Yanmar 4JH3-TE Specifications
| Engine Model: Yanmar 4JH3-TE |
| Engine Type: 4-stroke inline 4-cylinder turbocharged water-cooled diesel |
| Total Displacement: 121.7 cu.in (1.99 L) |
| Rated Engine Power: 75 Hp (55.2 kW) at 3800 rpm |
| Fuel System Type: Direct injection |
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The Yanmar 4JH3-TE is a four-cylinder,
turbocharged marine diesel engine from the JH Series, serving as the
direct-injection successor to the 4JH2-TE. This engine offers better
fuel efficiency and higher power output within a similar footprint,
representing a significant advancement in auxiliary marine propulsion
technology for sailboats and small power cruisers. The “TE” designation
indicates turbocharging without an aftercooler.
Unlike the naturally aspirated 4JH3-E or the intercooled 4JH3-HTE and
4JH3-DTE variants, the TE model delivers a balanced 75 hp at 3800 RPM,
making it suitable for vessels where compact size, low weight, and
reliable power are prioritized over maximum output. The 4JH3-TE employs
Bosch distributor-type direct injection, a freshwater cooling system
with a heat exchanger, and is available with multiple marine gear
options including mechanical KM4A and hydraulic KMH4A transmissions.
The Yanmar 4JH3-TE is a four-stroke, compression-ignition marine diesel
engine. The inline four-cylinder configuration provides natural balance
without requiring a balance shaft. The engine utilizes a turbocharger
for aspiration, increasing air density and power output without
increasing displacement.
Engine Type: Vertical, 4-cycle, water-cooled diesel engine
Number of Cylinders: 4 (inline)
Displacement: 1.995 Liters (121.7 cu.in)
Bore x Stroke: 84 mm x 90 mm (3.31 in x 3.54 in)
Compression Ratio: 18.4:1 (range 18.0:1-18.4:1)
Aspiration: Turbocharged
Combustion System: Direct injection
Rotation (viewed from flywheel/stern): Counter-clockwise
Maximum Output (Crankshaft): 55.2 kW (75 hp) at 3800 RPM
Continuous Output Rating: 50.7 kW (69 hp) at 3700 RPM
Maximum Torque: 181 Nm (133.5 lb-ft) at 2200-2400 RPM
Low Idle Speed: 700 ± 25 RPM
Cruising RPM Range: 3000-3300 RPM
Governed Maximum Speed (no-load): 3900 RPM
The cylinder block on the 4JH3-TE is a cast-iron monobloc design with
integral (parent-bore) cylinder bores. The deep-skirt crankcase extends
below the crankshaft centerline for rigidity without excessive weight.
Five main bearings support the forged steel crankshaft.
Cast-in cooling water passages surround each cylinder bore to maintain
uniform operating temperature. The engine mounts are adjustable on
flexible mounts to simplify installation and reduce vibration
transmission to the hull. The oil pan is a pressed steel stamping sealed
with a gasket.
The cylinder head is a single, cross-flow cast-iron casting spanning all
four cylinders. The overhead valve (OHV) configuration uses pushrods and
rocker arms actuated by a single camshaft located within the cylinder
block. Two valves per cylinder - one intake, one exhaust - are arranged
for efficient gas exchange.
Valves per Cylinder: 2 (1 intake, 1 exhaust)
Valve Configuration: Overhead valve (OHV), pushrod-actuated
Valve Seat Inserts: Induction-hardened steel (exhaust seats)
Valve Clearance (Cold - Intake): 0.20 mm (0.008 in)
Valve Clearance (Cold - Exhaust): 0.20 mm (0.008 in)
Valve Adjustment Interval: 400 operating hours
The cylinder head gasket is a metal laminate (multi-layer steel) design.
The head is secured using a torque-to-yield procedure requiring angle
tightening.
The Yanmar 4JH3-TE employs a mechanical direct injection fuel system. A
Bosch distributor-type injection pump (VE-type) is gear-driven from the
engine. This pump design integrates a mechanical governor that maintains
stable speed under varying loads, a critical feature for marine
auxiliary engines.
