In detail: do-it-yourself hopper walk-behind tractor repair from a real master for the site my.housecope.com.
If you actively use small-sized agricultural machinery, like walk-behind tractors, you probably encountered some problems in their operation. One of the most common questions among owners of this type of equipment is "why does the walk-behind tractor stall?"
In the overwhelming majority of cases, this is due to engine malfunctions, which can be eliminated independently without contacting specialized workshops.
With a compact size, the walk-behind tractor is a rather complex mechanism, for diagnosing the malfunctions of which you should first understand what the function of its main components is.
A classic walk-behind tractor consists of the following systems and elements:
fuel system, which includes a carburetor, a fuel tank complete with a crane, a supply hose and an air filter;starter manual or electric (in professional models), designed to spin the main shaft (this function is performed by the starter cord);cooling system, driven by the rotation of the crankshaft and providing the injection of air flow by the impeller of the flywheel;ignition system responsible for the formation of a spark;gas distribution system supplying a fuel mixture to the engine cylinders and allowing the release of gaseous waste.Since the engine is the main element in the design of the walk-behind tractor, the largest number of faults are associated with it. The first signs of engine malfunction are reduced performance indicators.
If the engine runs poorly, we recommend checking:
Video (click to play).
is it warmed up enough, especially in the cold season;
air filter contamination level;
the quality of the fuel used;
the correctness of the ignition system;
the presence of blockages from combustion products in the muffler;
the level of contamination of the carburetor;
the integrity of the piston mechanisms.
If the engine does not start at all, check:
the position of the motor - when tilted about the center axis, it must be put back in place to avoid more serious malfunctions;
the availability of a sufficient amount of fuel;
the level of contamination of the tank lid;
fuel supply system to the carburetor;
the level of contamination of the spark plugs and the fuel tank valve.
The most affordable and popular models preferred by summer residents and farmers are: walk-behind tractor MB, MB 1, Agro, Mole, Zirka and Zubr. Repair of the Zubr walk-behind tractor, like all the other listed models, can be easily done with your own hands by replacing certain structural elements by purchasing them (including the old model) at specialized disassembly.
However, we will look at the most common technologies for self-diagnosis and troubleshooting of key elements in their design.
Restoring the function of the carburetor is easy with the help of its competent cleaning from blockages. To eliminate contamination, the unit is disassembled, cleaned in accordance with the manufacturer's recommendations and re-adjusted. The algorithm of actions is in the instruction manual for walk-behind tractors.
You can adjust the carburetor by adjusting the operating parameters of the float, which is located in a partially closed chamber.
All manipulations are reduced to restoring the uniformity of its immersion by eliminating the deformation of the bracket with which it is attached to the piston system.
Adjustment can be made with the needle valve closed or open. In both cases, the elimination of deformation of the bracket is carried out manually or using a screwdriver, all actions must be precisely directed.
Along with the repair or diagnostics of the state of the carburetor, it is also recommended to adjust the valves on the walk-behind tractor. The procedure involves checking the tightness of each valve to restore optimum valve clearance. Adjusting the valves of the walk-behind tractor allows you to restore its functions, the exceptions are serious breakdowns in the carburetor or other systems of the unit.
VIDEO to the menu ↑
The high-pressure fuel pump, or the high-pressure fuel pump, performs one of the key functions in the operation of the walk-behind tractor - at a certain point in the cycle, it supplies metered fuel to the engine cylinders.
Symptoms of a pump malfunction are:
violations in the supply of fuel to the engine injectors;
fuel leaks as a result of mechanical wear;
atypical noises and sounds during work;
failure of basic settings.
A properly adjusted fuel pump ensures the correct operation of the engine and other systems of the walk-behind tractor. The design of this element is rather complicated, therefore we do not recommend repairing it yourself.
