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Kubota D902 Engine

General Technical Data

Kubota D902 Engine Specifications

Engine Model .......... Kubota D902
Engine Type .......... Vertical, water-cooled, 4-stroke diesel
Number of cylinders .......... 3
Bore, mm (in.) .......... 72.0 (2.83)
Stroke, mm (in.) .......... 73.6 (2.90)
Total displacement, cm3 (cu. in.) .......... 898 (54.8)
Gross power, kw (hp) .......... 18.5 (24.8)
Net power, kw (hp) .......... 17.5 (23.5)
Maximum speed, rpm .......... 3800
Idling speed, rpm .......... 900-1000
Combustion Chamber .......... Spherical type (E-TVCS)
Direction of rotation .......... Counter-clockwise
Compression ratio .......... 24:1
Firing order .......... 1-2-3

Fuel System

Fuel injection pump .......... Bosch MD type mini pump
Injection nozzle .......... Bosch "Throttle" type
Injection timing, deg (rad) .......... 20 (0.35) before T.D.C.
Injection pressure, MPa (psi) .......... 13.73 (1991)
Governor .......... All speed mechanical governor

Lubricating System

Lubricating system .......... Forced lubrication by trochoid pump
Oil pressure indicating .......... Electrical type switch
Oil filter .......... Full flow paper filter (cartridge type)

Electrical System

Starting system .......... Electric starting with starter
Starting Motor .......... 12V, 1.2 kW
Starting support device .......... By glow plug in combustion chamber
Battery .......... 12V, 52 AH
Charging Alternator .......... 12V, 480W

Dimensions

Length, mm (in.) .......... 467 (18.4)
Width, mm (in.) .......... 421 (16.6)
Height, mm (in.) .......... 544 (21.4)
Dry weight, kg (lbs.) .......... 72.0 (159)

Kubota D902 Maintenance Data

Fuel type .......... Diesel fuel No. 2-D
Engine oil type .......... SAE 10W-30/15W-40
Engine oil capacity, L (qts) .......... 3.7 (4.0)
Coolant capacity, L (qts) .......... 3.2 (3.4)
Oil filter change interval .......... Every 200 hours
Oil change interval .......... Every 200 hours
Fuel filter change interval .......... Every 400 hours

Kubota D902 Service Specifications

Cylinder Block

Cylinder Liner I.D. .......... 72.000-72.019 mm (2.8347-2.8353 in.)
Cylinder Liner (Oversize 0.25 mm) I.D. .......... 72.250-72.269 mm (2.8445-2.8452 in.)
Camshaft Side Clearance .......... 0.15-0.31 mm 0.0059-0.012 in.)
Camshaft Alignment .......... 0.01 mm (0.0004 in.)
Piston Ring Gap, Top Ring .......... 0.20-0.35 mm (0.0079-0.013 in.)
Piston Ring Gap, Second Ring .......... 0.35-0.50 mm (0.014-0.019 in.)
Piston Ring Gap, Oil Ring .......... 0.20-0.35 mm (0.0079-0.013 in.)
Connecting Rod Alignment .......... 0.05 mm (0.002 in.)
Crankshaft Side Clearance .......... 0.15-0.31 mm (0.0059-0.012 in.)
Crankshaft Alignment .......... 0.02 mm (0.0008 in.)

Timing Gear

Crank Gear to Idle Gear, Backlash .......... 0.0430-0.124 mm (0.00170-0.00488 in.)
Idle Gear to Cam Gear, Backlash .......... 0.0470-0.123 mm (0.00185-0.00484 in.)
Idle Gear to Injection Pump Gear, Backlash .......... 0.0460-0.124 mm (0.00182-0.00488 in.)
Crank Gear to Oil Pump Drive Gear, Backlash .......... 0.0410-0.123 mm (0.00162-0.00484 in.)
Idle Gear Side Clearance .......... 0.20-0.51 mm (0.0079-0.020 in.)

Cylinder Head

Cylinder Head Surface Flatness .......... 0.05 mm (0.0019 in.)
Valve Clearance (Cold) .......... 0.145-0.185 mm (0.00571-0.00728 in.)
Compression Pressure .......... 3.53-4.02 MPa (512-583 psi)
Valve Face (Intake and Exhaust), Angle .......... 0.79 rad (45°)
Valve Seat (Intake and Exhaust), Angle .......... 0.79 rad (45°)
Valve Seat (Intake and Exhaust), Width .......... 2.12 mm (0.0835 in.)
Intake Valve Timing, Open .......... 0.35 rad (20°) before T.D.C
Intake Valve Timing, Close .......... 0.79 rad (45°) after B.D.C
Exhaust Valve Timing, Open .......... 0.87 rad (50°) before B.D.C
Exhaust Valve Timing, Close .......... 0.26 rad (15°) after T.D.C
Tappet to Tappet Guide, Oil Clearance .......... 0.016-0.052 mm (0.00063-0.0020 in.)
Tappet O.D. .......... 17.966-17.984 mm (0.70733-0.70803 in.)
Tappet Guide I.D. .......... 18.000-18.018 mm (0.70867-0.70937 in.)

Fuel System

Injection Pump, Injection Timing (3600 rpm) .......... 0.3317-0.3665 rad (19.00-21.00°) before T.D.C.
Injection Pump, Injection Timing (3600 rpm) .......... 0.3360-0.3621 rad (19.25-20.75°) before T.D.C.
Pump Element Fuel, Tightness .......... 13.73 MPa (1991 psi)
Injection Nozzle, Injection Pressure .......... 13.73-14.70 MPa (1992-2133 psi)
Injection Nozzle Valve Seat (Tightness) .......... If pressure is 12.75 MPa, the valve seat must be fuel tightness

Tightening Torque Specs

Cylinder head cover screw (M6 x 1), Nm (lb.-ft.) .......... 9.81-11.2 (7.24-8.31)
Cylinder head screw (M8 x 1.25), Nm (lb.-ft.) .......... 38-42 (28-31)
Flywheel screw (M10 x 1.25), Nm (lb.-ft.) .......... 54-58 (40-43)
Dynamo’s pulley nut (M10 x 1.25), Nm (lb.-ft.) .......... 40-44 (29-32)
Alternator’s pulley nut, Nm (lb.-ft.) .......... 58.4-78.9 (43.1-58.2)
Drain plug with copper gasket (M12 x 1.25), Nm (lb.-ft.) .......... 33-37 (24-27)
Drain plug with copper gasket (M22 x 1.5), Nm (lb.-ft.) .......... 64-73 (47-54)
Drain plug with rubber coated gasket (M22 x 1.5), Nm (lb.-ft.) .......... 45-53 (33-39)

KUBOTA TRACTORS TROUBLESHOOTING
L235	L2501	L2550	L275	L3110
L3301	L35	L3710	L3901	L4310
L5030	M4700	M5700	M6040	M6800
M8200	M8540	M9000	MX5100	MX5200