Stihl Fs 55 Lawn Mowers Carburetor Adjustment

Refueling

Stihl Fs 55 Lawn Mowers Carburetor Adjustment

The lawn mower is powered by gasoline, which is highly flammable. Therefore, do not smoke in the vicinity while refueling. The engine turns off before refueling. Such manipulations should not be carried out while the engine is NOT cool, as fuel may overflow and start presenting a fire hazard.

The fuel filler lock should be opened with extreme caution, as excessive pressure can cause fuel to splatter. The Stihl FS 55 lawn mower, the user manual of which you must read before using the device, is refueled in a well-ventilated area. If fuel is spilled, the device should be cleaned of it immediately so that it does not come into contact with clothing, otherwise the latter should be changed immediately.

After refueling is complete, tighten the screw lock on the fuel tank. This will reduce the likelihood of its unscrewing due to engine vibration. If this is NOT provided, there is a danger of fuel leakage. Important Pay attention to leaks. If fuel is spilled, the engine does not need to start, otherwise there may be a risk of burns.

Guidelines for holding and guiding the device

the lawnmower must be held securely with both hands. The operator should maintain a stable position while doing this. You need to grab the handles with both hands. For sale Lawn mowers with a round handle are presented, while the left hand should be on a hill, and the right hand should be on the operating handle. If there is a danger of an accident, the motor must be turned off immediately. The engine should run flawlessly when idling. The cutting tool must NOT rotate after releasing the throttle.

The idle setting needs to be monitored and adjusted from time to time. If the cutting tool continues to rotate at idle speed, the unit must be returned for repair. When guiding the scythe, you must pay attention to obstacles in the form of tree roots and stumps. It is necessary to work while standing on the ground. Do not use a ladder or lifting work platform.

Repair instructions

Lawnmower “Stihl FS 55”, the operating manual of which is supplied in the kit and must be studied by you before starting work, is a high-tech equipment that is not difficult to maintain. You can carry out repairs and adjustments yourself. As for the carburetor, it’s a matter of 5 minutes.

The main problems of a malfunctioning carburetor can be breakage and blockages. In order to find out the cause, Unscrew the fuel filter cap and remove the strainer. If dirt has accumulated on it, then blowing or flushing in gasoline will help. If you find Visible changes on the filter, then it should be replaced with a new one.

The fuel supply pipes may also be damaged. Failure to operate the carburetor starting device may occur due to clearances. Gasoline or acetone is used for flushing. The carburetor can be purged with compressed air using a convenient repair practice. The outlet or inlet pipeline, as well as the throttle body and those places where the carburetor parts are connected, may be depressurized. If you are faced with the aforementioned problem, then you can make sure of it with the help of a soap solution, which is applied to the desired area.

Model Description

The above equipment option costs 13,490 rubles. It is a premium device. With its help, you can take care of the territory on a large suburban area. Young and old grass, reeds and weeds, as well as young shrub growth are amenable to the equipment.

Lawn mowers device

You should be aware of the Stihl FS 55 lawn mowers device if you plan to operate the equipment, and even more so to repair it. The internal combustion engine in this unit is almost the same as in the chainsaw. However, the tire is last fixed to the engine reducer by a long tubular rod. A shaft is located inside, which transmits the torque from the engine to the working tool. This design is suspended on a belt, which is thrown over the shoulder. This allows you to keep the tool suspended, which is important with the sensitive weight of the chainsaw.

A handle is fixed to the Bar of the unit, with the help of it you can move the end of the bar with the working tool. the Stihl FS 55 lawn mower, the repair instructions for which are presented in the article, has a protective shield in the form of a casing on the human side, which excludes injuries during operation. The tool itself is a round drum with thick line coming out of the holes on both sides. When the drum spins, the line stretches under the action of centrifugal force and hits the grass, chopping it.

Lawnmower “Stihl FS 55”, the technical characteristics of which will be presented to your attention below, has a quick-wear nylon line. It is periodically renewed by unwinding the coil inside the drum.

Specifications. Operating instructions: safety measures

The equipment described above must be used by wearing special clothing and using the equipment. Clothing does not have to interfere with work. You should choose one that fits well to the body. It is necessary to exclude wide sleeves that could catch on bushes, wood or moving parts of the unit.

It is important to remove ties and scarves. This also applies to jewelry. Before starting the Stihl FS 55 lawnmower, you must wear safety boots, which have a rough sole. It is important to use a special protective helmet and goggles, which will exclude damage to the organs of vision.

