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Kubota B2150, B9200 - Engine Checking and Service

B2150, B9200 tractors are equipped with a Kubota V1200 4-Cylinder Diesel Engine.

Kubota B2150, B9200 Engine - Cooling System

Fan Belt Tension

Press the fan belt between fan pulley and pulley with your finger at force of 10 kgf (98N, 22 lbs). Check if the fan belt deflection is 7 to 9 mm (0.28 to 0.35 in.). If the deflection is not within the factory specifications, adjust with the tension pulley adjusting nut.

Thermostat's Valve Opening Temperature

Push down the thermostat valve and insert a string between the valve and the valve seat. Place the thermostat and a thermometer in a container with water and gradually heat the water. Hold the string to suspend the thermostat in the water. When the water temperature rises, the thermostat valve will open, allowing it to fall down from the string. Read the temperature at this moment on the thermometer. Continue heating the water and read the temperature when the valve has risen by about 6 mm (0.236 in.). If the measurement is not acceptable, replace the thermostat.

Radiator

Radiator Water Leakage - Pour a specified amount of water into the radiator. Set a radiator tester. Increase water pressure to the specified pressure of 1.4 kgf/cm2 (137 kPa, 20 psi). Check each section for water leakage. When water leakage is excessive, replace the radiator. If water leakage is caused by a small pinhole, correct the radiator with radiator cement. Radiator Cap Air Leakage - Set a radiator tester to the radiator cap. Apply the specified pressure of 0.9 kgf/cm2 (98.1 kPa, 12.8 psi). Check if the pressure drop to less than 0.6 kgf/cm2 (59 kPa, 9 psi) in 10 seconds. If the pressure is less than the factory specification, replace it.

Thermostat and Water Pump

Remove the thermostat cover. Remove the thermostat. Apply a liquid gasket only at the thermostat cover side of the gasket. Remove the fan and fan pulley. Remove the water pump from gear case cover. Remove the water pump flange. Press out the water pump shaft with the impeller on it. Remove the impeller from the water pump shaft. Remove the mechanical seal. Replace the mechanical seal with new one.

Checking and Replenish Cooling Water

Remove the radiator cap and check to see that the cooling water level is just bellow the port. If low, add clean water and antifreeze. Be sure to close the radiator cap securely. If the cap is loose or improperly closed, water may leak out and Kubota V1200 engine could overheat. Do not use an antifreeze and scale inhibitor at the same time.

Checking Fan Belt Tension and Checking Fan Belt Damage

Check the fan belt for damage. Check if the fan belt is worn and sunk in the pulley groove. Replace the fan belt if the belt is damaged or nearly worn out and deeply sunk in the pulley groove. Press the Ian belt between fan pulley and pulley with your finger at force of 98N (10 kgf, 22 Ibs). Check if the fan belt deflection is 7 to 9 mm (0.28 to 0.35 in.). If the deflection is not within the factory specifications, adjust with the tension pulley adjusting bolts.

Kubota B2150, B9200 Engine - Fuel System

Injection Timing

Remove the injection pipes. Set the speed control lever for maximum fuel discharge. Turn the flywheel counterclockwise until fuel flows from the delivery valve holder. Continue to turn the flywheel slowly, and stop it as soon as the fuel level at the tip of the delivery valve holder begins to increase. Check to see if the mark on the flywheel is aligned with the punch mark. If the timing is out of adjustment, readjust the timing with shims.

Fuel Tightness of Pump Element

Remove the injection pipe. Install the injection pump pressure tester to the injection pump. Set the speed control lever to the maximum speed position. Turn the flywheel ten times or more to increase the pressure. If the pressure can not reach the allowable limit, replace the pump element or injection pump assembly.

Fuel Tightness of Delivery Valve

Set a pressure tester to the fuel injection pump. Rotate the flywheel to increase the pressure to 150 kgf/cm (14.7 MPa, 2133 psi). Align the plunger with the bottom dead center. Measure the time needed to decrease the pressure from 150 to 140 kgf/cm2 (14.7 to 13.7 MPa, 2133 to 1990 psi). If the measurement is less than allowable limit, replace the delivery valve.

Nozzle Injection

Nozzle Injection Pressure - Set the injection nozzle to the nozzle tester. Slowly move the tester handle to measure the pressure at which fuel begins jetting out from the nozzle. If the measurement is not within the factory specifications, disassemble the injection nozzle, and change adjusting washer until the proper injection pressure is obtained. Pressure variation with 0.1 mm (0.004 in.) difference of adjusting washer thickness. Approx. 10kgf/cm2 (981 kPa, 142 psi). Nozzle Spraying Condition - Set the injection nozzle to a nozzle tester and check the nozzle spraying condition. If the spraying condition is defective, replace the nozzle piece. Nozzle Holder - Secure the nozzle retaining nut with a vise. Remove the nozzle holder, and take out parts inside. Assemble the nozzle in dean fuel oil. Install the push rod, noting its direction. After assembling the nozzle, be sure to adjust the fuel injection pressure.