Injection Pump Type: Bosch distributor type (VE pump), mechanical
Injector Type: Mechanical, multi-hole
Injection Pressure: 21.6 MPa (216 bar / 3130 psi - equivalent to 220
kg/cm2)
Injection Timing (static): 12 ± 1 degree before top dead center (BTDC)
Fuel Lift Pump: Mechanical diaphragm type
Fuel Filters: Spin-on primary filter with water separator; secondary
element on injection pump
Fuel Consumption at Maximum Output (3800 RPM): Approximately 10.6 L per
hour (2.8 gal per hour)
Fuel Grade: Diesel meeting EN 590 or ASTM D975 No. 2-D
The fuel system includes a manual hand-primer on the filter head for
bleeding air after filter changes.
The lubrication system is a forced-feed, full-flow pressure system. A
trochoid-type oil pump, driven from the crankshaft, draws oil through a
suction strainer inside the oil pan. The oil passes through a full-flow
spin-on filter and then through a water-cooled oil cooler mounted on the
engine block.
Lubrication Type: Forced feed, complete enclosed forced lubrication
Oil Pump Type: Trochoid.
Oil Capacity (including filter): 7.0 Liters (7.4 U.S. quarts); KM4A
gear: 6.9 L, KBW21 gear: 5.7 L.
Oil Pressure (idle, hot): Minimum 1.0 bar (14.5 psi)
Oil Pressure (rated speed, hot): 3.0-4.5 bar (43-65 psi).
Oil Filter: Spin-on, full-flow.
Oil Cooler: Water-cooled, tube type.
Oil Grade: API CF or higher, SAE 15W-40 (standard) or SAE 10W-30 (cold
climates).
Oil Change Interval: 250 hours or 1 year.
The cooling system is a freshwater (closed-loop) design with a heat
exchanger. An engine-driven, belt-operated centrifugal pump circulates
freshwater through the cylinder block, cylinder head, and then through a
tube-and-shell heat exchanger. Seawater, pumped by a rubber
impeller-type pump, flows through the opposite side of the heat
exchanger to remove heat from the freshwater circuit.
Cooling System Type: Fresh water cooling with heat exchanger (Indirect)
Water Pump (Freshwater): Belt-driven, centrifugal
Water Pump (Seawater): Gear-driven, rubber impeller type
Coolant Capacity (engine block only): 6.0 Liters (6.3 U.S. quarts)
Expansion Tank Capacity (subtank): 0.8 Liters (0.85 U.S. quarts)
Thermostat Opening Temperature: 71°C (160°F)
Thermostat Fully Open: 85°C (185°F)
Coolant Type: Ethylene glycol-based antifreeze with anti-corrosion
additives
The 4JH3-TE uses a 12-volt marine-rated electrical system. A high-output
alternator is standard.
System Voltage: 12 V DC (negative ground).
Alternator Output: 55 A (standard); 80 A (optional).
Starter Motor: 12 V, 1.4 kW (1.9 hp).
Glow Plug System: Operated by key-switch preheat; sheathed ceramic type.
Air Intake and Turbocharging: Air enters through a dry-type paper
element air cleaner and passes through the turbocharger compressor. The
4JH3-TE uses a turbocharger without an intercooler, distinguishing it
from the 4JH3-HTE (turbocharged and intercooled) and 4JH3-DTE variants.
A rubber silencer is fitted to reduce intake noise. Turbocharger Type:
Fixed geometry, water-cooled bearing housing. Maximum Boost Pressure:
Approximately 1.2 bar absolute (3 psi gauge).
Exhaust System: A cast-iron dry exhaust manifold routes exhaust gases to
a water-injected mixing elbow. Seawater from the cooling system mixes
with the exhaust at the elbow, cooling the gases before they exit
through a reinforced rubber hose. Exhaust Pipe Diameter (dry section):
51 mm (2.0 in). Exhaust Type: Wet exhaust.