Carburetor adjustment

The carburetor for the Stihl FS 55 lawn mowers can be easily adjusted independently. To do this, the filter should be cleaned following the maintenance rules prescribed in the instructions. The carburetor is adjusted with adjusting screws, there are three of them:

  • Lower;
  • Left;
  • Right.

The latter adjusts the fuel mixture for low revs. You need to find the maximum idle speed. To do this, the right screw is turned in both directions. In order to carry out the adjustment, the screw must be returned counterclockwise by a quarter of a turn.

When adjusting the Stihl FS 55 lawnmower, you must also use the lower screw, which is responsible for adjusting the engine. If you return it clockwise, you can achieve an increase. Correct idle speed control is characterized by normal hot engine rpm, stable cold engine operation and large trim head rpm reserve. At the same time, the engine continues to run stably even when changing position.

Adjustment of the carburetor of the Stihl FS 55 lawn mowers involves the use of the left screw. It regulates the mixture at high revs. It is necessary to deal with this screw in the last turn, because the adjustment of maximum revolutions, gas consumption and temperature, as well as engine power, depends on it.

Engine starting

The engine is started at a distance of 3 m or more from the place where the device is filled with fuel. These works cannot be carried out indoors. Before starting, you need a stable, secure position. In this case, the motorized device is held as firmly as possible. The cutting tool must NOT come into contact with the ground or objects, as it may rotate when started.

The unit is serviced by only one person, while unauthorized persons are not required in an area with a radius of up to 15 m. Otherwise, you may be injured by thrown objects. Starting the engine lawn mowers “Stihl FS 55”, the characteristics of which are presented in the article, and should not be carried out by hand. After releasing the throttle lever, the cutting tool will coast for some time. Flammable materials must be kept away from the hot gas stream and the surface of the hot muffler, as this could cause a fire.

READ  How to Repair a Stihl 180 Chainsaw

When adjusting the carburetor of the household trimmer is required?

Adjust the built-in trimmer carburetor when:

  • Running in a new engine, during which 4 to 5 liters of fuel mixture were used;
  • Sudden weather changes;
  • Changes in air pressure. for example, when the lawnmower is often used in mountainous areas;
  • Long-term simple trimmer;
  • The loads on the power unit of lawn mowers are growing rapidly;
  • Arbitrarily unscrewing the built-in adjusting screws of the carburetor. this becomes a prerequisite for increased vibration of the internal combustion engine;
  • Changes in the quality of the components of the fuel mixture;
  • Overflowing fuel with a carburetor, resulting in an increase in fuel consumption;
  • The regular appearance of a thick layer of resinous deposits and carbon deposits on the surface of the electrodes of a standard trimmer spark plug;
  • Starting the engine and turning it off arbitrarily or slowly accelerating;
  • Lack of fuel flow into the cylinder of the power unit;
  • Increase in the volume of emitted exhaust gases.

The lack of timely adjustment of the carburetor threatens a serious breakdown of the trimmer, up to the complete failure of its factory engine.

Carburetor for trimmer: device, do it yourself setting

Stable and efficient operation of a household trimmer largely depends on the quality of the fuel used by its operator. The filled fuel mixture must be enriched with air. therefore, the built-in carburetor is responsible for this in the basic device of the lawn mower. This knot is one of the main elements of the streamer, so the operator must constantly monitor its serviceability and settings. Otherwise, the trimmer will lose its performance and may completely fail.

Lawn mowers carburetor device

The standard design of any gasoline trimmer necessarily includes a fuel system, the basis of which is the action of a regular carburetor. Its structure and initial principle of operation are almost the same for all lawn mowers, regardless of their design features and purpose.

The lawn mowers carburetor consists of an all-metal aluminum case, which protects the internal components of the unit from moisture, small debris and dust. In the lower part of the body there is a built-in diffuser, the second name of which is “Venturi nozzle”. The main function of this standard part is to supply air in the amount required by the fuel unit to enrich the fuel. The diffuser works according to a simple principle: the smaller its diameter becomes, the more intensively the air is sucked in. This is due to the fact that in the area of ​​the smallest diameter, the level of air vacuum becomes maximum.

The upper part of the built-in factory diffuser is pre-equipped with fuel pipes through which, under the influence of air, the fuel mixture is drawn in. The rest of the carburetor parts: standard adjusting screws and a fuel pump, can be located both inside and outside the carburetor.

The lawn mowers carburetor device includes a throttle valve, the main task of which is to regulate the volume of intake air. The larger the amount of air, the higher the rated power of the trimmer power unit. Another function of the damper is to facilitate cold starting of the engine. If this is the first time the mower is started after a long period of inactivity, the shutter must be closed. Immediately after starting the engine, the part must be opened, otherwise the internal combustion engine will stall.

