Trimmer forester 254 DIY repair

In detail: trimmer forester 254 DIY repair from a real master for the site my.housecope.com.

Trim repair is necessary when the device does not turn on or is not functioning properly. All owners of private houses and suburban areas are familiar with the problem of excessive vegetation, which is sometimes difficult to get rid of. As you know, progress does not stand in one place and new developments and useful inventions appear in all areas. This also affected agriculture. You no longer need to mow the grass with old inconvenient devices, modern gas mowers have come to the rescue, which are able to get rid of vegetation in the most inaccessible places.

The petrol trimmer can mow the grass even during cloudy weather. It is very simple to take care of the personal plot with the help of this unit, and any adult man can cope with this activity.

Despite their versatility, like any technique, trimmers tend to break and fail.

Not every person can do DIY repair of petrol cutters, because this requires the skills of repairing electrical appliances, but today we will try to figure out how to start the trimmer without a starter and how you can generally debug its work with your own hands.

Do-it-yourself trimmer repair implies the elimination of all problems that interfere with the normal operation of the unit. Among the most common are the following:

breakdown of the CPG (cylinder-piston group) of the engine;
the trimmer fails when trying to increase the speed of work;
breakdown of the ignition coil;
there is no connection between the motor and the gearbox;
there are extraneous sounds during work;
the engine cannot reach the required speed.

Video (click to play).

Engine CPG failure can occur due to poor fuel quality or wear of engine parts. As you know, the piston group is lubricated thanks to the oil that is added to the gasoline. In old oil, grease precipitates out, which makes the oil unusable. If you continue to try to start the trimmer, then you can ruin the engine in a matter of seconds, and this will entail additional costs for repairing the trimmer. This breakdown is considered the most expensive. To eliminate it, it is required to replace the piston group assembly, to be more precise, it may be necessary to replace the cylinder, rings, piston and oil seals. In such cases, it is unlikely that you will be able to do without additional help, if only you yourself are a master and know how to handle such a technique.

Do-it-yourself repair of a petrol cutter can be done if it starts up and runs at idle, but then chokes when you try to increase the speed of work. To eliminate this breakdown, carburetor repair or cleaning of the muffler or gas filter is required. At first glance, everything is quite simple to solve, but if after you clean the clogged trimmer parts, it does not work, then additional diagnostics may be required.

The main sign that the ignition coil has failed and trimmer repair is required is the absence of a spark on the spark plugs. It is very important in this breakdown not to rush to replace the coil, in most cases the cause of the breakdown is the lack of contacts, the switch button, which may have broken, or the problem is in the candle itself. It must be checked without fail, perhaps a current breaks through somewhere or there are gaps or carbon deposits.

If the trimmer motor cannot reach the desired speed, it is likely that the air filter is clogged or there is debris in the engine itself.The solution to the problem is clear right away - to clean the engine and filter, in some cases it may be necessary to replace the filter.

In the process of work, most trimmer users are faced with constant noise. If you hear a characteristic knock, as if on metal, then it is likely that the engine is overheated in the trim tab or fuel does not pass. To eliminate this sound, you need to fill up with gasoline or turn off the mower for a short time.

Do not exhaust the unit: if it constantly works for wear and tear, then its service life is dreamed of several times. If a knock is felt in the engine itself, then the reason lies in a malfunction of the piston, piston ring, in a worn out cylinder or crankshaft bearing. In order for the knock to disappear, you need to replace the failed part in the trimmer.

Sometimes it happens that the engine in the trimmer works normally, but the output shaft rotates very weakly or does not rotate at all. This is reflected in the fact that when the trimmer touches the grass, it stops working at all and turns off.

To resume normal operation of the mower, there are 3 main components that need to be checked, namely:

sleeve;
output cup;
flexible or rigid shaft.

The gearbox is a very important component, therefore, the repair of the trimmer in this case should be carried out by an experienced craftsman, and so that such breakdowns do not happen in the future, the gearbox needs to be serviced accordingly.