As you know, mechanisms based on a crankshaft are driven by a transmission, which can be provided by a serviceable belt on a walk-behind tractor. As practice shows, this is one of the most vulnerable and subject to mechanical wear of elements in the design of the walk-behind tractor.
timely transfer of torque from the engine crankshaft to the gear shaft;
adjusting the engine load during gear shifting;
the ability of equipment to move from a place and stop without necessarily stopping the motor.
If you notice atypical behavior of the walk-behind tractor in one of the cases listed above, we recommend that you carefully inspect the condition of the belt and check the level of its tension. As practice shows, it is quite simple to repair the tensioner for a walk-behind tractor with your own hands by welding a part of the same size and configuration from a metal corner.
Another indicator of problems with the transmission is a violation of the parameters for reducing the speed to the operating indicator, the adjustment of which is provided by a creeper, or gearbox. It is very difficult to make this element for a motor-cultivator on your own, since from the point of view of design it is similar to a gearbox. You can buy it inexpensively in almost any city, and some models, for example, the gearbox of the MB walk-behind tractor, can be used for repairing other models of motor cultivators.
In this material, we will consider typical malfunctions of a walk-behind tractor engine and how to fix them.
Typically, there are two types of engine faults:
1. The engine will not start.
2. The engine does not work satisfactorily (it does not gain power, it runs intermittently, the engine stops).
If the engine does not start, then in search of malfunctions and their further elimination, you should perform the following steps to identify the causes.
- Checking the presence of fuel in the tank (checking the fuel system)
- Checking the carburetor air damper (when starting a cold engine, the damper must be closed)
- Checking the flow of fuel to the carburetor.
- If there is no fuel entering the cylinder, a dry plug is indicated. Check the presence of fuel in the fuel tank, fuel flow to the carburetor by removing the fuel hose from the inlet fitting. For the K45 carburetor, press the sinker until the fuel leaks through the drain hole.
- If fuel does not flow to the carburetor, unscrew the fuel cock, disassemble it and clean the filter from dirt.
- When fuel enters the carburetor, but there is no fuel supply to the cylinder, check the operation of the fuel valve and the cleanliness of the jets.
- To check the KMB-5 carburetor, remove it from the engine, drain the gasoline from the float chamber, then supply air through the fuel inlet in the operating position of the carburetor. The air should be easily blown through.
- Repeat the purge with the carburetor turned 180 degrees, in this position the air supply should stop. If the result is the same as described, the fuel valve is working properly.
- The fuel level in the float chamber is regulated by the float tongue, the normal fuel level should be 30-35mm.
- After all actions with the carburetor and installing it back, the carburetor should be adjusted.
- It so happens that the engine does not start from excess fuel, this is evidenced by a wet plug. Dry the cylinder and “bleed” the engine with the plug turned out, before that, turn off the fuel supply.
- If the plug is dirty with deposits, clean it and check the gap between the electrodes, usually the correct gap is 0.8mm. Next, you should check for the presence of a spark, if there is no spark, then there may be a malfunction in the electrical circuit or a large gap between the ignition coil and the magnetic circuit.
If the engine starts, but does not develop the required power, runs intermittently, stalls, etc., the reasons for this may be the following malfunctions:
- The air filter is dirty, as a result of which the air in the carburetor is insufficiently supplied.
- Defective ignition system. You should check it, as well as check the candle, the gaps between the electrodes, etc.
- Clogged muffler with combustion products. The muffler should be disassembled for cleaning.
- Dirty carburetor and incorrect setting.
- Low power may be due to wear of the cylinder-piston group. The compression should be 8 atm. Compression can be checked by attaching a compression gauge to the spark plug hole, turning the engine shaft with a starter.
Read also, information on how to make a trailer for a walk-behind tractor with your own hands.
If the engine of the walk-behind tractor does not turn off, first of all it is necessary to pay attention to the operation of the shutdown button. It is necessary to disassemble, check and, if necessary, replace or clean the contacts.