The carburetor for the trimmer is equipped with an impulse channel, which connects the internal cavity of the engine crankcase with the impulse chamber of the pump. The piston located in the engine cylinder creates reciprocating movements, which leads to gradual changes in pressure inside the crankcase. At the same time, the membrane is set in motion. Thus, the action of the pump is fully synchronized with the operation of the power unit.

The diaphragm of the standard carburetor takes an active part in the suction of fuel. It enters the fuel unit through the fitting. The fuel then flows through the built-in intake and exhaust valves, then through the strainer and fuel pipe. The fuel then flows next to the needle and gradually fills the chamber equipped with the control diaphragm.

The standard carburetor trim valve is connected to the diaphragm using a lever. Below the built-in membrane there is a cavity into which air is sucked in through a special opening.

The lawn mower carburetor works on this principle in stages. This ensures continuous operation of the fuel unit and uninterrupted fuel supply to the cylinder of the standard power unit.

DIY lawn mowers carburetor adjustment

Periodic adjustment of the trimmer carburetor should be performed on a fully serviced power unit. Before starting the procedure, the operator must thoroughly rinse the internal combustion engine parts and inspect its CPG for burrs or other defects. In addition, you will need to clean or change the spark plug, as well as rinse the filter elements in the lawn mower design.

The lawn mower engine must be running under a certain load when adjusting the carburetor. It is best to install a cord of the appropriate diameter or cutting knives on the trimmer.

After installing the cutting elements, the operator should start the internal combustion engine of the trimmer and leave it to work for about 10 minutes. If, during the operation of the power unit at idle, it was noticed that the cord or knife rotated, then it is necessary to lower the speed created by the motor. To do this, it is necessary to return the lower adjuster, often denoted with the letter “T”, to the left side, at a complete stop of the installed cutter.

Further configuration of the fuel assembly is as follows:

  • The “L” regulator, located in the case, is responsible for enriching the fuel mixture with air when the engine is running at low revs. The position of this screw must be adjusted first. To do this, the operator will need to achieve maximum engine speed when idling. to do this, turn the screw “L” alternately to the right or left side. As soon as the maximum speed is reached, the screw will need to be returned 1/2 turn to the left;
  • Screw “T” or “LA “is required to adjust the idle speed. While turning it to the left, the speed of the power unit will decrease, and when turning to the right, it will accordingly increase;
  • The “H” regulator, provided on the left, is responsible for enriching the fuel mixture with air when the internal combustion engine trimmer is operating at high rpm. This screw is also needed to adjust the engine power and the amount of fuel consumed. Adjustment of its position is carried out by turning the screw to the right or left side to achieve the maximum permissible engine speed. After that, the screw “H” will need to be returned 1/2 turn to the left.

The alternate execution of THESE actions will allow you to correctly configure the fuel trimmer unit, without the risk of exceeding the permissible load on its main working mechanisms.

Adjusting and repairing the carburetor lawn mowers

The trimmer does not belong to complex household appliances, therefore, most of its breakdowns are mechanical in nature and are quite successfully eliminated with their own hands. Even if the engine fails for serious reasons. damage to the piston ring, for example, repairs are reduced to replacing a part.

But even with a simple design, such a part of the device as a carburetor needs adjustment.

Signs of imbalance

Debugging the carburetor must be done during the manufacture of the device. As a rule, the owners will find out about the need to adjust the fuel supply with their own hands only after serious enough breakdowns, in the process of correcting which, the module was removed and, for example, cleaned.

Signs of a configuration failure are the following:

  • It starts, but the engine immediately stalls. since the engine can only work when a certain amount of gasoline is supplied, if the fuel is too “lean”, that is, the supply channel is blocked, the engine will stop;
  • Too high fuel consumption, a lot of exhaust gases are the result of incomplete combustion of the mixture. In this case, on the contrary, there is too much fuel and the mixture is too dense.

Principle of operation

A carburetor is a power system module in which liquid fuel and air are mixed before being fed into the engine cylinders. Mixing and flow are adjusted accordingly depending on the tool and its mode of operation.

The carburetor device for lawn mowers is the same for almost all cases. It belongs to the category of float devices. The latter provide stable parameters of ready mixes.

The principle of the module is as follows.