In addition to the above breakdowns, other malfunctions occur, for example, the power button sinks or the limiter disappears from the mowing head. You can replace the power button with a soldering iron, and the stopper can be wound with copper wire. Have you noticed that the line is broken or run out? It is enough to buy a new skein of the same diameter fishing line and, having disassembled the drum, wind it around the bobbin.

If you want your mower to work for a long time and without interruptions, then it needs to be serviced constantly, you can contact service centers or carry out diagnostics yourself.

To do this, you need to constantly check the rod bushings and change them if necessary, the same goes for the spark plug.

It is constantly necessary to fill the gearbox with special lubricant, partially disassemble the motor part and clean it of accumulated dirt. In most cases, this trimmer maintenance is carried out according to a certain number of hours worked.

Now you are familiar with how to repair gasoline trimmers without additional help. But it is worth noting that if you are not confident in your knowledge and skills, it is better to leave this business to professionals. Image - Trimmer forester 254 DIY repair

A petrol cutter (trimmer, brushcutter or petrol mower) is an extremely important tool in the summer, both for owners of private residential buildings and for those who like to grow their own vegetables, berries and fruits in the country. Killing weeds or trimming your lawn can all be done with ease with the trimmer. And much faster than if you use other methods.

Unfortunately, like any other technical device, the brushcutter sometimes breaks down. For example, the engine is not running or there are problems with the carburetor or starter, even if you periodically carry out maintenance of the unit: change the cutting line or teeth, fill it only with high-quality fuel and oil, and also constantly lubricate the gas trimmer gearbox. In order not to pay for repairs, which can cost you a pretty penny, you can study the brushcutter device and carry out the repair yourself.

Typical circuit, according to which manufacturers make their brushcutters:

The upper part is considered the main one - the main elements of the brushcutter are concentrated here: the starter, the carburetor and the engine;

The middle part is a rod, which is hollow inside and along which a cable is laid, connected at one end to the engine, and at the other end to a gearbox that drives the cutting line.Buttons are also located here, with the help of which the operator can control the petrol cutter. A belt is attached here to relieve the weight of the trimmer, which the operator puts on the body to make it easier for him to do his job;

The lower part consists of a gearbox and a cutting tool, covered with a special casing. This is done specifically so that the operator does not suffer from debris, glass and other dangerous objects that may be in the grass that have flown into him.

The most frequent breakdowns that occur during the operation of the unit are:

the engine does not work, the trimmer will not start;
the engine manages to start, after which it does not hold speed and stalls abruptly and for no reason;
the brushcutter bar vibrates strongly;
the gearbox is overheating;
low speed at the cutting line.

Before proceeding with the repair, study the instructions, which must be included in the kit so that correctly diagnose.

If the engine of the device does not start, you need to check for the presence of gasoline in the tank of the petrol cutter. Keep in mind that when you refuel your device with a specially prepared mixture of oil and gasoline, the fuel must be at least AI-92. A certain amount of oil is added to the pre-calculated volume of gasoline using a syringe to avoid engine damage. After making sure that the problem is not in the absence of gasoline, we proceed to check the operation of the ignition unit.

Troubleshooting the ignition unit we start with a candle. To check if it works, just unscrew it, bring it to the body and try to start the engine. If everything is in order with the candle, you will see a spark flashing between the body of the brushcutter and the candle.

Another source of trouble is that a mixture of oil and gasoline floods the channel into which the plug is screwed. Try drying the canal and drying and cleaning the candle itself. You need to leave the device to dry for about one hour, then screw the spark plug back in and try to start the engine. If fuel constantly floods the candles, you are unlikely to fix this kind of malfunction yourself, so you will need to contact a qualified specialist.

If you determine that the source of the problem does not lie with the ignition unit, it is time to check. condition of unit filters, fuel and air. The air filter will need to be replaced with a new one if, after removing the old filter, you find that the engine starts easily without it. To make sure the fuel filter is working, do the following:

disconnect the hose from the filter outlet;
try starting the engine;
if the fuel mixture begins to flow out of the filter hole, then everything is in order with it; otherwise, replace the filter.