Fuel Tightness of Needle Valve Seat

Set the injection nozzle to a nozzle tester. Apply a pressure 130kgf/cm (12.75 MPa, 1849 psi). After keeping the nozzle under this pressure for 10 seconds, check to see if fuel leaks from the nozzle. If fuel should leak, replace the nozzle piece.

Cleaning Air Filter Element and Fuel Filter

Cleaning Air Filter Element - When dry dust adheres. Use dean dry compressed air on the inside of the element. Air pressure at the nozzle must not exceed 690 kPa (7kgf/cm2, 100psi). Maintain reasonable distance between the nozzle and the filter. Cleaning Fuel Filter - Close the fuel filter cock. Unscrew the screw ring and remove the cup, and rinse the inside with kerosene.

Kubota B2150, B9200 Engine - Lubricating System

Engine Oil Pressure and Oil Strainer

Engine Oil Pressure - Remove the oil switch and set a pressure tester. Start the engine. After warming up, measure the oil pressure of both idling and rated speeds. Oil Strainer - Detach the oil pan by lightly tapping the groove of the pan with a wooden hammer. Remove the mounting bolt of oil filter. Detach oil filter, being careful of the O-ring.

Oil Pump

Straighten the claw of the claw washer of the oil pump, and remove the nut. Draw out the oil pump drive gear with gear puller. Remove the four oil pump mounting bolts. Detach the oil pump. Rotor Lobe Clearance - Measure the clearance between lobes of the inner rotor and the outer rotor with a feeler gauge. If the clearance exceeds the allowable limit, replace the oil pump rotor assembly. Clearance between Outer Rotor and Pump Body - Measure the clearance between the outer rotor and the pump body with a feeler gauge. If the clearance exceeds the allowable limit, replace the oil pump rotor assembly. Clearance between Rotor and Cover - Put a strip of press gauge onto the rotor face with grease. Install the cover and tighten the screws. Remove the cover carefully, and measure the width of the press gauge with a sheet of gauge. If the clearance exceeds the allowable limit, replace oil pump rotor assembly.

Checking Engine Oil Level

Level the engine. To check the oil level, draw out the dipstick, wipe it clean, reinsert it, and draw it out again. Check to see that the oil level lies between the two notches. If the level is too low, add new oil to the specified level. When checking the oil level, make sure the tractor is on a flat surface. It is impossible to check accurately if the tractor is not level. Check the oil level before starting or more than 3 minutes after the engine has stopped. At other times, the check will not be accurate as oil stagnates in certain engine parts. When using an oil of different maker or viscosity from the previous one, drain old oil. Never mix two different types of oil.

Changing Engine Oil

After warming up, stop the engine. To change the used oil, remove the drain plug at the bottom of the engine and drain off the oil completely. Reinstall the drain plug. Fill the new oil up to the upper notch on the dipstick. Change the type of engine oil according to the ambient temperature. Above 25C - SAE 30 or 10W-30, 0°C to 25C - SAE 20 or 10W-30, Below 0C - SAE 10 W or 10W-30.

Changing Engine Oil Filter Cartridge

Remove the oil filter cartridge with a filter wrench. Apply engine oil to the rubber gasket on the new cartridge. Screw the new cartridge in by hand. Over-tightening may cause deformation of rubber gasket. After cartridge has been replaced, engine oil normally decreases a little. Check the oil level and add new oil to the specified level.

Kubota B2150, B9200 Engine - Cylinder and Cylinder Head

Cylinder

Cylinder Wear - Measure the I.D. of the cylinder at the six positions with a cylinder gauge to find the maximum and minimum I.D.'s. Get the difference (Maximum wear) between the maximum and the minimum I.D.'s. If the wear exceeds the allowable limit, bore and hone to the oversize dimension. Visually check the cylinder wall for scratches. If deep scratches are found, the cylinder should be bored. Cylinder I.D (V1200-B) - 75.000 to 75.019 mm (2.9528 to 2.9535 in).

