Hand-held tractors are light and flexible. They are used by many machines and are a good helper for agricultural production. In order to increase production efficiency and extend the service life of tractors, besides insisting on using the correct methods of operation, faults must be discovered and faults must be corrected. Now let's learn a little, common fault diagnosis, and simple maintenance knowledge. Experts introduced the walking tractor from the engine, transmission system, braking system, walking system, electrical equipment, work devices and other components. We can simply be divided into two parts: engine and chassis. Do not look at its parts, faults can be found by listening, seeing, sniffing, and touching. First, the engine starts difficult to see how the common fault of the engine is excluded. Walking tractors generally start to feel difficult to start until they cannot start. The reasons for the start-up difficulties are: low ambient temperature, problems with diesel fuel, impaired oil passage, improper engine adjustment, and low cylinder pressure. Ambient temperature is too low When the ambient temperature is below -15 degrees, the tractor is parked for too long, and when the engine is completely cooled, the engine is not easy to start. In this case, there are several ways to solve it. First, warm up the engine oil. Put oil from the sump. heating. Then raise. Second, inject 90 to 95 degrees of hot water into the tank. After filling, open the drain switch on the cylinder to make it flow. After the temperature of the water to be discharged reaches 30 to 40 degrees, close the drain switch. Diesel problem When the diesel label is not proper, the viscosity is too large and it is not easy to flow, which makes the oil pump unable to suck into the oil, causing difficulty in starting. The applicable season of several common light diesel oils is: No. 0: from April to September in the whole country, south of the Yangtze River in winter. No. 10: In the winter south of the Great Wall, it is harsh in the south of the Yangtze River. No. 20: In the north of the Great Wall and in the northwest during the winter, the south of the Great Wall and the north of the Yellow River are severe winters. No. 35: Winter in the northeast and northwest. No. 50: northeast, north and northwest regions. When the tractor is always in good condition, it is difficult to start the engine after using the newly refueled diesel, indicating that the injected diesel has poor quality, impurities, or moisture. Therefore, when refueling outdoor diesel, it is advisable to let it stand for 48 hours in order to fully precipitate water and impurities before use. The bottom of the fuel tank is best used for other purposes. Inadequate diesel oil intake into the cylinder, the engine will certainly start difficult. The reason is that the oil route is not accessible. The oil circuit is blocked. Check whether the fuel tank switch is open. Then remove the dirt from the fuel tank cap and keep the vent or vent tube open. Loosen the bleeder screw on the fuel injection pump. If air bubbles are trapped in the oil flow, it means that the air enters the air path, forming a gas resistance, which reduces or stops the fuel entering the cylinder, causing difficulty in starting. Exclude the air in the oil circuit. Tighten each hose connector. Check the seal at the diesel filter cover. When loosening the fuel pump bleeder screw and shaking the crankshaft pump oil, the sensor has a large resistance, and the bleeder screw has a small amount of oil and is blocked by the diesel filter. Diesel filter should be cleaned. Improper Engine Adjustment After the engine has been used for a period of time, vibration and wear make the fuel pump's technical parameters change. These changes often cause start-up difficulties. At this point, you need to readjust these parameters. When adjusting the fuel supply advance angle of the fuel injection pump, remove the high-pressure pipe nut at the end of the injection nozzle, and loosen the high-pressure fuel pipe nut at the other end so that the fuel pipe is placed horizontally with the pipe nozzle facing upward. Put the hand throttle on the fuel supply position. Turn the flywheel. Fill the high pressure fuel line with diesel. Slowly turn the flywheel again. When the oil level at the nozzle begins to rise, observe the supply line on the flywheel and align it with the reticle on the tank. The fuel supply advance angle should be 16 to 20 degrees. If the reticle advances or lags, adjust it. Adjustments generally use increasing or decreasing shims. Add gaskets, delay oil supply, reduce gaskets, and provide oil in advance. Adjust until the reticle alignment. Pay special attention when installing the fuel injection pump. The plug adjustment arm should be embedded in the speed control lever groove. this point is very important. The inspection method is to pull out the oil dipstick and touch the adjusting arm with your finger. When adjusting the throttle, the adjusting arm should swing with the throttle, otherwise it must be reinstalled. When the cylinder pressure is low, the decompression mechanism is not opened, and the crankshaft of the diesel engine can be shaken relatively easily, and when there is a pronounced “surge, breathe†sound in the intake and exhaust pipes, it indicates that the valve is leaking. At this time, the valve clearance needs to be adjusted. When adjusting, turn the flywheel so that the top dead center line on the flywheel aligns with the reticle on the tank. Use a wrench and a screwdriver to loosen the lock nut and adjustment screw on the rocker arm and insert the gauge between the valve and the rocker arm. Turn the adjusting screw to adjust the intake valve clearance to 0.35 mm and the exhaust valve to 0.45 mm. Finally tighten the lock nut. Another reason for valve leakage is that the valve is not closed tightly. This kind of failure requires repair