VIDEO
The material presented in this article is especially in demand for people who repair their equipment on their own. Further, the main "subtleties" regarding the repair of the motoblock gearbox will be touched upon. To go directly to the topic of repair, you need to understand the gearbox design. Looking ahead, it is necessary to say: the structure of the gearboxes of modern walk-behind tractors is similar to each other, there are only minor differences in one or another model.
So that the question "How to disassemble the gearbox of a walk-behind tractor?" Does not arise, you need to be familiar with all the details. We list the main parts and components of any modern walk-behind tractor: covers and pulley; bushings with bearings; lever, axle and shift fork; input shaft block with gear; input and output shaft of the motoblock gearbox. Components: washers and seals; right and left semiaxis; clutch and clutch fork; bracket and spring.
In most cases, problems in the gearbox of the walk-behind tractor arise due to overloads. Such breakdowns include the bursting of the bushings on the metal chain, which leads to the so-called "slip". Also, owners of walk-behind tractors very often find broken gearshift bushings. In order to avoid such troubles, experienced owners advise to switch gears only during a complete stop of the equipment, in no case on the move. In addition, star breakage is considered to be a common phenomenon. That is, factory welding is not enough for the star to withstand the overload.
It is very easy to "get out" of this annoying situation, you just need to return the star to its original position and grab it by welding with much better quality. Lateral loads lead to wear of the support washer, after which the bushings come off the chain. In addition to the above, it is necessary to periodically check the oil level in the gearbox and replace it.
Monitor the amount of oil constantly. Otherwise, neglect of technology will lead to fatal consequences. Fresh oil is poured every 50 hours. Along with this, excessive loads should be avoided, which ultimately lead to the rapid development of mechanisms and components. Let's go directly to changing the oil:
We install the equipment on a flat area. We find a probe, 70 cm long.
The dipstick is bent and pushed into the hole for filling the oil until it stops, after which we take out the rod.
We observe the oil level, which should be at least 25 cm. 2 liters of oil, at least 1.5 liters, are added to the dry gearbox.
The filling oils must be GOST. It makes no sense to use cheap oil, because sooner or later, it will cause breakdowns inside the gearbox of the walk-behind tractor.
VIDEO
Like any technique, a walk-behind tractor requires timely maintenance and repair. And it is advisable to entrust their implementation to specialists who have the necessary tools and equipment and know their job well. However, if you are also familiar with the device of internal combustion engines and understand the topic of mechanical engineering, then you can do a lot of what may be required to restore the machine's performance on your own.
Diesel and gasoline engines have different motor resources. For the former, the normal figure is 4000 m3 / h, but the latter are capable of providing only 1500 m3 / h. Despite this, diesel models of walk-behind tractors are not in high demand. After all, both when buying and during operation, they are much more expensive. Therefore, most likely you are working with a walk-behind tractor equipped with a gasoline (carburetor) engine.
All breakdowns that may arise during the operation of agricultural mini-equipment can be conditionally divided into two categories:
Engine malfunctions: startup problems;
malfunctions.
Malfunctions of other units and mechanisms: improper clutch operation;
breakdowns in the gearbox;
problems with the chassis;
malfunctions of control and automation;
malfunctions of walk-behind tractor systems (cooling, lubrication, etc.).
In many ways, the success of repairing a suddenly out of order machine depends on the correctness of the diagnostics. With regard to maintenance, it is carried out precisely in order to identify small malfunctions, which subsequently lead to serious ones.
If you do not have the necessary knowledge, premises, tools and materials necessary for servicing and repairing the motor, entrust the work to a specialist!
If attempts to start the walk-behind tractor were unsuccessful, this means that there are malfunctions in the engine or starting system. In order to determine the source of the breakdown, you first need to check the spark plugs.
If the spark plugs are dry, this means that the fuel mixture is not entering the engine cylinders. There may be several reasons for this:
there is no fuel in the tank;
the fuel supply valve is closed;
the hole in the gas tank plug is clogged;
foreign objects have entered the fuel supply system.
To fix problems with the fuel supply, you must:
Fill the tank of the walk-behind tractor.
Open the fuel cock.