Cylinder Head

Cylinder Head Surface Flatness - Thoroughly clean the cylinder head surface. Place a straightedge on the cylinder head's four sides and two diagonal. Measure the clearance with a feeler gauge. If the measurement exceeds the allowable limit, correct it with a surface grinder. Do not place the straight edge on the combustion chamber. Be sure to check the valve recessing after correcting. Cylinder Head Flaw - Prepare an air spray red check. Clean the surface of the cylinder head with detergent. Spray the cylinder head surface with the red permeated liquid. Leave it five to ten minutes after spraying. Wash away the red permeated liquid on the cylinder head surface with the detergent. Spray the cylinder head surface with white developer. If flawed, it can be identified as red marks.

Valve Recessing

Clean the cylinder head surface, valve face and valve seat. Insert the valve into the valve guide. Measure the valve recessing with a depth gauge. If the measurement exceeds the allowable limit, replace the valve. If it still exceeds the allowable limit after replacing the valve, replace the cylinder head. Clearance between Valve Stem and guide - Remove carbon from the valve guide section. Measure the valve stem O.D. with an outside micrometer. Measure the valve guide I.D. of the cylinder head at the most wear part as shown in the figure below with a small hole gauge. And calculate the clearance. If the clearance exceeds the allowable limit, replace the valves. If it still exceeds the allowable limit, replace the valve guide. Push Rod Alignment - Check the both end of the push rod for cracks, damage and unusual wear. Measure the bending of the push rod with a dial indicator. If the measurement exceeds the allowable limit, replace the push rod.

Correcting Valve

Correcting Valve Seat - Slightly correct the seat surface with a 45 or 30 degrees valve seat cutter. Fitting the valve, check the contact position of the valve face and seat surface with prussian blue. Visual check - If the valve has been used for a long period, the seat tends to come in contact with the upper side of the valve face. Grind the upper surface of the seat with a 0.262 rad (15 degrees) valve seat cutter until the valve seat touches to the center of the valve face. Grind the seat with 45/30 degrees valve seat cutter again, and visually recheck the contact between the valve and seat. Valve Spring Setting Load - Place the valve spring on a tester and compress it to the same length it is actually compressed the engine. Read the compression load on the gauge. If the measurement is less than the allowable limit, replace it.

Replacing Valve

Replacing Valve Guide - Press the used value guide out from the cylinder head's lower side using a valve guide replacing tool. Apply engine oil to the outer surface of the new valve guide, and press fit the valve guide from the cylinder head's upper side until the flange part of the valve guide contacts the cylinder head. Be careful not to strike valve guide with a hammer, etc. during replacement. Free Length and Tilt of Valve Spring - Measure the length A with vernier calipers. If the measurement is less than the allowable limit, replace. Put the spring on a surface plate, place a square on the side of the spring, and check to see if the entire side is in contact with the square. Rotate the spring and measure the maximum. If the measurement exceeds the allowable limit, replace. Check the entire surface of the spring for scratches. Replace it, if any.

Kubota B2150, B9200 - Timing Gear and Camshaft

Timing Gear

Timing Gear Backlash - Set a dial indicator (lever type) with its tip on the gear tooth. Move the gear to measure the backlash, holding its mating gear. If the backlash exceeds the allowable limit, check the oil clearance of the shafts and gear. If the oil clearance is proper, replace the gear. Clearance between Idle Gear Shaft and Idle Gear Bushings - Measure the idle gear shaft O.D. with an outside micrometer. Measure the idle gear bushings I.D. with an inside micrometer, and calculate the clearance. If the clearance exceeds the allowable limit, replace the bushing. Replacing Idle Gear Bushings - Press the used bushings out using a idle gear bushing replacing tool. Press fit new bushings.

Camshaft

End Play of Camshaft - Pull the cam gear with the camshaft to its end. Measure the clearance between the cam gear and camshaft stopper. If the clearance exceeds the allowable limit, replace the camshaft stopper. Camshaft Alignment - Support the camshaft with V blocks on the surface plate at both end journals. Set a dial indicator with its tip on the intermediate journal. Measure the camshaft alignment. If the measurement exceeds the allowable limit, replace the camshaft. Intake and Exhaust Cam Height - Measure the height of the cam at its highest point with an outside micrometer. If the measurement is less than the allowable limit, replace it. Oil Clearance of Camshaft Journal - Measure the camshaft journal O.D. with an outside micrometer. Measure the cylinder block bore I.D. for camshaft with an inside micrometer. Calculate the oil clearance. If the clearance exceeds the allowable limit, replace the camshaft.

Kubota B2150, B9200 - Piston and Connecting Rod

Piston

Piston Pin-Bore I.D. - Measure the LD. of the piston pin-bore in both the horizontal and vertical directions with a cylinder gauge. If the measurement exceeds the allowable limit, replace the piston. Oil Clearance between Piston Pin and Small End Bushing - Measure the O.D. of the piston pin where it contacts the bushing with an outside micrometer. Measure the I.D. of the piston pin bushing at the connecting rod small end with a cylinder gauge. Calculate the oil clearance. If the clearance exceeds the allowable limit, replace the bushing. If it still exceeds the allowable limit, replace the piston pin.

