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Kubota B21 Backhoe Loader

The Kubota B21 is a four-wheel drive tractor loader backhoe. This model was manufactured between 2001 and 2007. The components of Kubota B21 driveline system: a 61.1 cu.in (1.0 L) Kubota D1005 3-cylinder vertical water-cooled diesel engine, and 3-range hydrostatic transmission with infinite forward and reverse gears.

The engine has a cylinder bore of 2.99" (76 mm), piston stroke of 2.9" (73.6 mm), and rated power of 21 hp (15.7 kW). The max forward speed - 11.1 mph (17.9 km/h), maximum reverse speed - 9.8 mph (15.8 km/h). The open center hydraulic system used a gear pump with fluid flow rate of 7.1 gpm (27 lpm). The hydraulic pressure is 138 bar (2000 psi). The Kubota B21 was equipped with 23x8.50-14 front tires and 12.4x16 rear tires. The wheelbase is 60.4" (1530 mm).

The TL421 loader has a maximum lift height of 88.8" (2250 mm) at pin and bucket dump clearance of 67.2" (1700 mm). The lift capacity is 926 lbs (420 kg) at maximum height (pivot pin), and breakout force is 1543 lbs (699 kg). The estimated cycle times are 3.0 seconds raising to maximum height, and 1.8 seconds maximum bucket dumping. The 54" standard material bucket has a heaped capacity of 8.1 cu.ft (0.23 m3) and weight of 175 lbs (80 kg).

The BT751 backhoe can dig to a max depth of 91" (2335 mm), and 2-ft flat depth of 91.7" (2320 mm). The bucket digging force is 3110 lbs (1410 kg), and dipper stick digging force is 1748 lbs (792 kg). The overall reach from swing pivot at ground level is 121.3" (3080 mm). The backhoe is compatible with 12" (305 mm), 16" (405 mm), 20" (255 mm), and 24" (355 mm) buckets.

Engine Model Kubota D1005
Engine Type Vertical water-cooled 4-cycle diesel
Number of Cylinders 3
Cylinder Bore, in (mm) 2.99 (76.0)
Piston Stroke, in (mm) 2.90 (73.6)
Total Displacement, cm3 (cu.in) 1001 (61.1)
Gross Power, kw (hp) 21.0 (15.7)
Rated Speed, rpm 2600
Maximum Speed, rpm 3800
Low Idle Speed, rpm 900
Combustion Chamber Spherical type (E-TVCS)
Direction of Rotation Counter-clockwise
Compression Ratio 24:1
Firing Order 1-2-3
Fuel System Injection Pump
Injection Pump Type Bosch MD mini
Injection Nozzle Mini nozzle
Governor Type Mechanical
Lubricating System Forced lubrication by trochoid pump
Oil Pressure Indicating Electrical type switch
Oil Filter Type Full flow paper filter (cartridge type)
Valve Clearance (Cold), in (mm) 0.0057-0.0073 (0.15-0.19)
Fuel Tank Capacity, gal (L) 6.3 (24.0)
Oil Capacity, qts (L) 5.1 (5.3)
Coolant Capacity, qts (L) 3.0 (3.1)
Electrical System Rating, Volts 12
Charging Alternator 12V, 150W
Battery Rating 12V, 60 AH

Power Take-Off
PTO Operational Type Live
PTO Horsepower, hp (kW) 13.5 (10.1)
PTO Speed, rpm 540

Transmission Type Hydrostatic
Number of Forward Gears Infinite (3-range)
Number of Reverse Gears Infinite (3-range)
Oil Capacity, qts (L) 29.2 (27.6)
Maximum Forward Speed, mph (kph) 11.1 (17.9)
Maximum Reverse Speed, mph (kph) 9.8 (15.8)

Wheels and Tires
Drive Wheels 4WD 4x4
Steering Configuration Front steer
Steering System Hydrostatic power
Brakes Type Wet disc
Front Tire Size 23x8.50-14
Rear Tire Size 12.4-16
Front Tread, in (mm) 37.8 (960)
Rear Tread, in (mm) 41.3 (1040)

Hydraulic System
Hydraulic System Type Open center
Implement Pump Flow, gpm (Lpm) 7.1 (27.0)
Steering Pump Flow, gpm (Lpm) 1.3 (4.9)
Hydraulic Pressure, Bar (psi) 138 (2000)
Fluid Capacity, gal (L) 7.3 (27.6)
3-Point Hitch Category 1
Draft Sensing or Lift Control Position control
Lift Capacity 24" (610mm) ahead pin, lb (kg) 1017 (460)

Dimensions and Weight
Wheelbase, in (mm) 60.4 (1530)
Height, in (mm) 78 (1980)
Ground Clearance, in (mm) 12 (305)
Turning Radius, in (mm) 114.2 (2900)
Weight, lb (kg) 3990 (1810)

Maximum Lift Height (to pin), in (mm) 88.8 (2250)
Dump Angle, deg 45
Rollback Angle, deg 40
Lift Capacity to Full Height (at Pin), lb (kg) 926 (420)
Breakout Force (at Pin), lb (kg) 1543 (699)
Bucket Width, in (mm) 56 (1420)

Digging Depth, in (mm) 91 (2335)
Digging Depth (2-ft Flat), in (mm) 91.7 (2320)
Reach from Swing Pivot, in (mm) 121.3 (3080)
Swing Arc, deg 180
Bucket Digging Force, lb (kg) 3110 (1410)
Dipperstick Digging Force, lb (kg) 1748 (792)
Bucket Width, in (mm) 16 (405)



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