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» Repairing a lawn mower with your own hands: breakdowns and methods for eliminating them. Do-it-yourself grass trimmer repair, common causes of breakdowns Do-it-yourself trimmer gearbox maintenance

Repairing a lawn mower with your own hands: breakdowns and methods for eliminating them. Do-it-yourself grass trimmer repair, common causes of breakdowns Do-it-yourself trimmer gearbox maintenance

Trimmer repairs should be carried out as soon as possible when the first signs of breakdown appear, so that minor faults do not lead to more serious problems. All models are characterized by the presence of such main components and structural elements : drive system (motor), transmission devices, working part (knife or fishing line), belts and handles. Failure can occur in any part, but some components fail much more often than others.

Lawn mowers powered by gasoline or electricity (as well as different models from different manufacturers) differ in design and the nature of the problems. Some of them can be easily eliminated with your own hands, while others will require more overhaul or contacting the service center.

The most common breakdowns of brush cutters are associated with the following structural elements:

  • engine (in particular with a piston system);
  • carburetor;
  • barbell;
  • starter (rope break, spring breakage or disengagement);
  • with an ignition or fuel supply system;
  • transmission mechanism (gearbox);
  • filters and muffler.

Symptoms of malfunctions are as follows:

  • the appearance of uncharacteristic sounds when operating the lawn mower;
  • the lawn mower does not turn on, does not reach the required speed, or stalls;
  • when the engine is running, the working part does not rotate or skips;
  • gasoline leak;
  • excessive heating of individual components.

Smaller breakdowns can also occur, which are detected without any special diagnostics:

  • start button sticking;
  • limiter drop;
  • line break or breakage (loss of sharpness) of the knife.

Minor problems are easy to fix. Repair of a petrol trimmer in more difficult cases will require preliminary diagnostics to find out the exact reasons. If you have the appropriate knowledge and skills in plumbing, you can fix problems yourself by replacing failed parts.

Disassembling a gasoline scythe, lubricating its parts and replacing faulty elements

To disassemble the trimmer for carrying out repair work In general, the following devices will be needed:

  • a set of screwdrivers (with different tips) and wrenches;
  • small puller for removing bearings;
  • special spark plug wrench;
  • hammer.

In each case, you will need to disassemble individual components.

It should be taken into account that the starter (starter) in a number of models is non-separable - in this case, if there are problems with it, only replacing the element is possible. If the knot is disassembled, it can be repaired by removing and replacing the rope and spring, or installing the latter in place (when it comes out of engagement).

Disassembly and replacement of the rod

Quite often it is necessary to repair the trimmer rod. It is a structure made up of the following parts:

  • a steel drive shaft having polyhedral or square splines at the upper and lower ends;
  • aluminum tubes;
  • a plastic bushing designed to maintain the centralized position of the drive shaft in the tube (to prevent vibration);
  • a rubber shock absorber needed to connect the rod to the motor;
  • steering wheel with a handle used for steering, and a stand, a belt.

Some models have a shock absorber between the steering column and the bar. All control elements(lock lever, ignition switch, gas button) are located on the handle.

A conical cone is connected to the lower end of the rod bevel gear, but some lightweight models are available without it. This is due to the fact that their rod has a curved shape, and the shaft is a flexible cable.

How to disassemble the rod and then reassemble it to lubricate the shaft or replace it is shown in detail in the video below. In the same way, replace a broken rod with a new one.

It often happens that the multi-faceted or square splines of the drive shaft “lick”, while the working mechanism does not rotate or does so with over-slip. Then the shaft is changed.

When appears knocking on the phone, you should disassemble the rod and check the condition of the bushing, and if necessary, replace it. How to properly assemble the throttle handle on a trimmer is discussed in the video below.

If there is no intact rod suitable for installation, then you can tighten the fracture site with a clamp or apply something like a splint. This measure is temporary, so you should replace it as quickly as possible.

Clutch repair

When the knife or line spins almost constantly when the engine is idling, and uncharacteristic sounds come from the front of the engine, this indicates a breakdown of the clutch. The cause is a broken spring. In this case, the equipment mows normally.

If slipping occurs, then in addition the pads are worn out.

The trimmer clutch is repaired as follows:

  • remove the cover from the muffler;
  • remove the metal stand;
  • then remove the cylinder and starter caps to gain access to the clutch;
  • unscrew the side screws to remove the shock absorber cover;
  • remove the tube from it, having previously loosened the tightening bolts;
  • unscrew the clutch (shown in the photo below);

  • inspect the condition of the spring, pads and bearings;
  • a new spring is hooked by threading the hooks into the corresponding holes;
  • To replace the pads, you need to remove the spring, and then unscrew the bolts on them.