The last reason the engine won't start could be a clogged breather or muffler. You should make sure they are clean. If not, clean the exhaust port or breather.

A carburetor is a rather complex element of a brushcutter that should not be repaired by an unprepared person on his own, with the exception of performing some simple operations, for example, cleaning the inner surface of the product from contamination without completely disassembling it. Adjusting the carburettor trimmer it is better to entrust it to specially trained people who will be able to carry out the finest adjustment without disrupting its normal performance.

The role of the reducer in the trimmer is to mediate between the motor and the line, transferring torque from the motor to the bottom of the machine through two toothed gears.

To prevent wear of gears in the gearbox and their premature failure, care must be taken to ensure that they are constantly lubricated. Most manufacturers indicate in the instructions supplied with the brushcutter that the gearbox must be filled with oil at least once a season.If you often and extensively work with the trimmer or hear unpleasant noises coming from the gearbox, check its condition and, accordingly, you will have to lubricate it more often.

To lubricate the gearbox, you need to do the following actions:

Find a plug on the gearbox, the role of which boils down to the fact that it closes the technical hole used to put a new lubricant;
Remove this plug using the special wrench supplied with the trimmer;
Use lubricants such as Litol-24, Oleo-Mas or ordinary machine oil. Apply them to the gears through the hole in the gearbox. In the process of performing the operation, slowly turn the gears to achieve uniform lubrication;
Tighten the plug on the gearbox and start the motor. Make sure that the extraneous noises that were previously heard from the gearbox have stopped.

If you hear from the gearbox hard knockingmost likely, the reason for this is that the bearings have worn out due to intensive operation, insufficient lubrication, or due to dirt entering them. There is only one solution in this situation - to replace the failed units.

If you find that the trimmer head has stopped working and is not rotating, the most likely cause of the problem is wear of gears, more precisely, their teethwhich are no longer in contact with each other and do not transmit torque from the motor. The malfunction is eliminated by disassembling the gearbox and replacing the gears with new ones.

On trimmers, in addition to electric motors, gasoline internal combustion engines are installed. This mechanism requires special attention to itself, since if it is incorrectly configured, it will either refuse to work, or it will work intermittently and loss of power. Basically, engine tuning is about adjusting the fuel supply, and this is done with the help of the carburetor trimmer.It is almost impossible to cover all types of carburetors produced by manufacturers of gas trimmers. But, since the design of this module, as well as its principle of operation, is largely similar between different models, a generalized description of the processes occurring in the carburetor can be made. This information will allow the user to understand the principles of operation of the device, to eliminate the malfunctions that have arisen and to operate it correctly.The carburetor trimmer is based on one-piece aluminum body... Below is a diagram of this block.At the bottom of it, there is a diffuser, which is also called Venturi nozzle (eighteen). Air is drawn in by the motor through this nozzle.The smaller this hole, the faster the air flows, and the higher the level of its vacuum in the zone with the smallest diameter.At the top of the diffuser are fuel channels (11.12). Through these channels, the air flow draws in gasoline. The fuel pump itself, the jets and the system used to regulate the supply of the fuel-air mixture can be built-in or installed externally.Throttle valve (9) adjusts the amount of air sucked into the carburetor. Its amount affects the power that the engine develops. The damper (7) is used for cold starting. It must be closed if you are going to start the unit. After the engine has started, it must be opened, otherwise, the engine will immediately stall.Impulse channel (1) connects the impulse chamber of the pump to the crankcase of the engine, namely, to its internal volume. The piston in the cylinder, making reciprocating movements, successively changes the pressure in the crankcase (vacuum or pressure increase). The pressure drops force the diaphragm (4) to move. Therefore, the operation of the pump is synchronized with the operation of the engine.The suction of gasoline from the tank occurs precisely with the participation membranes (4). Gasoline enters the carburetor through the union (2).Further, its path lies through the inlet valve (3), the outlet valve (5), through the mesh filter (6), the fuel channel (10), passes the needle (14) and fills the chamber (16), which has a control diaphragm (18) ...The valve (14) is connected to the diaphragm (18) by means of a lever (17). The cavity, which is located below the membrane, is connected to atmospheric air through the hole (19).The device operates as follows.

