.489 Liters).
• Configuration: 4-cylinder in-line, 4-stroke diesel.
• Aspiration: Turbocharged with seawater intercooler.
• Dry Weight: Approximately 805 lbs (engine only).
• Fuel System: Direct injection mechanical pump.
• Electrical: 12V / 80A alternator standard.
• Bore and Stroke: 3.94 x 4.33 inches.