If necessary lock the crankshaft using, for example, a rope.

Repair of gasoline engine, carburetor and gearbox

Engine problems can be caused by problems with the piston system, oil seals, and rings. To eliminate them, it is necessary remove drive motor.

Determining what exactly caused the breakdown is not easy. If there is a warranty, you should take the mechanism to a service center for diagnosis and repair. If it is not possible to turn to specialists for help, then it should be taken into account that replacement is most often required piston rings. To do this, you will need to disassemble the engine and remove the piston. They do this in the following sequence:

  • remove the cover of the plastic case by unscrewing the screws or squeezing the clamps;
  • disconnect the rod with the crankshaft;
  • remove the cylinder head;
  • take out the piston and rings;
  • if necessary, replace them;
  • Reassemble in reverse order.

The rings should be installed carefully because they are quite fragile.

How the piston is installed and what happens replacing oil seals when carrying out engine repairs, this is clearly shown in the videos below:

With regular use, the trimmer may gearbox breaks. The gears and bearings wear out (they can also break). To prevent this from happening frequently, this unit should be lubricated regularly. The frequency is almost always indicated in the operating instructions for the model used (at least once a season). The video below can serve as repair instructions.

To lubricate the gearbox, you should unscrew the plug and simply squeeze out a suitable lubricant inside the assembly, turning the shaft.

You can only remove and clean the carburetor yourself, and also replace the gasket between it and the engine. It is quite problematic to determine the tightness of a unit at home. The main thing is to correctly assemble the equipment after repair so that the trimmer works without problems.

Common problems with electric trimmers

Electric trimmers differ from gasoline devices in a more simplified design. Conventionally, the electric scythe is divided into mechanical and electrical part . Accordingly, the same groups of problems that occur with this equipment are identified.

Most breakdowns cannot be visually detected. To do this you will need to use various devices. Visually you can determine the following:

  • the integrity of the power cable is broken (the insulation is torn off it, or it is clearly broken);
  • sticking or jamming of the start button;
  • mechanical external damage to the brush cutter;
  • problems with the cutting part;
  • stopping the scythe when clogged with grass;
  • plug damage.

To find out which part broke in other cases, you will need to disassemble the electric scythe and sequentially check the most likely options. At the same time, pay attention to external manifestations of deviations from the normal operation of the device. They help determine the cause.

Repairing an electric trimmer will require the following equipment and tools:

  • indicator screwdriver;
  • multimeter or tester;
  • soldering iron;
  • set of keys;
  • screwdrivers with different bits.

Electric scythes often do not work due to reasons not directly related to them, but caused by a decrease in the supply voltage in the network or the inoperative state of the outlet used.

How to disassemble and repair an electric scythe yourself

Before disassembling and repairing an electric scythe, you should check the condition of the outlet and the voltage in the network. If its value deviates from the norms specified in the operating instructions, then you should not even try to operate the device without stabilizer, designed for the corresponding power. Otherwise, the electric motor may fail. Only after determining that the cause of the trimmer failure is directly related to it, can one begin to disassemble the mechanism for repair purposes.

Disassembly and repair of electrical parts

Disassembling the electric scythe in order to repair its electrical part is carried out in the following sequence.


The brush and bearing units are shown in the photo below.

The scythe will work without thermostat, you just need to constantly check the temperature of the electric motor yourself, periodically letting it cool down. You can also install a new similar sensor.

The motor start button can be checked by shorting its contacts with a jumper. If the trimmer works, then the problem is clear. But this option is unsafe. Everything should be done carefully so as not to get hit electric shock. To change the button, you should use a screwdriver to remove it from its seat and connect the wiring from the old to the new. After replacement, you need to assemble the electric scythe and then check its functionality.

Replacing brushes required if they are destroyed. In this case, it is enough to pull out the old ones from the grooves and install new ones in their place.

The connecting terminals on different models of trimmers are almost identical, so connecting and disconnecting wires is done in the same way.

Bearing replacement is a rather difficult operation, because it can become stuck and not be removed from the motor shaft. It should be pulled or knocked down carefully so as not to damage the rotor or seat.

Bearing for trimmer ET1003A

When the trimmer motor fails and needs to be replaced with a new one, you should carefully remove the fan and bearings, and then install them in their original place. In terms of costs, replacement is almost comparable to purchasing a new mechanism. If you have no experience working with electric motors, it is better to entrust it to specialists.

Assembling an electric scythe

The instructions for assembling the electrical part of the brush cutter are as follows:

  • install the engine by tightening the mounting screws;
  • connect an electrical circuit;
  • lay the wires neatly between the individual compartments in the existing recesses;
  • close the top cover by snapping the locks and screwing it in place.

