________________________________________________________________________________

Kubota D1503 Engine

General Technical Data

Kubota D1503 Engine Specifications

Engine model .......... Kubota D1503
Engine type .......... Vertical, water-cooled, 4-cycle diesel
Number of cylinders .......... 3
Bore and stroke, mm (in.) .......... 83 x 92.4 (3.27 x 3.64)
Total displacement, L (cu.in.) .......... 1.50 (91.4)
Combustion chamber .......... Spherical Type (E-TVCS)
Gross power, kw (hp) .......... 22.8 (30.5)
Net power, kw (hp) .......... 19.8 (26.5)
Maximum speed, rpm .......... 3000
Iidling speed, rpm .......... 750-850
Firing Order .......... 1-2-3
Direction of rotation .......... Counter-clockwise (viewed from flywheel side)
Compression ratio .......... 23.0
Compression Pressure .......... 2.95-3.23 MPa (427-469 psi)

Fuel System

Injection pump .......... Bosch Type mini pump
Injection pressure .......... 13.73 MPa, 1991 psi
Injection timing (Before T.D.C.) .......... 0.314 rad (18 deg)

Electrical System

Starting system .......... Cell starter (with glow plug)
Starting motor .......... 12 V, 1.4 kW
Charging generator .......... 12 V, 480 W
Recommended battery capacity .......... 12 V, 70-80 AH

Dimensions

Length, mm (in.) .......... 572.1 (22.5)
Width, mm (in.) .......... 507.1 (20.1)
Height, mm (in.) .......... 643.3 (25.3)
Dry weight, kg (lbs.) .......... 148 (327)

Kubota D1503 Maintenance Data

Fuel type .......... Diesel Fuel No.2-D
Engine oil type .......... SAE 10W-30
Engine oil capacity .......... 5.6 L (1.48 gals.)
Coolant capacity .......... 5.5 L (1.45 gals.)
Oil filter change interval .......... Every 150 hours
Fuel filter change interval .......... Every 300 hours
Fan belt tension .......... 7-9 mm (0.28-0.35 in.)

Kubota D1503 Service Specifications

Cylinder Block

Cylinder Block Bore, I.D. .......... 40.000-40.025 mm (1.5748-1.5757 in.)
Balancer Shaft Journal 1, O.D. .......... 43.934-43.950 mm (1.7297-1.7303 in.)
Balancer Shaft Bearing 1, I.D. .......... 43.980-44.045 mm (1.7315-1.7340 in.)
Balancer Shaft Journal 2, O.D. .......... 41.934-41.950 mm (1.6510-1.6515 in.)
Balancer Shaft Bearing 2, I.D. .......... 41.980-42.045 mm (1.6528-1.6553 in.)
Balancer Shaft Journal 3, O.D. .......... 21.947-21.960 mm (0.86406-0.86456 in.)
Balancer Shaft Bearing 3, I.D. .......... 21.980-22.041 mm (0.86536-0.86775 in.)
Piston Pin Bore, I.D. .......... 25.000-25.013 mm (0.98426-0.98476 in.)
Top Ring to Ring Groove Clearance .......... 0.050-0.090 mm (0.0020-0.0035 in.)
Top Ring Ring Gap .......... 0.20-0.35 mm (0.0079-0.013 in.)
Piston Pin O.D. .......... 25.004-25.011 mm (0.98441-0.98468 in.)
Small End Bushing, I.D. .......... 25.025-25.040 mm (0.98524-0.98582 in.)
Crankshaft Bend .......... 0.03 mm (0.0001 in.)

Cylinder Head

Valve Clearance (When Cold) .......... 0.18-0.22 mm (0.0071-0.0086 in.)
Top Clearance .......... 0.60-0.70 mm (0.024-0.027 in.)
Cylinder Head Surface Flatness .......... 0.05 mm / 500 mm (0.002 in. / 19.7 in.)
Valve Stem O.D. .......... 7.960-7.975 mm (0.3134-0.3139 in.)
Valve Guide I.D. .......... 8.015-8.030 mm (0.3156-0.3161 in.)
Valve Face Angle (Intake) .......... 0.79 rad (45 deg)
Valve Face Angle (Exhaust) .......... 0.79 rad (45 deg)
Valve Seat Width (Intake) .......... 2.12 mm (0.0835 in.)
Valve Seat Width (Exhaust) .......... 2.12 mm (0.0835 in.)
Valve Seat Angle (Intake) .......... 0.79 rad (45 deg)
Valve Seat Angle (Exhaust) .......... 0.79 rad (45 deg)

Tightening Torque Specs

Cylinder head mounting screw (M11x1.25), Nm (lb-ft) .......... 93.2-98.0 (68.8-72.3)
Oil cooler joint screw (M20x1.5), Nm (lb-ft) .......... 40-44 (29-32)
Fan drive pulley mounting nut (M30x1.5), Nm (lb-ft) .......... 138-156 (102-115)
Camshaft set screw (M8x1.25), Nm (lb-ft) .......... 24-27 (18-20)
Balancer shaft set bolt (M8x1.25), Nm (lb-ft) .......... 24-27 (18-20)
Connecting rod screw (M8x1.25), Nm (lb-ft) .......... 40-45 (30-33)
Flywheel screw (M12x1.25), Nm (lb-ft) .......... 98.1-107 (72.4-79.5)
Screw 1 of main bearing case (M9x1.25), Nm (lb-ft) .......... 46-50 (34-37)
Screw 2 of main bearing case (M10x1.25), Nm (lb-ft) .......... 69-73 (51-54)
B terminal nut of starter (M8x1.25), Nm (lb-ft) .......... 5.9-11 (4.4-8.6)
Pulley nut of alternator, Nm (lb-ft) .......... 58.4-78.9 (43.1-58.2)

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