Clean the drain hole located in the fuel filler cap.
Remove the fuel cock, drain the fuel tank and rinse it with clean gasoline. After that, remove the connecting hose on the side of the carburetor and blow it out together with the carburetor nozzles without disassembling the latter using the fuel pump.
If fuel enters the carburetor but does not reach the cylinder, the problem is with the carburetor itself. To eliminate it, this unit must be removed, disassembled and cleaned. Well, after that - assemble and install in place. Therefore, before performing all the necessary manipulations, it does not hurt at all to refresh the memory of the device and the principle of operation of the carburetor.
In the event that, when checking the candles, they turned out to be wet, i.e. fuel is supplied normally, but the engine does not start, the problem may be as follows:
Failure of the ignition system: there is a characteristic carbon deposit on the spark plug electrodes (it is necessary to clean the candles with emery, after which they should be rinsed with gasoline and dried);
the size of the gap between the electrodes does not correspond to that specified by the manufacturer in the engine operating manual (the gap is adjusted by bending the side electrode to the required dimensions);
insulators for spark plugs or high-voltage wiring are damaged (defective plugs and wiring must be replaced);
the STOP button is shorted to ground (for normal engine start, the short circuit must be removed);
contacts in the angles of the candles are broken (contacts should be put in order);
the gap between the magnetic shoe and the starter does not correspond to the standard value (gap adjustment is required);
defects are found on the stator of the ignition system (the stator must be replaced).
Air leaks through the seals of the carburetor, spark plugs, spark plug heads and cylinders, as well as the carburetor and engine cylinder connections. If a leak is detected in the connections, it is necessary to tighten the fastening bolts, tighten the spark plugs and check the integrity of the gaskets between the plug heads and the cylinders.
Incomplete closure of the carburetor choke. To eliminate this problem, it is necessary to ensure free movement of the damper by checking the quality of the drive. If jams are found, they must be eliminated.
Compression and carburetor malfunctions
It so happens that the launch is carried out, but its process is significantly complicated. At the same time, the engine of the walk-behind tractor is extremely unstable and cannot develop power sufficient for normal operation.
The reason for this may be loss of compression, which can be identified by:
soot on the working surfaces of the valves, as well as the seats of the cylinder blocks;
deformation of the intake valve;
wear of the piston rings.
In order to restore compression, you must:
Check the technical condition of the engine timing mechanism, clean the parts contaminated with carbon deposits, and if there are any defects, replace them.
Check the condition of the piston rings and replace defective components.
If, during engine operation, black smoke comes out of the muffler, and an excess of oil is detected on the spark plug electrodes, or they themselves are covered with carbon deposits, this means that:
an oversaturated fuel mixture is fed to the carburetor;
the sealing of the carburetor fuel valve is broken;
the oil scraper ring of the piston is worn out;
the air filter is clogged.
To fix this problem, you should:
adjust the carburetor;
replace the leaky valve;
replace worn piston rings;
clean or replace a defective air filter.
In the event that, when the engine is running, light smoke comes out of the muffler, and the spark plug electrodes are dry and covered with a white coating, this means that a lean fuel mixture enters the carburetor. This problem is eliminated by adjusting the carburetor operation.
Units and components of motors that are installed on agricultural mini-machinery are exposed to significant loads. They can also fail during the operation of the unit, which will very quickly lead to serious failures.
If suspicious noises, jerks and irregularities in the operation of the walk-behind tractor systems are detected, it is very important to immediately turn off the engine, and then let it cool down - only after that it will be possible to fix the problem.
If, during operation, the motor starts to gain momentum on its own, i.e. is "running out", most likely this means that the fastening of the regulator and traction levers is loose. In this case, the user will have to readjust the motor control drive.
Sometimes, when the throttle is fully open, the engine does not accelerate when the throttle is pressed, but on the contrary begins to lose power until it stops completely. This is a clear sign of overheating, so the walk-behind tractor must be turned off and wait until its components have completely cooled down. After that, you should check the oil level in the crankcase, and also check the cleanliness of the ribbed surfaces of the blocks and cylinder heads.