After assembly, the functionality of the device is checked.

Possible breakdowns in gasoline and electric trimmers enough. In order for the device to be operational for a long time, it should be kept clean and dry. An important point is carrying out regular preventive measures(for example, lubrication of the gearbox) and compliance with the operating rules set out in the instructions for the device. Buy better equipment High Quality from well-known manufacturers.

When disassembling the mechanism, it is recommended to photograph the process step by step so as not to forget anything, and during assembly not to miss a single detail. When replacing parts, you should pay attention to the selection of suitable components: it is better to use original spare parts.

For some models, the rod consists of two parts; a coupling is used to connect them. Such devices are convenient for transportation.

An indispensable tool for a modern summer resident or owner of a private home is a lawn mower, which allows you to effectively and efficiently put the surrounding area in order. The period of active use of brush cutters is from late spring to October. Modern units are equipped with powerful and durable internal combustion engines, reinforced transmission and main components. Despite this, physical wear and tear, manufacturing defects or improper operation lead to trimmer failure. In order to repair a trimmer with your own hands, you must have at least basic knowledge in the field of technology and some experience in its repair.

The main component of any gasoline tool is the internal combustion engine (ICE), which, through in various ways transmits torque to the executive body. In a modern lawn mower, an alloy rod (pipe) is used as a transmission element between the motor and the trimmer head, inside which the drive shaft is located.

Petrol trimmer Husqvarna

Thanks to the high-speed engine, the rotation speed of the fishing line can reach 13 thousand revolutions per minute, depending on the manufacturer of the braid. In order to avoid mechanical and thermal damage to the gearbox, a special hole is provided in its housing for introducing lubricant in the form of ointments. To make it easier for the owner, the headset long work All models of brush cutters are equipped with a durable shoulder strap.

Cutting part of brush cutter

Regardless of the manufacturer, almost every model comes with fishing line and steel knives.

Trimmer cutting part

The cross-section of PVC trimmer line can vary from 1.5 to 3.0 mm.

Made of durable polymer, during mowing it is subject to intense wear and, as a result, breakage. Therefore, from time to time it is necessary to check the presence of fishing line in the head and, if necessary, replace it. It is recommended to purchase an additional bobbin to quickly replace it with a reel that has run out of line.

Controlling a lawn mower

Types of lawn mower handles

Trimmers with internal combustion engines on the market today are equipped with a D-shaped, U-shaped or T-shaped handle, where the main controls of the unit are located. For example, on a U-handle braid, the throttle key and stop/start toggle switch are located on the right handle. In the D-shaped design of the handle, the gas adjustment key is located directly on the rod.

Trimmer malfunctions and how to fix them

Due to the presence of many components and parts, repairing a trimmer with your own hands involves eliminating breakdowns that interfere with its normal operation. The most basic malfunctions of gasoline scythes should be noted:

  1. The trimmer engine does not gain speed;
  2. Failure of the cylinder-piston group (CPG);
  3. Ignition faults;
  4. There is no connection between the internal combustion engine and the trimmer head;
  5. Mechanical knocks during operation of the unit.
  6. Repair of CPG lawn mowers

The main component of any internal combustion engine is the cylinder-piston group (CPG), which can fail due to wear of parts or poor quality of the fuel mixture.

Trimmer problems

Lubrication of rubbing units in a lawn mower is carried out by adding a certain proportion of oil to gasoline. This process can be disrupted due to old oil falling out as sediment. In this situation, when starting the trimmer, the motor overheats greatly and in a matter of minutes the most expensive breakdown occurs. To resolve the problem you will need complete replacement CPG, namely: piston, oil seals, cylinder and piston rings. If you are not an internal combustion engine repair specialist and do not have experience working with technicians, then it is unlikely that you will be able to fix the engine without the help of a specialist. You can find out more about the stages of repairing a piston trimmer here.

Trimmer ignition troubleshooting

When the ignition of a lawn mower fails, the spark on the spark plug disappears and, as a result, the fuel mixture does not ignite.

Spit spark plug design

In this situation, it is quite important not to rush to replace the coil, since the cause of the breakdown may be the lack of contact in the switch on the control handle.

An important point when troubleshooting the trimmer ignition will be the diagnosis of the cross section, where the distance between the side and central electrodes should be 0.5-0.7 mm. In addition, it is necessary to pay attention to the steel sealing ring on the spark plug, loss of integrity or deformation of which can lead to etching of air from the combustion chamber and, as a result, a decrease in the power of the scythe.

