The Kubota Z402-EB is a 400 cc, (24.41 cu·in) natural aspirated two-cylinders four-stroke liquid-cooled internal combustion small diesel engine, manufactured by Kubota for general-purpose applications.
The cylinder bore is 64.0 mm (2.52 in) and the piston stroke is 62.2 mm (2.45 in). The compression ratio rating is 23.0:1.
This engine produced 8.6 PS (6.3 KW; 8.4 HP) at 3,000 rpm of net (intermittent) power and 8.8 PS (6.5 KW; 8.7 HP) at 3,000 rpm of gross (intermittent) power.
The Kubota Z402-EB features:
- Spherical type combustion chamber
- Bosch MD type mini pump
- Centrifugal ball mechanical governor
- Forced lubrication by trochoid pump
- Water cooling system with pressurized radiator
- Electric starter (12V, 1.2 kW)
General information
Engine Specifications | |
Engine model | Z402-EB |
Engine type | 4-stroke, OHV, two-cylinders |
Displacement | 400 cm3, (24.41 cu·in) |
Max. horsepower | Net (intermittent): 8.6 PS (6.3 KW; 8.4 HP) at 3,000 rpm Gross (intermittent): 8.8 PS (6.5 KW; 8.7 HP) at 3,000 rpm Gross (cont.): 7.5 PS (5.5 KW; 7.4 HP) at 3,000 rpm |
Max. torque | – |
Cooling system | Liquid-cooled with pressurized radiator |
Lubricating system | Forced lubrication by pump |
Fuel system | Bosch MD type mini pump |
Injection type | Indirect injection |
Fuel used | Diesel fuel No.2-D |
Starting system | Electric starter (12V, 1.2 kW) |
Governor | Centrifugal ball mechanical governor |
PTO shaft rotation | Counterclockwise (from PTO shaft side) |
Dimensions (L x W x H): | 314 x 380 x 449 mm (12.38 x 14.98 x 17.68 in) |
Weight: | 56 kg (123.5 Ibs) |
Cylinder Block and Head
Cylinder block | |
Compression ratio: | 23.0:1 |
Cylinder bore: | 64.0 mm (2.52 in) |
Piston stroke: | 62.2 mm (2.45 in) |
Cylinder internal diameter (standard): | 64.000-64.019 mm (2.5199-2.5204 in) |
Piston skirt outer diameter (standard): | – |
Number of piston rings (compression / oil): | 2/1 |
Piston ring side clearance (Second): | 0.085-0.112 mm (0.0033 to 0.0044 in) |
Piston ring side clearance (Oil): | 0.040-0.080 mm (0.0016 to 0.0031 in) |
Ring end gap (Top): | 0.250-0.400 mm (0.0098-0.0157 in) |
Ring end gap (Second): | 0.250-0.400 mm (0.0098-0.0157 in) |
Ring end gap (Oil): | 0.150-0.300 mm (0.0059-0.0117 in) |
Crankshaft main journal diameter: | Bearing №1,3: 39.934-39.950 mm (1.5722-1.5728 in) Bearing №2: 43.934-43.950 mm (1.7297-1.7303 in) |
Crankpin journal diameter: | 33.959-33.975 mm (1.337-1.3376 in) |
Cylinder head | |
Valve arrangement: | OHV, gear driven |
Valves: | 4 (2 valves in total) |
Valve timing (INTAKE): | Open: 20° Before T.D.C. Close: 45° After B.D.C. |
Valve timing (EXHAUST): | Open: 50° Before B.D.C. Close: 15° After T.D.C. |
Valve steam diameter (INTAKE): | 5.968-5.980 mm (0.2349 to 0.2354 in) |
Valve steam diameter (EXHAUST): | 5.968-5.980 mm (0.2349 to 0.2354 in) |
Valve seat angle (INTAKE): | 45° |