stations, grinding valves and valve seats. Another reason for the low cylinder pressure is the severe wear of the cylinder. The inspection method is to add a little lubricating oil to the vent pipe. Then cradles start. If you feel the pressure increases, it means that the piston ring or liner wears badly, and the cylinder compression is bad. In the event of such failure, it is also necessary to go to the pits and replace the piston rings or cylinder liners. Second, the abnormal engine exhaust smoke black smoke engine when the mixture can not be completely burned, it will smoke black. At this time, first reduce the load on the tractor. If the smoke becomes lighter, it means that the reason for the black smoke is that the load is too heavy and the load can be reduced. If you continue to black smoke after reducing the load, you need to remove dust from the air cleaner and remove carbon deposits and oil from the exhaust pipe. If the air cleaner and exhaust pipe are cleaned, the engine still emits black smoke. You need to check if the fuel supply timing is too late. If it is too late, adjust fuel injection timing. After adjusting the fuel supply timing, black smoke cannot be excluded and the injector should be cleaned. When cleaning the injector, remove the injector and clean the oil and coke around the nozzle. Rotate the high pressure hose to one side and install the injector. Shake the crankshaft and observe the fuel injection. If drip, partial or non-atomizing, the injection pressure should be adjusted. When adjusting, remove the injector cap and use a screwdriver to rotate the regulator screw. Until the injection is in a normal mist, all of the above methods can not be used to eliminate black smoke. This is because the cylinder wears seriously and the cylinder pressure is insufficient. In this case, the piston ring or cylinder liner should be replaced at the service station. The engine emits blue smoke. When the engine oil enters the combustion chamber, it will emit blue smoke. First check the amount of oil in the oil pan. If more than the upper limit is exceeded, excess oil should be released. Check the oil in the air filter oil pan. The amount of oil should not exceed the oil surface ring groove. If too much, release the oil in the oil pan. After the amount of oil in the sump and the oil pan is normal, the blue smoke still cannot be excluded. The engine wear is serious and the engine should be repaired. White Smoke from the Engine When the fuel contains water or burns badly, it will emit white smoke. First release all the diesel fuel in the tank. Check the tank, if the cooling water is not reduced at the same time, there may be a cylinder damage leak. In this case, go to the repair station for further inspection. If no significant lack of cooling water, add new diesel. Start the engine, no-load low-speed warm car. After the temperature of the engine has risen, the load will be increased and the white smoke will be eliminated by itself. We can also diagnose this. If the white smoke emitted by the exhaust pipe is not continuous, it is a unitary one, indicating that the injector is drip and the atomization is bad. You should clean the injector. If the white smoke discharged from the exhaust pipe is continuous in a large amount, and the power of the engine is significantly reduced, the temperature of the exhaust gas and the temperature of the cooling water are reduced. The injection pressure is insufficient and the needle valve is dead. The injection pressure should be adjusted. Third, the engine overheating The engine overheated performance is that the cooling water in the tank quickly boils. The engine is overheated and can be diagnosed and excluded from the following aspects. Check the water tank for lack of water. When the cooling water is insufficient, turn the tractor to a place where there is water, run it at idle speed until the water temperature drops, and then add cooling water. Cooling water should be added until the buoy reaches its highest position. Note that when the engine overheats, you can't rush into cold water to prevent the fuselage from breaking. If the engine temperature is too high, the engine cannot be turned off immediately to prevent the piston from being killed in the cylinder. The water tank is not short of water, but when the engine temperature is too high, the debris in the water tank, inside the tank, and water jacket should be removed. When cleaning the exterior of the tank, wet the surface of the tank with water and then flush it forward from the back of the tank. For clinging to solid debris, use a brush to clean it. Do not use tools such as blades to avoid damaging the tank. When cleaning the inside of the water tank and the water jacket, first discharge the old cooling water, fill the water tank with tap water, start the engine to run for 5 minutes and release it. The debris will be removed with the water. When there is excessive deposition of scale in the water jacket, remove the water tank. Slowly pour the hydrochloric acid into water, mix well, and prepare a 25% hydrochloric acid solution. The hydrochloric acid solution was injected into the interior of the water jacket and left for 10 minutes to dissolve and release the scale. Release hydrochloric acid solution and rinse with water. If scale is excessive, wash it several times. The fuel supply is too late and the coke deposit in the combustion chamber plus the cooling water and the cleaning water tank can not eliminate the problem of engine overheating. The oil supply advance angle should be checked and adjusted as described above. If there is no fault in the advance angle of the oil supply, it is necessary to go to the service station to remove the carbon from the combustion chamber. IV. Insufficient oil pressure When the diesel engine is working normally, the red mark of the indicator valve should rise. If the rise is not high or does not rise, the oil pressure is