Ignition flywheel with coil

If replacement check electrical circuit, the spark plug and its contacts did not give positive results, then you should pay attention to the trimmer ignition module, namely the gap with the flywheel. Regardless design features and the manufacturer of the lawn mower, the distance between the ignition coil and the flywheel should be no more and no less than 0.2 mm. To restore the optimal value of the gap, you will need to loosen the coil mounting bolts and use a special measuring probe to set the trimmer ignition.

Gasoline trimmer fuel system

A clear sign of a malfunction in the engine power supply system is the absence of traces of the fuel mixture on the spark plug electrodes, which may be due to the following defects:

Components of the trimmer fuel system

  • due to a clogged hole in the gas tank, a vacuum is created, which prevents the normal flow of gasoline into the carburetor;
  • due to the poor quality of the fuel and the ingress of foreign particles, the fuel filter installed in the tank is clogged;
  • failure of the mixture to enter the combustion chamber as a result of carburetor clogging.

You can quickly determine the cause of the malfunction by dismantling the fuel hose leading to the carburetor. If fuel mixture flows out in a thin stream, then you should pay attention to the carburetor. If there is no jet, it is necessary to clean fine needle breather (small hole in the gas tank cap) or replace the fuel filter.

Carburetor repair

If fuel enters the carburetor, it must be cleaned or adjusted. Adjusting the trimmer carburetor involves restoring optimal mixing of the fuel mixture.

Carburetor trimmer with adjustment screws

To do this, pay attention to three adjusting screws: maximum speed (H), minimum speed (L) and idle speed (LA). To start setting, you need to completely tighten screws H and L and loosen 1 turn each. Then we start the scythe and let it warm up for 10 minutes to adjust the power system in operating mode. After warming up the internal combustion engine, press the gas button all the way (12,000 rpm). We restore the idle speed by unscrewing the LA screw. As soon as the trimmer head begins to rotate, you need to tighten the screw until it stops.

Gasoline scythe exhaust system

Trimmer Exhaust System

One of the frequent malfunctions of a lawn mower is the incorrect operation of the internal combustion engine, namely a drop in power when the speed increases (the mower stalls).

The reason for this work is that the exhaust system is clogged with particles of burnt oil. Manufacturers often make mufflers prefabricated and cleaning is quite simple. If the design of the spark arrester is non-removable, then it must be placed in water with detergents, and then dried with a regular or industrial hair dryer. Frequent clogging of the exhaust system indicates non-compliance with the proportions of oil and gasoline.

Repairing lawn mowers with your own hands: breakdowns and methods for eliminating them was last modified: June 25th, 2018 by Administrator

One of the main garden tools in the garden or at the dacha there is a lawn mower or trimmer. Gardeners use this tool for mowing grass, controlling weeds, and mowing the lawn. Like any other tool, a trimmer requires careful care and must be Maintenance Do-it-yourself lawn mowers.

Construction of a lawn mower

The trimmer consists of three parts: a gasoline engine, a rod with a shaft inside and a cutting element. Torque is transmitted through the shaft from the motor to the cutting head. In trimmers with a curved rod, the role of the shaft is performed by a cable. The rod itself is attached to the gearbox of a gasoline engine. The motor control is located on the rod; a belt can also be attached for convenient use of the trimmer. The cutting element in gas mowers uses a line wound around a trimmer head or a special blade used to trim large weeds.

The main and most complex unit in a trimmer is the engine. In household and semi-professional brush cutters, two types of engines are used - 2-stroke or 4-stroke. Depending on the type of gas engine, its refueling and maintenance differ.

  • 2-stroke engines do not have their own lubrication system, so they do not run on pure gasoline, but on a mixture of gasoline and oil. The latter, entering the combustion chamber, lubricates the moving components of the engine.
  • 4-stroke engines are lubricated by oil in the crankcase. They run on pure gasoline without impurities.

Do-it-yourself trimmer repair and trimmer maintenance can be done without outside help. If you need to replace engine parts or tune it, then you need to contact a repair shop.

First launch at the beginning of the season

Late spring, when it begins active use gas mowers, before starting work, you need to inspect and check the functionality of your tool. It is imperative to lubricate the rotating parts, inspect them and, if necessary, replace them. cutting elements(knife or fishing line). Check the presence of fuel mixture in the tank. If you drained the fuel at the end of the previous season, do not forget to pump fuel into the engine using a choke (if the engine has one).

If this is your first time using a trimmer, be sure to read the instruction manual. Such instructions should be included with each lawn mower.

