FREE DELIVERY TODAY - 10% Discount for next 3 orders! Place your 1st order in.
Yanmar 4LHA-STP – Inboard Marine Diesel Engine 240 HP
Yanmar 4LHA-STP – 240 HP features a high-performance 4-cylinder propulsion architecture, serving as the flagship of the LHA series with 240 HP from a 3.4L block. By utilizing advanced intercooling and a performance-tuned turbocharger, this model provides the explosive acceleration and high top-end speeds required for fast interceptors and sporty recreational cruisers while maintaining a mechanical “bulletproof” design.
- Transom/Engine Integration Specification: Rated at 240 HP (177 kW) at 3300 RPM.
- Core Engine Mechanical Design: Inline 4-Cylinder 3.45L Turbo-Aftercooled.
- High Precision Fuel Induction: Mechanical Injection with Turbocharged Boost.
- Optimal Marine Vessel Compatibility: Ideal for high-speed sportboats and yacht tenders.
- Long Term Warranty Coverage: Yanmar global marine dealer support.
Products are almost sold out
available only:
3In Stock
Description
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.
Yanmar 4LHA-STP Full Specs
| Engine type | In-line 4, 4-stroke Diesel |
| Displacement | 3.455L (211 cid) |
| Bore x stroke | 100 x 110 mm |
| Horsepower | 240 hp (177 kW) |
| Rated rpm | 3300 rpm |
| Aspiration | Turbocharged & Intercooled |
| Compression ratio | 18.4:1 |
| Fuel system | Direct Injection |
| Recommended fuel | Diesel (ISO 8217 DMA) |
| Ignition/Firing Order | Compression / 1-3-4-2 |
| Alternator | 12V, 60 Amp |
| Gear ratio/Drive | HSW450A / HSW630A |
| Transmission | Hydraulic Marine Gear |
| Dry weight | 365 kg (805 lbs) |
| Flywheel housing | SAE 4 |
| Steering | Mechanical / Hydraulic compatible |
| Coolant capacity | 11.5L |
| Exhaust system | Fresh water cooled manifold |
| Cooling system | Heat Exchanger |
| Lubrication | Forced lubrication |
| Oil capacity | 11L |
| Emissions rating | IMO Tier II compliant |
Yanmar 4LHA-STP Service & Performance Guide
What is the fuel consumption of the Yanmar 4LHA-STP?
The 4LHA-STP consumes approximately 13.2 gallons per hour at its maximum 3,300 RPM. This 3.4-liter four-cylinder mechanical engine is a legendary choice for repowering mid-sized sport-fishing boats. For optimal efficiency, cruise at 2,400 RPM to maintain plane while significantly reducing hourly fuel burn and internal engine stress.
What oil grade is required for the Yanmar 4LHA-STP?
This engine requires 13.7 quarts of SAE 15W-40 oil meeting API Service Class CD or higher. Given its mechanical fuel injection, maintaining high-quality lubrication is vital for turbocharger longevity and main bearing protection. Replace the oil and the primary lube filter every 250 hours to ensure maximum operational reliability.
How does the Yanmar 4LHA-STP cooling system operate?
It features a closed-loop freshwater system with a high-capacity heat exchanger and seawater-cooled aftercooler. This design ensures stable operating temperatures for the cast-iron block even during sustained high-speed transit in tropical waters. Inspect the seawater pump impeller every 100 hours to prevent overheating and potential head gasket damage.
What are the electrical system specifications for this engine?
Standard 4LHA-STP units come with a 12V-80A alternator, providing sufficient power for basic navigation electronics and starting battery charging. This simple electrical architecture is ideal for offshore vessels where mechanical reliability is the primary concern. Periodically check all ground connections to the block to ensure steady 12V system performance.
What are the physical dimensions and weight of the 4LHA-STP?
The dry weight is 805 lbs, measuring 44.1 inches in length and 28.1 inches in width. Its compact four-cylinder footprint allows for twin-engine installations in boats with limited engine room beam. Maintain a 3-inch clearance around the intake manifold for easy access during routine fuel filter maintenance.
You must be logged in to post a review.
Reviews
There are no reviews yet.