insufficient. The diagnosis can be excluded from the following aspects. Pull out the oil dipstick with too little oil and check the amount of oil. The oil level should be between the two reticle lines. If less than the lower limit, you should make up for the oil. The oil pressure is normal at the beginning of engine start-up. However, after a while, the oil pressure drops rapidly. Pull out the oil dipstick and the oil is normal. With your fingers, the viscosity decreases. Observe carefully that the engine oil is black, there are small drops of water, or diesel smell can be heard. At this time, the oil must be replaced. At the time of replacement, the old engine oil is released hot and the same type of engine oil is selected. Plugging of the oil filter If there is no problem with the oil, check that the filter on the front of the oil pump is blocked. When checking, remove the rear end cap of the engine. Check the filter for clogging. Clean the filter with clean diesel or kerosene. When cleaning, remove the coil from the filter cover, remove the filter, and clean the inside and outside of the filter. Install the oil filter in reverse order. Above we introduced the diagnosis and elimination of common engine failures. Next, we will introduce some of the chassis common fault diagnosis and troubleshooting. V. Difficult to engage the gear to pull the clutch brake handle to the disengaged position. When the shift lever is pulled, it feels hard to assemble, or there is a gear collision sound when the gear is engaged, or it cannot be stopped at all. The reasons and exclusion methods are as follows. The clutch is not clear. When excluding, first adjust the clutch clearance. Put the clutch brake handle back into the engaged position. Insert the gauge into the separation between the lever head and the release bearing. The gap should be 0.4 to 0.7 mm. The three gaps should be basically the same. If the gap does not meet the requirements, or there is a large gap between the three gaps, it should be readjusted. The clutch clearance meets the requirements and the free travel of the clutch brake handle is checked. The free stroke of the clutch brake handle should be 25-30 mm. When there is discrepancy in the itinerary and requirements, adjust it. Check if the shift lever fastening screws are loose. Tighten the nut on the shift lever connector and the shifter pin. Check if the shift lever is deformed. If there is any deformation, it should be corrected and repaired. Clutch bearings lack of oil When the clutch brake handle is pulled up, the disengagement bearing emits a "sand, sand" sound, which is generally a lack of bearing oil. When refueling the disengaging bearing, wipe the oil sludge outside the bearing first to make the bearing rotate flexibly. Then use an oil can to add lubricant to the bearing. If the release bearing does not rotate, metal friction sounds when contacted with the release lever and the sound disappears when the clutch brake handle is released. This is usually a bearing ablation damage. Another cause of abnormal clutch sound is loose clutch bolts or internal clutch damage. In this case, you should go to the service station for replacement. 6. The use of misaligned tires has not been used for a long time, but the wear has been severe. Should check the tire pressure, too high and too low will accelerate tire wear. The standard value should be two kilograms per square centimeter. Inflate or deflate the tire to a standard value. When the left and right tires wear unevenly, they can be used interchangeably. When the tire needs to be replaced, the left and right tires must be replaced at the same time to ensure that the tires on both sides have the same adhesion. But you must pay attention to the direction of the tread pattern. Look from the front of the tractor, the pattern should be "eight", or "person", can not be installed against. Frequent adhesion of diesel oil, engine oil, or other chemical solvents to the tire will increase tire damage and should always keep the tread clean. When the steering rod is too long or too short, pull the steering handle and the tractor cannot steer or turn hard because the steering rod is too long or too short. The length of the steering rod should be checked and adjusted. The standard for the length of the steering rod is: gripping the steering handle. When there is a distance of 2 to 4 cm between the steering handle and the plastic handle, the steering operation should be performed accurately. If the distance is too large, the steering rod should be adjusted. If the distance is too small, the steering rod should be shortened. Check for excessive wear on the steering arm hinges. Excessive wear should be replaced. Check for serious wear on the steering fork journal and the inside of the steering cover bore. If it is seriously worn, it must be replaced. 7. When the brake is in misaligned driving, if the joystick has not been pulled out of the disengagement position, it will act as a brake, indicating that the brake is premature. If the joystick is pulled back from the disengaged position and it does not act as a brake, the brake is too late. When checking, pull the operating handle from the engaged position to the disengaged position. Hold up the tractor and turn the tires so that the tires can rotate freely. Pull the operating handle from the disengaged position to the braking position. When you turn the tire firmly, the tire should not turn and it should be firmly braked. If you do not meet the above requirements, loosen the lock nut. Turn the fork on the lever. Then tighten the lock nut. Above, we have learned about the diagnosis and elimination of common faults of walking tractors. I believe that through your efforts and practice, we will quickly use the tractor with correct, low-cost and safe use, so that the tractor will play a more active role in production.
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