Yanmar 3JH40 – Marine Diesel Engine 40 HP

Description

With 40 hp at 3,000 rpm, the Yanmar 3JH40 combines a naturally aspirated 1.642L inline three-cylinder configuration with common rail injection. The stated 17.0:1 compression ratio and EN 590 diesel requirement define its fuel-system setup. Mechanical or saildrive transmission options, KM35A2, KM35P, or SD60 drive compatibility, and electronic-control support shape the documented propulsion integration choices.

The 423-pound dry engine uses an SAE 4 flywheel housing and a 12V 125-amp alternator. Enclosed forced lubrication holds 5.0L oil, while heat-exchanger cooling uses 4.5L coolant and the wet mixing elbow forms part of the exhaust system. Listed emissions ratings include EPA Tier 3, RCD II, and BSO II.

Key Specifications of the Yanmar 3JH40 Marine Diesel Engine

• The 1.642L inline three-cylinder engine produces 40 hp at 3,000 rpm through naturally aspirated common rail diesel operation.
• Common rail injection and EN 590 fuel requirements define the documented fuel-system specification for the stated 17.0:1 compression ratio.
• Mechanical or saildrive transmission choices require propulsion planning around the SAE 4 flywheel housing and vessel layout.
• KM35A2, KM35P, and SD60 drive options define the listed propulsion interfaces for compatible repower or new-build installations.
• A 12V 125-amp alternator provides the stated charging output for vessels using this engine electrical-system configuration.
• Heat-exchanger cooling holds 4.5L coolant, while the wet mixing elbow defines the specified exhaust-water arrangement.
• Enclosed forced lubrication uses 5.0L oil capacity, supporting planned servicing within the completed engine-room installation layout.

Engine Configuration and Service Access

This Yanmar marine diesel engine uses an inline three-cylinder, four-stroke layout with 88 by 90 mm bore and stroke dimensions. The stated 1-3-2 firing order, electronic-control compatibility, and 423-pound dry weight are relevant when planning engine-bed loading, controls, and surrounding service clearance.

Common rail components, cooling connections, alternator wiring, wet-exhaust routing, lubrication-service points, and the selected mechanical or saildrive arrangement should remain accessible after installation.

Why Choose the Yanmar 3JH40 Marine Diesel Engine

The 3JH40 marine diesel engine combines 40 hp at 3,000 rpm with common rail injection in a naturally aspirated 1.642L three-cylinder layout. Buyers comparing propulsion packages can assess its 12V 125-amp alternator, electronic-control compatibility, mechanical or saildrive options, and KM35A2, KM35P, or SD60 drive configurations. Its 423-pound dry weight and EPA Tier 3 rating provide additional integration context.

Installation and Compatibility Considerations

Confirm that the vessel supports the 423-pound dry weight, SAE 4 flywheel housing, selected mechanical or saildrive transmission, and KM35A2, KM35P, or SD60 drive configuration. Plan engine mounts, shaft or saildrive alignment, fuel supply, cooling-water intake, wet-exhaust routing, electronic controls, charging wiring, ventilation, and service access before installation.

Use fuel meeting EN 590 requirements and allow access for common rail servicing, 5.0L lubrication capacity, and 4.5L cooling capacity. Verify electronic-control compatibility and follow applicable Yanmar installation, commissioning, and maintenance documentation for the completed propulsion system.

Warranty and Support

This model is eligible for Yanmar’s 3-Year Extended Limited Warranty program for first retail purchasers, subject to private and recreational use requirements. Mulmarine.com provides product-information support before purchase and assistance with order-related questions. Review warranty eligibility and current coverage details on Mulmarine.com before placing your order.

Before Ordering the Yanmar 3JH40 Marine Diesel Engine

Before ordering, verify engine-bed dimensions, mount locations, SAE 4 flywheel-housing compatibility, selected transmission type, and the required KM35A2, KM35P, or SD60 drive arrangement. Confirm the vessel has EN 590 diesel fuel supply, cooling-water and wet-exhaust systems, compatible electronic controls, 12V wiring, ventilation, shaft or saildrive alignment, and professional installation planning.