A vacuum is generated in the diffuser during the suction stroke. This fact causes air leaks. The position of the throttle valve (9) determines the amount of air entering the carburetor chamber, as well as the engine power and the number of its revolutions.

At this time, fuel is sucked in from the chamber (16) through the jets (11,12), after which it is mixed with the flowing air. Gasoline, mixing with air, begins to spray. Thus, a air-fuel mixture.

The finished mixture enters the cylinder, where it is compressed by the rising piston and ignited at its highest point from the spark generated by the spark plugs.

Since the volume under the control diaphragm (18) is connected to atmospheric air through the channel (19), the diaphragm goes up, opening the valve (14) by means of the lever (17). After opening the valve (14), a new portion of fuel enters the chamber (16).

After the chamber (16) is full, the diaphragm (18) returns to its original position and the valve (14) closes.

Further, when the motor is running, all the above processes are repeated. A screw (13) is used to adjust the amount of fuel entering the diffuser through the nozzles. The screw (15) is also used to adjust the idle speed. When the regulators are twisted, the fuel mixture is enriched, and when the regulators are twisted, the mixture becomes lean. Also, in some models of carburetors, you can adjust the idle speed of the engine. quantity regulator... It is usually located outside and, when twisted, abuts against a lever attached to the throttle shaft.Thus, using 3 adjusting screws, you can achieve maximum engine performance, as well as adjust its smooth operation at any ambient temperature, and even in mountainous areas.Failure of the trimmer carburetor occurs due to the use of poor quality gasoline, a damaged air filter and the accumulation of dirt in the chamber of this unit. Most often, it is quite possible to repair the carburetor with your own hands. Listed below are typical brushcutter carburetor malfunctions.A common malfunction that "haunts" the fuel pump is deformation of the pump diaphragm... For this reason, it does not fit properly and the pumping passages are not sealed.The reasons for membrane deformation can be the following:

long work of the trimmer;

use of unsuitable fuel;

ingress of gases into the impulse channel.

As a result, diaphragm damage reduces pump performance and, as a result:

depletion of the combustible mixture occurs;

it is difficult to start the engine;

there are interruptions in the operation of the motor;

the piston is damaged.

Also, the above-described consequences for the engine can cause clogging of the pump cavity with impulse side... In this case, dirt enters the membrane through the impulse channel.To clear the blockage, you will have to disassemble the carburetor and clean the membrane.The strainer can become dirty if contaminated fuel enters through a fuel hose or a defective pickup head. In the photo below you can see what a clean filter looks like and a dirty one (parts are separated by a line).Troubleshooting will require a thorough cleaning and rinsing of the strainer. Also recommended blow with compressed air all holes in the carburetor trimmer housing.This failure occurs when the contact surface of the lever wears out.The abrasion of the contact surface occurs due to the presence in gasoline abrasive particles or due to strong vibration of the motor during operation. This defect in the control lever causes problems with the intake, as well as improper idling of the engine.The inlet needle breaks down, as a rule, due to the presence of abrasive particles in the fuel fluid.

the tightness of the inlet needle seat is disrupted;

there is a leakage of a combustible mixture;

there are malfunctions in the engine operation associated with re-enrichment of the fuel mixture.

Also, the inlet needle may just jam.A jammed inlet needle can cause the presence of dirt in the fuel, or a long idle device without work.If dirt accumulates in the control cavity, the inlet needle cannot close the hole tightly and a lot of fuel pours into the chamber.It causes re-enrichment of fueland the engine starts to malfunction. It is necessary to disassemble the carburetor and clean the cavity of the control membrane.The membrane can undergo deformation during prolonged operation of the unit and when using aggressive fuels.Failure of normal adjustment due to a defect leads to:

damage to the piston;

difficulties when starting up;

depletion of fuel;

improper engine operation.