Piston Ring

Clearance between Piston Ring and Groove - Remove carbon from the ring grooves. Measure the clearance between the ring and the groove with a Feeler gauge or depth gauge. If the clearance exceeds allowable limit, replace the ring since compression leak and oil shortage result. If the clearance still exceeds the allowable limit after replacing the ring, replace the piston. Piston Ring Gap - Insert the piston ring into the lower part of the liner (the least worn out part) with the piston. Measure the ring gap with a feeler gauge. If the gap exceeds the allowable limit, replace the ring.

Connecting Rod

Replacing Connecting Rod Small End Bushing - Press out the small end bushing with a connecting rod small end bushing replacing tool. Clean a new small end bushing and bore, and apply engine oil to them. Insert a new bushing onto the tool and press-fit it. with a press so that the seam of bushing positions as shown in the figure, until it is flash with the connecting rod. Drill a hole to the bushing with aligning the oil hole of connecting rod using 4.0 mm dia. (0.157 in. dia.) drill. Oil clearance between piston pin and small end bushing - 0.015 to 0.075 mm. Connecting Rod Alignment - Since the I.D. of the connecting rod small end bushing is the basis of this check, check the bushing for wear beforehand. Install the piston pin into the connecting rod. Install the connecting rod on the connecting rod alignment tool. Put a gauge over the piston pin and move it against the face plate. If the gauge does not fit squarely against the face plate, measure the space between the pin of the gauge and the face plate. If the measurement exceeds the allowable limit, replace the connecting rod.

Kubota B2150, B9200 - Crankshaft

End Play of Crankshaft

Move the crankshaft to the flywheel side. Set a dial indicator to the crankshaft. Measure the end play by pulling the crankshaft toward the crank gear. If the measurement exceeds the allowable limit, replace the thrust bearings. Crankshaft Alignment - Support the crankshaft with V-blocks on the surface plate and seta dial indicator with ttstip on the intermediate journal at right angle. Rotate the crankshaft on the V-blocks and get the misalignment (half of the measurement). If the misalignment exceeds the allowable limit, replace the crankshaft.

Oil Clearance between Crank Pin and Crank Pin Bearing

Clean the crank pin and crank pin bearing. Put a strip of press gauge on the center of the crank pin in each direction as shown in the figure. Never insert the press gauge into the crank pin oil hole. Install the connecting rod cap and tighten the screws to the specified torque, and remove the cap again. Fasten the crankshaft so that it does not turn. Measure the amount of the flattening with the scale and get the oil clearance. If the clearance exceeds the allowable limit, replace the bearing. When the oil clearance is to be measured by removing the crankshaft, tighten the connecting rod cap with the specified torque, then measure the crank pin bearing I.D. with a cylinder gauge or an inside micrometer. And measure the crank pin O.D. with an outside micrometer. Calculate the oil clearance.

Crankshaft Sleeve Wear and Replacing Crankshaft Sleeve

Measure the wear of the crankshaft sleeve using a . surface roughness tester. If the measurement exceeds the allowable limit, replace the crankshaft sleeve. Remove the used crankshaft sleeve using a special-use puller set. Set the sleeve guide C to the crankshaft. Set the stopper C to the crankshaft. Heat a new sleeve to a temperature between 150 and 200C, and fix the sleeve to the crankshaft. Press fit the sleeve using the auxiliary socket for pushing.

Crankshaft Bearing

Oil Clearance between Crankshaft Journal and Crankshaft Bearing 1 - Measure the O.D. of the crankshaft journal with an outside micrometer, Measure the I.D. of the crankshaft bearing 1 with an inside micrometer. Calculate the oil clearance. If the clearance exceeds the allowable limit, replace the crankshaft bearing 1. Replacing Crankshaft Bearing 1 - Press out the bearing 1 with crankshaft bearing 1 replacing tool. Clean a new bearing 1 and bore, and apply engine oil to them. Press fit a new bearing 1 using a inserting tool, taking due care to see that the seam of bearing 1 faces the exhaust manifold side. Oil Clearance between Crankshaft Journal and Crankshaft Bearing 2 - Clean the crankshaft journal and crankshaft bearing. Put a strip of press gauge on the center of the journal. Never insert the press gauge into the oil hole of the journal. Install the main bearing case and tighten the screws to the specified torque, and remove the cases again. Measure the amount of the flattening with the scale and get the oil clearance. If the clearance exceeds the allowable limit, replace the crankshaft bearing.