Starting most two-stroke engines is quite simple. Use the procedure described in your trimmer's manual if it differs from the following:

  1. Move the choke lever to the "open" position. Place the trimmer on its side so that the air filter is on top.
  2. Hold or lock the throttle in the on position (the throttle should be held until the engine warms up).
  3. If the device has an on/off switch, move it to the on position (usually indicated by an "I" symbol rather than an "O").
  4. Make sharp, quick jerks with the starter handle until you hear the engine try to start. This should happen between 1-6 jerks, but no more.
  5. Close the throttle valve halfway and restart the starter. The engine should start after 2-6 additional pulls. If not, move the throttle lever to full position and pull the starter handle again. Return the lever to half throttle and pull 3 more times.
  6. After starting the engine, continue to hold the start button and allow the engine to warm up for 10 seconds, then disengage the starting system.
  7. When the trimmer warms up, it should restart with the throttle in the closed position.

You can also use another proven technique. If you remove the air filter before starting and pour a couple of drops of the mixture into the carburetor and reassemble it, the engine should start.

How to repair a lawn mower if the engine does not start.

Before repairing a lawn mower with your own hands, you first need to identify the problem. First you need to check the filters - both fuel and air. If necessary, the air filter can be washed in gasoline or with water and detergents.


Air filter

Afterwards the filter is wrung out well and dried. Before installing it on the air filter, it is advisable to moisten it with a couple of drops of oil for 2-stroke engines.
The fuel filter cannot be washed, only replaced.

Note. It is forbidden to leave the incoming gas pipe without a filter.

Checking the glow plug.

On a cold engine, remove the high-voltage wire from the spark plug and unscrew it using a special wrench. This key is provided by the manufacturer so that you can easily repair the lawn mower yourself.


Photo of unscrewing the glow plug

First, visually inspect it for contamination, and also check whether it is filled with fuel mixture. If the candle is dirty, it must be cleaned using a file or an iron brush. If the spark plug is flooded, it must be dried and the remaining fuel drained from the combustion chamber through the spark plug hole. Be sure to check the gap at the spark plug - it should be no more than 0.6 mm.


Crack in spark plug insulation

If cracks are visible on the ceramic part of the candle, be sure to change the candle.

Check for spark.

Insert the high-voltage wire into the removed spark plug and press the metal part of the spark plug against the engine body. This may be difficult to do because plastic cover usually closes the engine and the spark plugs are difficult to access metal case. You can use a bolt or something else to make contact between the spark plug and the housing. Turn on the trimmer and pull the starter cord. This can be difficult to do alone, so find someone you can trust to help you with your lawn trimmer repair!


Checking for spark

The spark should be blue. If it's hard to see the spark in the bright sunlight- Move the trimmer into the shade or indoors. If there is no spark, try changing the spark plug or high-voltage wire. If this does not help, you need to contact a repair shop.

What to do if the trimmer starts up and stalls.

Check the fuel tank air access valve. If the valve is clogged, a vacuum is created in the tank and the carburetor does not receive enough fuel. The trimmer will start, but then stall. Clean the valve. You can also start the lawn mower with the tank cap not fully screwed on. Check the fuel and air filter.

A lawn mower may also run unevenly or stall due to a poorly adjusted carburetor. How do you know it's a carburetor? — uneven operation of the engine or vibration during its operation. There could be a couple of problems here:

  • Poor idle speed control
  • Changed fuel mixture composition
  • Carburetor adjustment bolts have become loose due to vibration

Carburetor adjustment must be carried out with clean fuel and air filters and always in accordance with the instructions that come with the trimmer.
The engine is considered to be properly adjusted when:

  • A cold engine idles smoothly.
  • A hot engine has low speed without load.
  • The engine runs smoothly in any position.

Be sure to check the fuel line for cracks, leaks, and physical damage. If any are detected, the fuel hose must be replaced immediately.

Cleaning the mesh in the muffler

The exhaust muffler is equipped with a mesh - an anti-spark screen. Over time, this mesh becomes clogged, becoming covered in soot from burnt oil and reducing engine power output. This problem can be solved by cleaning the mesh with an old toothbrush. compressed air or a small wire brush.


Cleaning the mesh screen

As you can see, repairing a lawn mower with your own hands is not such a difficult task and many people can fix most of the problems.

Additional questions about servicing lawn mowers

Is it possible to leave fuel stored in a brush cutter?
No, fuel should not be stored in the unit. If the trimmer does not work for more than 30 days, drain the fuel and start the trimmer and let it run until the engine stops.

What type of gasoline should I use?
Most gas mowers run on 92-octane gasoline. Never use gasoline with a lower octane rating or diesel fuel. Try to use freshly purchased gasoline and mix it with the recommended oil for 2-stroke engines.