This problem can occur if the adjusting arm is not properly installed or if it is bent before installing. As a result, the contact surface is in the wrong position, which disrupts the additional fuel supply.The throttle and choke valves are mainly subject to wear due to the presence of abrasive particles in the air. Defective flaps look like they have been sandblasted.As a result of valve wear, engine performance decreases, malfunctions appear in its operation, piston rings, piston and cylinder coating wear out.The air and throttle shaft can wear out for the following reasons:

insufficient and improper maintenance of the air filter;

the air filter is damaged;

the air filter is not suitable for this unit.

Due to hit poor quality purified air, the shaft will wear out and may break. Broken shaft parts can enter the combustion chamber or crankcase and cause serious damage to the entire piston system.To eliminate problems with air purification, it is necessary to replace the defective filter or flush the existing (serviceable) one. The filter must be washed in soapy water and dried.Carburetor adjustment is necessary in the following cases:

the new engine was run-in (4-5 liters of fuel mixture were used);

the composition of the fuel has changed (brand of oil and gasoline);

the weather has changed (it became hot, cold);

the rarefaction of air has changed (applies to mountainous regions);

after long-term storage;

increased load on the engine (after changing tools, etc.);

due to vibration, the adjustment screws spontaneously unscrewed;

fuel consumption has increased, the carburetor overflows fuel;

carbon deposits quickly appear on the spark plug electrodes (while the fuel mixture is prepared correctly);

the engine starts and immediately stalls or gains momentum poorly;

gasoline does not enter the cylinder;

a large amount of exhaust gases.

Before you start adjusting the carburetor trimmer, you must do the following:

flush the engine;

replace or clean the spark plug;

change to a new one or clean the air filter (it is recommended to wash it in warm, soapy water, wring it out and let it dry well).

It is also necessary set cord a suitable diameter in the trimmer coil or install knives - this is done so that during the tuning process the engine has at least some kind of load. After installing the cutting tool and starting the gasoline engine, let it warm up for 10 minutes.If at idle motor, you notice that the cutting tool is rotating, so it is necessary to reduce the engine speed. This is done using the lower idle speed control, often marked with the letter “T”. The illustration below shows the placement of the adjusters on a Husqvarna trimmer.But, for example, on a Stihl trimmer, this screw may be marked “LA”.So, turn the idle speed control to the left until the trimmer head comes to a complete stop.To adjust the carburetor, 3 regulators (screws) are used.

Right adjuster L adjusts the level of enrichment of the combustible mixture at low speeds. It needs to be regulated first. Achieve maximum idle speed. This is done with the L knob by turning it left and right. After finding the point of maximum speed, return the regulator half a turn to the left (counter-clockwise).

Lower T adjuster (LA) used to adjust idle speed. Turning it to the left, the engine speed will begin to decrease, and turning the regulator to the right, the engine speed will increase.

Left Knob H is responsible for enriching the combustible mixture at high speeds. The enrichment setting completes the carburetor setting. Also, using this regulator, you can adjust the maximum speed, fuel consumption and engine power.

Important! If the engine is allowed to run at full speed for more than 10 seconds, it may fail.To eliminate this nuisance, adjustment will be required. With the engine running, give full throttle, then turn the regulator “H” to the right until the speed starts to decrease. After that, the regulator “H” must be slowly scrolled to the left until you hear the uneven operation of the engine. Then you should turn the knob “H” to the right until the moment when smooth operation of the motor is heard.After carrying out the above steps, the carburetor setting can be considered complete. After correct adjustment, the engine should confidently pick up speed, a little quarter at maximum speed, and when idling, the cutting tool should not turn. This manual is suitable for adjusting carburettors on Huter, Patriot and other brushcutters.There are also carburettors without screw, responsible for the enrichment of the combustible mixture at low speeds. That is, they have only 2 adjusting screws: an idle speed regulator and a fuel mixture quality regulator at high speeds. How to tune this type of carburetor can be found in this video.