Under increased engine loads, it can jam. There may be several reasons for this:
not enough oil in the crankcase;
a nadir formed on the lower head of the connecting rod;
the connecting rod or oil spray is completely out of order.
If the motor of the walk-behind tractor is jammed, it will have to be disassembled and the condition of the main units and components should be checked: faulty, deformed, melted, etc. subject to replacement.
What to do if the motor block motor works intermittently and does not develop the required power? There may be several reasons for this behavior:
Air does not enter the carburetor, which means that the fuel does not burn well - the filter will have to be cleaned or changed.
Fuel residues and combustion products form a thick deposit on the inner walls of the muffler, which must be removed.
In this case, the assembly will have to be removed, disassembled and properly cleaned all of its components. After that, the carburetor must be assembled and properly adjusted.
Wear of the cylinder-piston group.
Temperature and high loads do their job, and even the most durable metal wears out and deforms over time. Such parts should be replaced immediately, otherwise you can pay for this with irreparable damage in the engine itself.
Damaged ratchet housing or ratchet
The presence of this problem is indicated by the lack of movement of the crankshaft when the engine is started. To replace the clutch housing and ratchet, you will have to completely disassemble the starting block.
Loosen the screws securing the starter housing to the engine housing.
If the starter cord does not return to its original position, the starter motor must be adjusted. To do this, the screws are loosened and the position of the knot is set by hand so as to ensure the normal return of the cord.
A fairly common reason for the lack of a return stroke of the starter cord is the failure of the starter spring - it will have to be replaced.
The service life of any equipment is significantly increased by competent maintenance of its main units and components. The promptness of replacing worn-out spare parts is also of great importance. Therefore, in the event of the slightest malfunctions and malfunctions, they should be eliminated immediately - as a result, this will prevent much more serious and expensive problems.
VIDEO
If the equipment stalls during operation, you need to check how well the fuel is supplied:
The candle is taken out and viewed. It is overdried - this indicates a lack of fuel;
There must be enough fuel in the gas tank for the normal functioning of the machine;
The condition of the fuel cock is examined.It can be simply blocked off. Sometimes it is enough to open it for further use of the unit.
VIDEO Reconfiguration is done as follows:
The cover is removed, which protects the parts of the ignition system;
The engine flywheel turns until the contacts open in the magneto;
A special feeler gauge measures the gap from the "anvil" to the "hammer";
The flywheel turns until the piston is compressed. The latter must reach its peak;
The flywheel turns again until the characteristic knock, which will indicate the operation of the freewheel;
The flywheel turns in the other direction until the mark of this element coincides with the mark on the unit body;
The gap from the break contact to the cam is set at 0.3 millimeters;
The cam is fixed with a screw, which is located above the element, and the protective cover is installed in the equipment case.
If the above steps are performed correctly, the walk-behind tractor will not stall under load. When tilted, a vehicle may stall if there is not enough fuel in the gas tank. The unit must be installed straight, remove the starter rope. If the engine starts, you need to fill the fuel tank.
There are other issues worth considering:
The engine of the walk-behind tractor hits the return line. The reason is often the use of poor fuel. It will not be enough to replace the fuel. The pump and fuel supply hoses are flushed;
The technique works in jerks. The engine does not fully warm up. The motor must be turned off, wait for it to cool completely. Then restart it and warm it up for at least ten minutes;
The engine does not pull, therefore the engine power decreases. The filter system is checked and cleaned. The problem can be provoked by wear of the magneto ignition. In this case, the part is replaced.
Owners of both gasoline and diesel vehicles may face such problems. Regardless of the specifics of the breakdown, it is necessary to urgently stop using the unit and fix the problem.
