Yanmar 4JH80 – Marine Diesel Engine 80 HP

Description

Engine compartments requiring extremely tight physical mounting clearances can safely accommodate the Yanmar 4JH80. This 1.995-liter in-line 4 marine diesel pushes 80 horsepower at a governed 3200 RPM consistently. A high-pressure common-rail injection system completely eliminates heavy mechanical idle clatter. Forced enclosed lubrication utilizes a 5.0-liter oil sump. This actively protects moving components across varying dynamic operational loads in rough water. The dedicated turbocharger maximizes combustion oxygen density. It maintains highly responsive throttle performance across mid-range operating speeds without requiring complex external air management setups.

Protecting the internal architecture, a closed freshwater heat exchanger system regulates internal block temperatures using a 7.2-liter coolant capacity. Raw seawater stays entirely outside the engine cylinder waterways. This prevents internal salt scaling and related metal corrosion permanently. For electrical demands, an integrated 12V 125-amp alternator supplies high continuous charging current. It replenishes heavy house battery banks efficiently during long sails. The native SAE 4 flywheel housing mounts effortlessly to KM4A2 gears. A dry weight of just 229 kg minimizes the overall propulsion load affecting sailing balance.

Key Specifications of the Yanmar 4JH80 Inboard Diesel Engine

• The 1.995-liter 4-cylinder engine produces 80 horsepower at 3200 RPM, delivering steady rotational power for mid-sized sailing hulls.
• Common-rail direct injection manages fuel delivery pressure electronically, heavily suppressing mechanical operating noise and visible exhaust smoke output.
• A dedicated turbocharger maximizes combustion oxygen density, maintaining sharp throttle response curves across varying 1-3-4-2 firing order cycles.
• Closed freshwater heat exchanger cooling protects internal block passages from raw seawater, halting internal mineral scaling and rust damage.
• The native 12V 125-amp alternator pushes continuous electrical current to properly maintain heavy house batteries and critical bridge electronics.
• An SAE 4 flywheel housing allows straightforward coupling to KM4A2 mechanical gears, ZF30M hydraulic units, or SD60 saildrives.

Engine Operation and Output

Regulated by an advanced ECU, this Yanmar inboard engine delivers excellent power density within a tight physical dimensional profile. An enclosed forced lubrication circuit pumps oil through a 5.0-liter sump during demanding operational runs. The high-pressure common-rail setup satisfies stringent EPA Tier 3, RCD II, and BSO II emissions limits effectively. This happens by continuously adjusting injection timing based on exact load parameters. Throttle inputs communicate directly through the electronic control system. This completely bypasses traditional mechanical push-pull cable friction issues during demanding marina docking maneuvers.

Why Choose the Yanmar 4JH80 Inboard Diesel Engine

Cruising sailors select the 4JH80 marine diesel engine for its compact 1.995-liter configuration and dependable 80 horsepower output. Electronic common-rail injection provides incredibly clean running conditions compared to older mechanically governed units. Featuring a massive 125-amp alternator, it easily runs large DC refrigeration compressors or navigation screens. The SAE 4 flywheel housing adapts immediately to ZF30M transmissions or SD60 saildrive legs. Total dry weight stays at 229 kg. This heavily avoids drastically shifting your sailing vessel’s center of gravity after final heavy installation.

Installation and Alignment Considerations

Verify your fiberglass engine bed stringers closely to determine precise 229 kg mount positioning accurately. You must align the transmission output flange to the propeller shaft within strict factory tolerances. Ensure your raw water sea strainers and wet exhaust piping comply with the exact flow parameters required for an 80 horsepower block. The wet type mixing elbow requires a specific vertical drop measurement. This actively prevents backward seawater flooding into the 1.995-liter exhaust manifold following immediate engine shutdown sequences while cruising far offshore under sail.

Warranty and Support

This 1.995-liter propulsion block carries a standard Limited Factory Warranty covering major internal assembly defects from Yanmar directly. Mulmarine.com 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 Mulmarine.com before placing your final heavy freight purchase order confidently.

Before Ordering the Yanmar 4JH80 Inboard Diesel Engine

Gauge your engine room hatch opening carefully to confirm adequate fitting clearance for this 229 kg block. You must verify your intended transmission reduction gear ratio and existing shaft coupling layout. Check that your onboard DC wiring system safely supports a 12V 125-amp alternator charging circuit output. Next, confirm whether your helm station supports native 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 actively during operation.