Valve seat angle (EXHAUST): | 45° |
Valve face angle (INTAKE): | 45° |
Valve face angle (EXHAUST): | 45° |
Valve spring free length (INTAKE): | 31.6 mm (1.244 in) |
Valve spring free length (EXHAUST): | 31.6 mm (1.244 in) |
Rocker arm shaft outer diameter (standard): | 10.473-10.484 mm (0.41232-0.41276 in) |
Rocker arm inner diameter (standard): | 10.500-10.518 mm (0.4134-0.4141 in) |
Tightening torque
Tightening torque specs | |
Cylinder head screws (M8x1.25): | 37.2-42.1 Nm (3.8-4.3 kgf-m, 27.5-31.1 lb-ft) |
Main bearing case screws 1 (M6x1.0): | 12.7-15.7 Nm (1.3-1.6 kgf-m, 9.4-11.6 lb-ft) |
Main bearing case screws 1 (Flywheel side) (M8x1.25): | 23.5-27.4 Nm (2.4-2.8 kgf-m, 17.4-20.3 lb-ft) |
Main bearing case screws 2 (M7x1.0): | 26.5-30.4 Nm (2.7-3.1 kgf-m, 19.5-22.4 lb-ft) |
Connecting rod screws (M7x0.75): | 26.5-30.4 Nm (2.7-3.1 kgf-m, 19.5-22.4 lb-ft) |
Flywheel screws (M10x1.25): | 53.9-58.8 Nm (5.5-6.0 kgf-m, 39.8-43.4 lb-ft) |
Rocker arm bracket nuts (M6x1.0): | 9.8-11.5 Nm (1.0-1.15 kgf-m, 7.2-8.3 lb-ft) |
Bearing case cover screws (M6x1.0): | 9.8-11.5 Nm (1.0-1.15 kgf-m, 7.2-8.3 lb-ft) |
Idle gear shaft screws (M6x1.0): | 9.8-11.5 Nm (1.0-1.15 kgf-m, 7.2-8.3 lb-ft) |
Crankshaft end bolt (M12x1.5): | 117.6-127.4 Nm (12.0-13.0 kgf-m, 86.4-93.6 lb-ft) |
Glow plugs (M8x1.0): | 7.8-14.7 Nm (0.8-1.5 kgf-m, 5.8-10.8 lb-ft) |
Service Data
Valve clearance | |
Intake valve clearance: | 0.145-0.185 mm (0.0057-0.0073 in) |
Exhaust valve clearance: | 0.145-0.185 mm (0.0057-0.0073 in) |
Oil system | |
Lubrication system: | Forced lubrication by pump |
Oil type: | API CD or CE |
Recommended oil: | SAE 30, 10W-30 |
Oil capacity: | 1.9 liters (2.0 US.qts, 1.67 Imp. qts) |
Oil filter type: | Full flow paper filter (cartridge) |
Oil pressure indicating: | Electrical type switch |
Oil pressure: | At Idle speed: 98 kPa (1.O kgf/cm2, 14 psi) At Rated speed: 196.0-441.O kPa (2.0-4.5 kgf/cm2, 28.0-64.0 psi) |
Cooling system | |
Type | Liquid-cooled with pressurized radiator |
Coolant capacity | – |
Thermostat’s valve opening temperature | 69.5-72.5 °C (157.1-162.5 °F) |
Temperature at which thermostat completely opens | 85 °C (185 °F) |
Fuel system | |
Type: | Bosch MD type mini pump |
Injection timing: | 18-20° Before T.D.C. |
Injection nozzle fuel injection pressure: | 13.73-14.71 MPa (140-150 kgf/cm2, 1991-2133 psi) |
Electrical system | |
Battery: | 12V, CCA 600A or equivalent |
Starting motor | Electric starter (12V, 1.2 kW) |
We try to use official documentation and verify the published data, but errors may occur. In addition, specifications of machinery and equipment may vary depending on markets and modifications. We do not recommend the use of this data for spare parts or repairs. Use official service manuals or parts catalogs for your product.
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