Such problems can occur in the following cases:
Excessive engine oil in the fuel. The remaining fuel is drained, the fuel pump and hose system are flushed, new fuel is poured;
Incorrectly exposed ignition. It is necessary to check how correctly the gap between the electrodes is set;
The fuel in the engine cylinder does not completely burn out. In this case, it is necessary to disassemble the piston system, wash and dry the cylinder well, adjust the carburetor.
In the above cases, it is not difficult to repair motoblocks on your own. It is important to strictly adhere to the algorithm of actions.
If the equipment starts up and immediately stalls, this may indicate the following problems:
There can be a large distance between the electrodes, problems with contacts in the electronics, the spark plug is dirty. First, the candle is cleaned. After that, the integrity of the wires is checked. The normal distance between the electrodes is set;
The carburetor may be dirty, too little fuel is supplied. Sometimes it is necessary to change the fuel and reduce the amount of oil. The carburetor is dismantled, disassembled and thoroughly cleaned;
If the unit does not pick up speed, this indicates a lack of fuel. Gasoline can simply spill. The defect must be eliminated or the fuel tank replaced;
The walk-behind tractor does not develop speed if the gearbox breaks down. This is indicated by the presence of external sound from the gearbox.The malfunction is eliminated by replacing the oil with which the units are lubricated.
To fix the problem, you need to follow a certain algorithm. It is important to start the engine. To do this, follow these steps:
When starting the engine, the throttle trigger is squeezed halfway;
Do not regularly press the gas trigger, as this can provoke the engine flooding;
After starting the engine, you need to thoroughly gas the gas from half of the pressed trigger. After that, you can continue to work.
VIDEO
The classical design diagram of an agricultural unit consists of certain elements. These include the following nodes:
Fuel system - it consists of a carburetor, a fuel tank equipped with a tap, an air filter and a fuel mixture supply hose;
Manual or electric starter. The second option is typical for professional cultivators. The starter is used to untwist the main shaft by means of a special rope;
Cooling systems - starts to work under the influence of the rotation of the crankshaft and provides cold air through the speed of the flywheel;
Ignition system - generates and supplies a spark in the cultivator structure;
Gas distribution system - supplies fuel to the engine cylinders and allows the release of waste recycled fuel.
Understanding what the spare parts for cultivators are responsible for will make it possible to quickly identify the breakdown and fix it on your own.
VIDEO
Since the motor is most susceptible to loads, it is with it that most of the breakdowns of the cultivator are associated. The main symptom of a breakdown is a sharp loss of engine power. In this case, you need to check:
Is the motor warmed up, especially if the cultivator is used in winter;
The presence of dirt in the air filter;
The quality of the fuel used;
Serviceability of the ignition system;
The presence of residues of combustion products inside the muffler;
The presence of contamination in the carburetor;
Integrity of the piston elements.
If the motor fails to start at all, experts advise checking its position. The fact is that if the motor is tilted in relation to the central axis, then it will need to be set in its original position and check the quality of attachment to the frame.
In addition, it is required to check the amount of fuel in the tank and blockages in the tank cap.
All cleaning procedures performed are aimed at restoring the uniformity of the carburetor float immersion. To do this, it is also necessary to eliminate the deformation of the bracket, by means of which the float is attached to the piston system.
The dive setting is done with both open and closed needle valves. Use a screwdriver to align the bracket. All manipulations must be clear and accurate.
Along with the elimination of deformation, it will also be necessary to adjust the valves of the cultivator.
To do this, check the tightness of each of them. Performing this procedure allows you to restore the functions of the carburetor and return the amount of fuel consumed by it to normal.
VIDEO
The cultivator engine plays the most important role in the design of the machine. Often it will not start due to a malfunctioning fuel pump.
The pump serves to supply the fuel mixture to the carburetor at a certain point in the cycle. If no fuel is supplied, then the engine will not start. The pump is defective in the following cases:
If the fuel supply to the engine injectors is interrupted;
In case of fuel leakage as a result of mechanical wear;
The appearance of strange noises during operation.