Marine Gear Options: KBW21: Mechanical wet multiple disk clutch, 2.17:1
forward reduction, 3.06:1 reverse. Oil capacity: 1.2 L. KM4A: Mechanical
wet cone clutch with 7° down angle. Reduction ratios: 1.47, 2.14, 2.63,
3.30. Oil capacity: 1.3 L. KMH4A: Hydraulic wet multiple disk clutch
with 8° down angle. Reduction ratio: 2.04. Oil capacity: 2.0 L.
Dry Weight (Engine only): 213-229 kg (470-505 lbs)
Length with KM4A Gear: 888 mm (35.0 in)
Length with KMH4A Gear: 938 mm (36.9 in)
Length with KBW21 Gear: 906 mm (35.7 in)
Width (with standard gear): 560-581 mm (22.0-22.9 in)
Height: 635-661 mm (25.0-26.0 in)
Total Weight with KM4A Gear: 247 kg (545 lbs)
Total Weight with KMH4A Gear: 250 kg (551 lbs)
Total Weight with KBW21 Gear: 249 kg (549 lbs)
Engine Oil and Filter Change: 250 hours or 12 months
Fuel Filter Primary (water separator): 250 hours; drain water monthly
Fuel Filter Secondary: 500 hours
Seawater Pump Impeller Inspection: 200 hours
Seawater Pump Impeller Replacement: 400 hours or at signs of cracking
Valve Clearance Adjustment: 400 hours
Anode Replacement (heat exchanger): 400 hours or 1 year
Heat Exchanger Cleaning (seawater side): 2 years or 800 hours
Coolant Replacement: 2 years
Engine Mount Inspection: 400 hours
Injection Pump Timing Check: 1,000 hours (dealer service)
Injector Nozzle Replacement: 1,600 hours
Cylinder Head Bolts, Stage 1: 30 Nm (22 lb-ft)
Cylinder Head Bolts, Stage 2: 60 Nm (44 lb-ft)
Connecting Rod Bolts: 30 Nm (22 lb-ft)
Main Bearing Cap Bolts: 60 Nm (44 lb-ft)
Flywheel Bolts: 65 Nm (48 lb-ft)
Crankshaft Pulley Bolt: 135 Nm (100 lb-ft)
Injection Pump Drive Gear Nut: 45 Nm (33 lb-ft)
Injector Hold-Down Clamp Bolt: 25 Nm (18 lb-ft)
High-Pressure Fuel Line Nuts: 25 Nm (18 lb-ft)
Rocker Arm Shaft Bolts: 25 Nm (18 lb-ft)
Valve Cover Bolts: 10 Nm (89 lb-in)
Oil Pan Bolts: 12 Nm (9 lb-ft)
Oil Filter (spin-on): 15 Nm (11 lb-ft)
Exhaust Manifold Bolts: 25 Nm (18 lb-ft)
Starter Motor Mounting Bolts: 40 Nm (30 lb-ft)
Alternator Pivot Bolt: 25 Nm (18 lb-ft)
Glow Plug: 12 Nm (9 lb-ft)
Heat Exchanger Mounting Bolts: 25 Nm (18 lb-ft)
0The Yanmar 4JH3-TE is a marine propulsion engine used in sailboats and
power vessels.
Sailboats (Auxiliary Power): Vessels from 35 to 48 feet (11 to 14.5
meters) including Beneteau, Jeanneau, Hanse, Dufour, Bavaria, and
Catalina models requiring reliable auxiliary power for maneuvering and
motoring.
Small to Medium-sized Yachts: Flybridge cruisers and express cruisers up
to 40 feet (12 meters) LOA.
Fishing Vessels: Small commercial fishing boats and sportfishing
vessels.
Motor Sailers: Heavy displacement vessels requiring a balance of power
and fuel efficiency.
Downeast Boats: Semi-displacement hulls where the 75 hp output provides
efficient cruise speeds.
Charter Boats: Bareboat and crewed charter fleets where reliability and
low operating costs are essential.
Rigid Inflatable Boats (RIBs): Heavy-duty RIBs and small workboats
requiring diesel propulsion for extended range.
Catamarans: Power catamarans and sailing catamarans with one engine per
hull.
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