What is the correct spark plug gap?
The spark plug gap on all engines is 0.5 - 0.6 mm.

With frequent, intensive use of the brush cutter, the gearbox may begin to heat up or make sounds uncharacteristic of its normal operation, for example, grinding. This indicates that the mechanism needs to be lubricated. If this is not done in time, then more serious problems will arise (for example, the gears will wear out quickly and will need to be replaced), even jamming. Other breakdowns also occur with the transmission mechanism. You can repair and lubricate the gearbox yourself - to do this, you just need to familiarize yourself with the features of this work and stock up on some available tools.

The trimmer gearbox is a unit that transmits rotational movement motor shaft to a knife or fishing line. It is located at the lower end of the brush cutter rod. The transmission unit is also designed to reduce the trimmer engine speed.

Depending on the model of the brush cutter, the mechanism consists of several gears rotating at high speed. As a result, they heat up due to strong friction. If there is not enough lubrication, or there is none at all, then the process leads to severe overheating and failure of parts, and, accordingly, the need to carry out complex repairs. To prevent this from happening, the transmission unit should be lubricated in a timely manner. The disassembled gearbox is shown in the photo below.

Disassembled gearbox

Gearboxes of modern trimmers of different models from different manufacturers differ from each other in design and size seat. It happens:

  • round;
  • in the form of an asterisk;
  • square.

The most common diameters of round seats are 24, 25.5 and 26 mm.

Brush cutters are equipped with gearboxes with different types gears:

  • conical;
  • worm;
  • spiroid;
  • cylindrical;
  • planetary;
  • wave;
  • combined.

The drive shaft and gearbox are heavily loaded trimmer components that are highly susceptible to wear. Between them, motion is transmitted due to the interlocking of gear teeth located at different angles to each other. Effectively gear works only if there are no mechanical damages. In this case, the mechanism should not overheat, otherwise it may jam.

Main gearbox malfunctions and ways to eliminate them

Various breakdowns occur with the gearbox of an electric or gasoline trimmer. The most common of them are presented in the table below. There you can also find the causes of their occurrence and methods for eliminating them.

Gearbox malfunctionPossible causes of failureRemedy
the transmission unit gets very hotuse of inappropriate (poor quality) lubricant or its absenceneed to replace or add lubricant
The gears are new and not worn inTo break in, you should work for a short time without heavy loads with regular stops so that the mechanism has time to cool down
shaft jamming during rotation, backlash and knockingdestruction or significant wear of any of the bearingsreplace the failed bearing with a new one
the transmission mechanism flies off the mower bar or wobblesdamage to its bodypart needs to be replaced
in some cases, with minor damage, a clamp made of metal is used to tighten the area with the fracture
does not fit on the pipewear of the docking pointyou can make a winding of insulating tape at the attachment point or change the rod
the output shaft with the knife does not rotate or stops if the load increaseswear of teeth on gears or one of themreplacement of the interacting pair of worn parts is required

Bearings fail due to the use of inappropriate lubricant or lack of lubricant. They are also damaged by harsh operating conditions brush cutters and the ingress of foreign particles of material (for example, broken metal teeth of mechanical gears) due to the fact that the integrity of the anthers is broken.

To remove the bearing, you need to disassemble the gearbox and use special puller. If it is not there, then you can try to do it with a hammer with an adapter. In this case, you should work carefully so as not to damage the seat. It is not recommended to use the preheating method to remove the bearing. This is due to the fact that the metal may lose the required performance characteristics.

If the knife stops rotating under load or even stands still, this is accompanied by an uncharacteristic sound.

Most gearbox problems can be easily fixed with your own hands. It is recommended to purchase replacement parts that are “original” and intended for the model of brush cutter used.

Trimmer gear lubrication

Lubrication of gears must be carried out regularly in accordance with the recommendations outlined in operating instructions the model used. This should also be done if:

  • new gears were installed;
  • atypical sounds come from the gearbox during trimmer operation;
  • The knives are difficult to rotate.

In addition to the gearbox, the trimmer shaft also needs to be lubricated regularly. This is the norm proper care behind the device.

With constant use of the trimmer, its transmission mechanism experiences stress from grass, dirt adhering to the blades, or due to changes in torque. You need to choose a high-quality lubricant to extend the life of the gearbox.

Types of lubricant used

When choosing a lubricant, the following factors must be taken into account:

  • degree of adhesion of the composition to the metal of the assembly;
  • product brand;
  • lubricant consumption by the transmission mechanism.