To fix the damage, the pump should be disassembled and inspected. It is possible that the engine will not start on the cultivator due to dirt inside the pump. In this case, the device will need to be cleaned and reinstalled.
Motoblocks can significantly facilitate work on a personal plot. This is a compact agricultural machinery with high functionality and versatility. With its help, you can not only loosen the soil, but also carry out the basic activities for the care of plants and harvesting.
Like any other technique, walk-behind tractors sometimes fail. Fortunately, they have a relatively simple design, and you can even carry out simple repairs with your own hands. To do this, you need to learn how to determine which part of the walk-behind tractor is out of order, and what needs to be done to restore the operation of the equipment. Our article will help you with this, which not only describes the principle of operation of the walk-behind tractor, but also the main causes of equipment malfunction and how to eliminate them.
Most of the models consist of the same parts, so you can do the repair of the main components yourself.
Each walk-behind tractor consists of a base frame, a gasoline or diesel engine, a fuel tank, a rotor for attaching cutters, wheels and a bracket for fixing attachments. The most important component is, of course, the engine, on the successful operation of which the operation of the equipment will depend (Figure 1). In addition, modern models have fuel supply, cooling, ignition and gas distribution systems, and the occurrence of malfunctions in them can also lead to a shutdown of the unit.
The main function of the walk-behind tractor is to loosen the soil using special cutters that are attached to the frame of the device.
Note: Unlike a conventional plow, the cutter does not overturn the soil and prevents soil erosion.
In addition, the technique can be used to loosen row spacings in the process of growing agricultural crops, and special attachments are useful for harvesting. Simple models (cultivators) consist of several wheels and handles that are used to control the machinery. On the handles there are buttons necessary for control. More powerful and modern models are mini tractors without a cab. In this case, control is carried out by buttons and pedals located on the dashboard.
Despite the fact that walk-behind tractors are produced by a wide variety of manufacturers, it is customary to divide all such equipment into types depending on weight and power (Figure 2).
According to this criterion, walk-behind tractors are:
Ultralight - weighing up to 15 kg;
Lightweight (about 40 kg);
Medium - from 45 to 60 kg;
Heavy (over 60 kg).
As a rule, all types of equipment are supplied with an internal combustion engine with a capacity of 1.5 to 10 horsepower. This is necessary in order for even the ultra-light model to successfully cope with loosening the soil in areas with heavy and dense soils.
Since the main part of any technique is the engine, the main number of breakdowns is associated with it (Figure 3). In some cases, poor engine performance may be associated with poor-quality fuel or dirty air filter. There are also cases that the engine does not work properly due to insufficient heating, malfunctions of the ignition system, carburetor or pistons.
We will try to understand the main types of damage to the walk-behind tractor, which can be eliminated with our own hands. However, if you are not confident in your own abilities or are afraid that it is impossible to fix the malfunction on your own, it is better to contact a specialist.
If the engine does not start when you try to start, there may be a problem with the engine itself or its starting system.
To troubleshoot fuel supply problems, do the following:
Check the spark plugs: if they are dry, it means that no fuel is entering the engine cylinders. Such a malfunction can occur when blockages form in the gas tank cap, debris gets into the fuel supply system, when the supply valve is closed or the banal lack of gasoline.
Refuel the tank and try to start the engine again.
Check the fuel cock: if it is closed, it must be repositioned to open.
Clean the fuel tank drain hole.
Drain the gasoline tank, remove the fuel cock and rinse it with clean gasoline.
Remove the connecting hose near the carburetor and blow it out (together with the jets).
If all these manipulations did not help, and the fuel enters the carburetor, but does not enter the cylinder, then the malfunction is in the carburetor and this part must be carefully examined.
A common cause of carburetor malfunction is blockages. In this case, it is enough to disassemble the part, remove the source of pollution and reassemble. The instructions, which are necessarily provided by the manufacturer, will help you with this (Figure 4).
