The Kubota D650-A is a 675 cc (41.2 cu-in) straight-three, water-cooled naturally aspirated diesel engine from Kubota 70 mm series. This engine was used on the Kubota B6100 tractor.
The Kubota D650-A engine has a spherical type сombustion сhamber with glow plug, Bosch K-type mini fuel injection pump, and Bosch throttle type injection nozzle. The compression ratio rating is 22.0. The cylinder bore and the piston stroke are 64.0 mm (2.52 in) and 70.0 mm (2.76 in), respectively.
The D650-A diesel engine produced 14.1 PS (10.4 KW; 14.0 HP) at 2,800 rpm of gross horsepower.
The breakdown of the engine code is as follows:
- D – 3-cylinders
- 65 – Approximate displacement 650 cc
General information
Engine Specifications | |
Engine code | D650-A/D650-AH |
Layout | Straight-3, vertical diesel engine |
Fuel type | Diesel fuel No.2-D |
Production | – |
Displacement | 675 cm3 (41.2 cu in) |
Max. Horsepower (gross) | 14.1 PS (10.4 KW; 14.0 HP) at 2,800 rpm |
Torque output | – |
Injection type | Indirect injection |
Cooling system | Liquid-cooled |
Fuel injection pump | Bosch K-type type mini fuel injection pump |
Fuel nozzle | Bosch throttle type |
Starting system | Electric starting with 12V (0.8 kW) starter |
Starting support device | Glow plug in combustion chamber |
Governor | Centrifugal ball mechanical governor |
Power adder | None |
Firing order | 1-2-3 |
Dimensions (L x W x H): | 471 x 423 x 566 mm (18.5 x 16.7 x 22.3 in) |
Weight | 82.6 kg (182.1 lbs) |
Cylinder block
Cylinder block | ||
Compression ratio: | 22.0:1 | |
Cylinder bore: | 64.0 mm (2.52 in) | |
Piston stroke: | 70.0 mm (2.76 in) | |
Number of piston rings (compression / oil): | 2 / 1 | |
Cylinder inner diameter: | 64.000-64.019 mm (2.5197-2.5204 in) | |
Piston skirt diameter | – | |
Piston ring side clearance: | Second | 0.085-0.112 mm (0.0033-0.0044 in) |
Oil | 0.020-0.055 mm (0.0008-0.0022 in) | |
Piston ring end gap: | Top | 0.250-0.400 mm (0.0098-0.0157 in) |
Second | 0.250-0.400 mm (0.0098-0.0157 in) | |
Oil | 0.200-0.400 mm (0.0079-0.0157 in) | |
Piston pin outer diameter | 20.002-20.011 mm (0.7875-0.7878 in) | |
Crankshaft main journal diameter: | 43.934-43.950 mm (1.7297-1.7303 in) | |
Crankpin diameter: | 36.959-36.975 mm (1.4551-1.4557 in) |
Cylinder head
Cylinder head | ||
Valves: | 6 (2 valves per cylinder) | |
Valve timing: | INTAKE | – |
EXHAUST | – | |
Valve seat width: | INTAKE | 2.120 mm (0.0835 in) |
EXHAUST | 2.120 mm (0.0835 in) | |
Valve stem diameter: | INTAKE | 6.960-6.975 mm (0.274-0.2746 in) |
EXHAUST | 6.960-6.975 mm (0.274-0.2746 in) | |
Valve spring free length: | INTAKE | 35.100-34.800 mm (1.3819-1.3701 in) |
EXHAUST | 35.100-34.800 mm (1.3819-1.3701 in) | |
Camshaft lobe height: | INTAKE | 26.880 mm (1.0583 in) |
EXHAUST | 26.880 mm (1.0583 in) | |
Camshaft journal diameter: | 32.934-32.950 mm (1.2966-1.2972 in) |
Maintenance data
Valve clearance | |
Intake valve | 0.15-0.20 mm (0.006-0.008 in) |
Exhaust valve | 0.15-0.20 mm (0.006-0.008 in) |
Compression pressure | |
Standard | 3.09 MPa, 31.5 kgf/cm2, 448 psi |
Oil system | |
Recommended engine oil | CC or higher |
SAE Viscosity Number | SAE 10W-30, 10W-40 |
Engine oil capacity | 3.9 liters (4.12 US.qts, 3.43 Imp. qts) |
Cooling system | |
Type | Water with pressurized radiator |
Coolant capacity | 4.6 L (4.9 US. qt, 4.0 Imp. qt.) |
We try to use verified sources and official documentation, however, differences between sources or errors in entering information may occur. We do not provide advice on technical issues related to the engines operation or repair. We do not recommend using provided information for engines repairing engines or spare parts ordering, use only official service manuals and spare-parts catalogs.
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