Well-known manufacturers, e.g. , Stihl, Husqvarna and others, in addition to trimmers, also produce lubricant for them. Such products not only reduce wear, but also protect the gear metal from corrosion. Therefore, for brush cutters from these brands, it is better to use their own lubricants.

If the composition used for lubrication has good adhesion, then it is practically not squeezed out of the gearbox through the gaps.

Different models use lubricant differently. This is determined to a large extent by the intensity of use of the brush cutter and the heating of the transmission mechanism. It is considered that the lubricant is sufficient if the temperature of the gearbox during operation does not exceed40°C.

By consistency, lubricants for trimmers can be:

  • liquid;
  • semi-liquid;
  • hard;
  • plastic.

In terms of composition, they are in demand the following types lubricants:

  • graphite, significantly reducing friction, as a result of which gear rotation improves;
  • lithium, which are also an excellent anti-corrosion composition, saturated with additives that increase the wear resistance of the metal without harmful substances;
  • universal, containing highly purified mineral oils and performance-enhancing components.

Examples of suitable lubricants are: Champion EP-0, Gear Grease OREGON, Oleo-Mas, Azmol 158, Litol -24. You should also pay attention to manufacturers' advice on this issue and use the materials they offer. You can buy them at specialized retail outlets.

Champion EP-0 universal lubricant 120 g

Algorithm for self-lubrication of the gearbox

To carry out lubrication of the transmission mechanism, its preliminary no disassembly needed. The device already has a special hole for these purposes (it is shown in the photo below). In addition to gears, when lubrication, you need to pay attention to the following elements of the mechanism:

  • bearing unit;
  • flywheel and starter coil pawl.

Lubricant injection hole

Fill in oil or add solid lubricant through a grease fitting closed with a screw. In this case, perform actions in the following sequence:

  • clean the gearbox housing from dirt and adhering grass, especially carefully the area around the plug so that debris does not get inside the mechanism;
  • using the appropriate tool (often it comes with the trimmer), unscrew the plug;
  • the selected lubricant is injected into the open technological hole from a tube or using a syringe, as shown in the photo below;
  • screw the plug into place.

Gear Lubrication

When applying lubricant, you need to rotate the knife so that it is evenly distributed over the teeth of the moving gears.

If for any reason the gearbox needs to be disassembled, then the old lubricant must be completely removed from the entire surface of the gears, housing, and shaft, and only then a new one must be used. It is convenient to lubricate the disassembled mechanism with solid compounds.

The entire gearbox lubrication process is demonstrated in the video:

The transmission unit must be lubricated at least once a year, but it is recommended to do this every 20 hours of intensive use of the brush cutter. If the first signs of malfunctions with the mechanism appear, you need to add lubricant as quickly as possible.

How to replace a trimmer gearbox: algorithm of actions

To replace the gearbox with a similar part from the same manufacturer, it must first be disassembled and removed from the rod. They operate according to the following algorithm:

  • loosen the coupling bolts located under the transmission mechanism;
  • Using pliers, remove two corkscrew rings;
  • using a puller, pull the bearings from the driven and drive shafts;
  • then assemble the mechanism into reverse order installing all spare parts.

The disassembled transmission mechanism is shown in the photo below.

Disassembled gearbox

If you don’t have a puller at hand, you can try carefully knock down the bearings. When they are stuck and do not budge at all, you can heat them with an industrial hair dryer (at a temperature of 600°C) and remove them.

Assembling the transfer unit is easier than disassembling it. It may only take a light tap with a hammer to seat the parts into place. After assembly, be sure to check that the driven shaft can be turned by hand.

When there is a need to replace the transfer unit with a non-original part, then it should be taken into account their interchangeability. The following should be taken into account:

  • rod diameter (this parameter is often 25.4 or 26 mm);
  • parameters of the drive shaft - the shape of the connecting point and the diameter (its common value is 8 mm);
  • option for securing protection.

If the considered parameters match, then it will be possible to install a part from other models.

Timely lubrication of the gearbox will ensure its long-term operation without repairs. Besides, modern materials They protect the metal well from corrosion and increase its wear resistance. When choosing, preference should be given to the lubricant recommended by the manufacturer of the trimmer being used. If it is not possible to purchase such compositions, then the considered or other analogues suitable for their properties should be used. When it is necessary to disassemble a mechanism during repairs, this should be done carefully so as not to damage individual parts.

The presence of a gasoline trimmer significantly simplifies life for those who often have to mow the grass around the house or in the garden, as well as make hay for animals. However, the simplicity of operation does not exclude the occurrence of malfunctions; moreover, the complexity of the mechanism entails the difficulty of repair. And service maintenance imposes additional costs on the instrument.