The main purpose of all manipulations with the carburetor is to adjust the immersion of the float, which is attached with a bracket to the piston system. It often happens that the bracket is deformed, the float does not sink correctly and the carburetor does not function properly. The bracket is adjusted with an ordinary screwdriver, both with the needle valve open and closed.
After correcting the carburetor, it is recommended to also check the serviceability of the valves. It is necessary to check the tightness of each of them and, if necessary, restore the optimal clearance.
It often happens that during the operation of the walk-behind tractor, extraneous noises appear in its gearbox. As a rule, this is due to an insufficient amount of oil in it, and to eliminate the malfunction, it is enough just to add fluid to the gearbox (Figure 5).
However, if there is enough oil in the gearbox and the noise persists, the brand and grade of oil may not be suitable for your model. In this case, the oil must be completely drained, the system flushed and refilled with new, more suitable oil.
In addition, extraneous noise may be associated with insufficient fixation of the transmission elements. They must be inspected and, if necessary, tightened. It should also be borne in mind that the gearbox elements must be inspected and replaced in a timely manner when the first signs of wear are detected. This way you can avoid more serious repairs in the future.
Engine malfunctions can occur both during start-up and during operation. In this case, it is imperative to check the spark plugs.If they are dry, there is a problem with the fuel supply, and if they are wet, the problem is in the engine itself.
One of the most common startup problems is the failure of the ignition system. To eliminate such a malfunction, first of all, you need to inspect the electrodes of the candles, and remove carbon deposits that could have formed on them with emery. After that, the candles are washed with gasoline and dried. Starting problems can also be related to incorrect electrode spacing. In this case, you just need to carefully bend them to the distance specified by the manufacturer.
In addition, ignition problems can be associated with damaged electrical wiring or spark plug insulators. These items are subject to replacement. Also, the lack of starting the engine may be associated with stator defects. Unfortunately, it is impossible to repair this part on your own and it will simply have to be replaced.
More often than not, the engine shows signs of malfunction directly during operation. This is due to the fact that small agricultural machinery is exposed to heavy loads and requires regular inspection and maintenance.
Note: If the walk-behind tractor began to move in jerks or make extraneous noises, it is imperative to turn it off, let the engine cool down, and only then proceed to the inspection.
Common problems in engine operation are:
An independent set of revolutions by the engine indicates that the control levers and linkage are loose and need to be readjusted.
When you press the throttle lever, the engine does not pick up speed, but, on the contrary, loses power. This indicates that the motor is overheating, so the technician must be turned off and wait until it has completely cooled down.
Interruptions in engine operation can be associated with a clogged air filter or muffler. The equipment must be turned off, cooled and the parts inspected to clean and remove blockages.
In addition, engine malfunctions can be associated with malfunctions in the carburetor or insufficient oil in it. In this case, the part must be disassembled, inspected and filled with new oil.
A walk-behind tractor with a diesel engine is more difficult to repair with your own hands than a gasoline one, since such a motor has a more complex design. As a rule, possible malfunctions and ways to eliminate them on your own are described in the instructions, so we will focus only on the most common ones.
Diesel engine malfunctions can be associated with such problems :
Clogged nozzle: the part must be removed, cleaned and reinstalled.Weak fuel injection pressure you can also adjust it yourself, using the instructions for the technique.Engine cranks too easily with starter: this indicates insufficient compression in the cylinder. To eliminate the malfunction, tighten all the nuts on the cylinder one by one and replace the gasket on its head. It is also necessary to inspect the piston rings, and wash or replace them if necessary.Malfunctioning starter motor can also cause malfunctioning of the engine. Most often, there are situations when the screws securing the starter housing to the engine housing are loosened. In this case, the starter cord will not return to its original position. To fix the problem, loosen the screws and adjust the position of the cord so that it easily returns to its original position (Figure 6).
In addition, malfunctions can be associated with wear on the starter spring. It is impossible to repair it, so the worn out part just needs to be replaced.
Video (click to play).
If you want to master the practical skills of DIY repair, we recommend watching a video that describes the main causes of equipment malfunction and how to fix them.
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