The mass and piece production of trimmers is based on the use of generally accepted technology, a typical design scheme consists of certain elements and parts, it is important to know them when carrying out independent repair work:

top part. The basis of the entire structure, where all important elements are collected, such as a starter, a carburetor and a petrol cutter engine;
middle part. A hollow rod, inside it is a cable that connects the motor and the gearbox, which drives the cutting line. In this part there are fasteners for distributing the weight of the entire structure and a belt for fixing the trimmer on the belt of a person using the trimmer for its intended purpose;
Bottom part. It houses the gearbox and cutting elements, which are hidden under a practical cover to protect the user. The casing provides an increased level of safety, preventing large fractions of debris, stones and glass from entering a person while working with a petrol cutter.

Knowing exactly the internal structure and the principle of operation of the trimmer, you can independently carry out repair measures for the structure or replace individual components that have become unusable, using the repair instructions.

The most common and common failures of the unit that need to be corrected on their own include the following problems:

engine malfunction, due to which the brushcutter does not start and does not work;
increased vibration of the brushcutter bar, which complicates its intended use;
increased overheating of the gearbox, its accelerated heating during operation;
slow and weak functioning of the cutting line at insufficient speed;
clogging of the starter grille, causing overheating of the engine and its refusal to work;
fast and frequent clogging of the carburetor due to the use of low-quality fuel;
clogging of the air filter due to non-observance of the measures for the care of the device.

All these problems can lead to the fact that the device will lose its working capacity. Before ordering the necessary spare parts for the mowing, a visual inspection and diagnostics of the device should be carried out.

Particular attention should be paid to individual spare parts and units of the device, to check them you do not have to contact a professional master, a set of diagnostic measures will help you to identify the consequence of a loss of performance with your own hands.

If the trimmer motor does not start or stalls immediately after starting, when the gearbox overheats or during the operation of the device, extraneous noises are heard and vibration is clearly felt, it is important to visually inspect and identify a non-working unit.

To optimize the preparatory measures before repairs, you should carry out a simple diagnosis and check step by step:

the presence of fuel in the tank and lubrication in the main units;
serviceability of the spark plug and its performance;
the cleanliness of the fuel and air filter of the brushcutter;
clogging of the outlet channel and breather of the device;
the quality of the fuels and lubricants used.

To determine the functional efficiency of the petrol-cutter's ignition, it is necessary to determine whether the spark plug is working by testing the appearance of a spark when it comes into contact with the body of the functional device.

The spark plug itself can be replaced with a new one, having previously dried the candle channel, if necessary, the old element is also dried, cleaned with special devices and returned to its place.

In the process of inspecting the carburetor, it is worth paying attention to the possible leakage of the fuel used; to identify problems with the carburetor, the following measures must be taken:

purging the fuel hose to eliminate possible blockage of the element;
checking and replacing the gasket between the engine and the carburetor;
determination of tightness and maintenance of constant pressure in the unit.

If necessary, you can personally disassemble and thoroughly clean the unit using gasoline, the jet and channels are cleaned using compressed air.

The gearbox transmits torque from the motor shaft to the cutting tool, its gears during operation must be absolutely clean and always lubricated with special grease.

Carrying out a technical inspection on your own once a season will allow you to get rid of the need to repair the gearbox or replace it, with the purchase of an expensive new unit.

The starter is necessary to bring the trimmer into working condition, its diagnostics consists in checking the tension of the starter cord connected to the teeth of the starter coil, which are often destroyed during an abrupt start.

A non-working starter in a petrol cutter cannot be repaired; it must be replaced with a working unit as part of a mandatory technical inspection or a set of repair measures.

Video (click to play).

Cutting elements require special attention and care, which must always be cleaned of dirt and cut grass after use. Regular inspection and thorough preparation of the device for operation will help to avoid costly and time-consuming repairs, and always be confident in the performance of the petrol brush.