In order to extend the service life of the tool, it is necessary preventive actions. For example, you should not overload the device; every time after 15 minutes, take a 10-minute rest. Do not neglect the operating rules and do not mow grass that exceeds the permissible height. If a breakdown occurs, do not rush to contact service department, inspect the device to identify the cause; perhaps you can actually repair the gasoline trimmer yourself, especially if you have some skill in working with equipment.

First, let's find out how to independently find the cause of a device malfunction, then we'll talk about why these breakdowns occur and how to fix them.

How to find a breakdown - symptoms

Although a petrol trimmer is complex device, some breakdowns can be found and easily fixed without help service center or master.

Here are a few ways to diagnose a breakdown at home:

  • First, check the spark, since without it there will be no ignition. If there is no spark, then the problem is in the spark plug, or in the ignition itself;
  • Also, if the spark plug is dry, then the fuel supply probably needs repairs or carburetor cleaning;
  • If the spark plug is filled with fuel, wipe it dry and try starting the tool again;
  • If everything is in order, but the tool does not work, then most likely the problem is in the engine. If you do not know how to repair this part of the tool, then it is better to take the gasoline trimmer to a service center.

Of course, we all want to save money on the services of a specialist, but do not forget that they charge money for unique knowledge and experience that allows them to fix the trimmer with a 100% guarantee.

Frequent malfunctions

If you make a list of breakdowns that owners most often encounter petrol trimmers, then it will turn out like this:

  • Engine;
  • Carburetor;
  • Broken rod;
  • Calm;
  • Starter;
  • Fuel supply;
  • Air filter;
  • Muffler;
  • Gearbox.

Below we will try to help those who want to repair a gasoline trimmer with their own hands, using available tools.

Check the spark plug of the petrol trimmer - is it dry or filled with fuel?

Causes of breakdowns and repair methods

If, for example, the tool stalls immediately after starting or does not start at all, then pay attention to the ignition system:

  1. Turn out the spark plug. If there are traces of a gasoline-oil mixture on it, it means the problem is caused by carburetor adjustment. Violating the cold start rules in the form of pumping up fuel also leads to the spark plug sticking, and the low quality of the gasoline used leaves a thick layer of black soot. In these cases, this part will need to be replaced. If the spark plug is dry, then the malfunction is related to the fuel supply.
  2. The accumulation of dirt in the gas tank leads to supply hose clogged. Disconnect it - if fuel does not flow, then the fault is in clogged filter or breather, which is cleaned with a needle, but the first one needs to be completely changed from time to time to avoid complications. It is advisable to do this every 3 months.
  3. In addition, gasoline trimmers often require replacement air filter, because if it becomes clogged, the fuel mixture is not rich enough.
  1. Another cause of a malfunction of a gasoline trimmer may be muffler when soot accumulates in it. To eliminate such a malfunction, you can dismantle the part, wash it in kerosene or burn it with a burner. In general, before buying a trimmer, it is advisable to get acquainted with the chosen tool through reviews of other people. Most models have weaknesses. This will allow you to protect yourself from a “pig in a poke” and prepare in advance for possible breakdowns.
  2. There are often cases when, during operation, extraneous noises such as whistling and strumming are heard in the lower part. This indicates a risk of failure gearbox. Disassemble the housing and pay attention to the space inside the part, if there is no oil there, most likely this is the problem, lubricate the moving parts. If the action does not have the desired effect, then you will have to change the transmission gears or bearings. You can inspect the degree of wear right away, so as not to disassemble the tool several times.

In order to ask as little as possible how to repair the engine, carburetor or gearbox of a gasoline trimmer with your own hands, do not purchase less common models, because It will be extremely difficult to find parts for them, and prices from official dealers do not always correspond to the capabilities of buyers. If you are new to working with complex technical products, then it is better to contact the service department for help, because... Self-adjusting the carburetor, for example, can subsequently lead to combustion of the entire piston system. In addition, some parts cannot be repaired at all, and the entire unit must be replaced, manually repaired in in this case won't make sense. Also, do not rush to open the instrument body if it is under warranty.

To help, we can suggest you contact the services of a trimmer repairman, who can be found on one of the sites, for example, profi.ru - LINK (don't forget to select your city). At least, if the tool is repaired by a master, you can be confident in the result.

New petrol trimmers

If you can’t repair a gasoline trimmer yourself or it’s too expensive, then you should think about buying a new model, especially since today you can buy tools not only from European brands, but also inexpensive Chinese models. We have selected and made a selection of gasoline trimmers in different price categories from Aliexpress (only good ratings) and from several popular online stores.

Trimmer Power Website Price
Sturm! BT9126BL 850 W Aliexpress