  • Air enters the body of the air damper tube. The latter increases or decreases the air flow depending on its position.
  • In the area where the hole for the gasoline supply is formed, the tube has a narrowing. a diffuser. Here the flow rate increases.
  • Fuel from the float chamber is fed through the nozzle into the tube. The float level determines the amount of fuel supplied. Since the pressure in the chamber is normal, and in the tube it is low due to the greater rarefaction of the air, gasoline is sucked in through the nozzle.
  • The accelerated air flow picks up fuel and atomizes it, forming an air-fuel mixture of the desired density.
  • The mixture is sucked into the cylinder through the pipeline.
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The more open the air damper in the tube, the higher the density of the air flow, which means more fuel enters the cylinder. Adjusting the carburetor of lawn mowers is reduced to setting such a ratio of valves at which the density of the fuel mixture becomes optimal.

DIY lawn mowers carburetor adjustment

Module adjustment does not apply to repair and replacement of spare parts is NOT required. In this case, the Lawn Mowers Carburetor Repair Kits are NOT needed.

Three screws are provided for debugging:

  • L. is regulated first, since it is responsible for supplying fuel at low speeds;
  • H. he is responsible for the supply of gasoline at high speeds, as well as for fuel consumption and temperature;
  • T. it is used to debug idle.

There are options, as a rule, this is the carburetor of a Chinese lawn mower, when only one screw remains on the body for debugging. for adjusting the idle speed. This does not mean that the module is configured automatically. it means that it will be difficult to carry out even such a type of repair as debugging. In the photo. adjusting the carburetor of a Chinese lawn mower.

  • The module is configured only when the engine is warmed up: for this, the device is pre-switched on for 10 minutes. If the mowing head rotates while idling, then the debugging is started immediately: turn the screw T counterclockwise until the rotation does NOT stop.
  • Adjustment begins with screw L. The screw turns to the right and left until it finds such a position in which the idle speed does not become maximum.
  • Then the screw is turned 1/4 turn counterclockwise. This will be his working position.
  • Idling must be adjusted by turning counterclockwise to increase the numbers of revolutions and clockwise to decrease. Its debugging consists in achieving such a mode in which a sufficient number of revolutions are made at the beginning of the rotation of the mowing head. In this case, the engine must work stably at different positions.
  • The position of screw L is determined last. at maximum speed, the trimmer should NOT work for more than 10 seconds. The throttle opens, the screw turns clockwise, very slowly, until a decrease in the number of revolutions is audible.
  • Then, also slowly, the screw rotates counterclockwise until the motor starts to malfunction. Then the screw is turned back clockwise until the engine again does NOT start normally.

If there is a tanometer, and if the recommended rpm values ​​are indicated in the product passport, the correction can be carried out more accurate, focusing not on hearing, but on the readings of the device.

Carburetor adjustment of lawn mowers by ear.

8 comments per post “Adjusting and repairing the carburetor lawn mowers”

    Dmitry Pavlovich 07/04/2016

Please clarify. In the adjustment section, item 5, screw L. error? Should you read screw A? Thank you.

Prompt start position of screws H L LA

SHOW THE INITIAL POSITION

Prompt start position of screws H L LA

Thank you very much for the accelerator and did not know, but the defect is very important and creates a huge problem in which almost everyone is silent. BRAVO.

Maybe all the same tachometer is a rpm meter, and not a tonometer blood pressure meter

And I have L, H, LA, it’s LA instead of T?

On some kind of tightness, so you need to be able to chew snot.

Do-it-yourself lawn mowers carburetor adjustment

A lawn mower carburetor is a unit in the power system. In it, like any carburetors, there is a process of mixing air and fuel (gasoline) for further supply to the engine cylinders.

The main problems and malfunctions of the carburetor.

Mesh filter. There are often only two problems with this element:

  • Blockage.
  • Breaking.

In order to find out the cause of the breakdown, the fuel filter cap is unscrewed to remove the mesh filter. If there is simply accumulated dirt on it, then flushing in gasoline or blowing will help.

If there is visible damage to the mesh filter, it is imperative to put a new one. There may also be damage to the fuel supply pipe (during repair, they practice checking this element).

Blowing out carburetor parts with compressed air blockages is an acceptable and convenient repair practice.

Lawn mowers carburetor device

The basis of the carburetor for lawn mowers is an aluminum body. It contains a diffuser (hole with internal contours). Air is blown through this hole. Here is the cross-section (orifice) of the diffuser depends on the oxygen (air) flow rate.

The diffuser is equipped with fuel channels. Fuel is drawn in from them using the air flow.

Outside the carburetor is installed:

  • Fuel pump;
  • Jet system;
  • Air-fuel mixture control system;

The principle of operation of the carburetor lawn mowers

The throttle valve determines the amount of air to be supplied, and the engine power directly depends on this.

Fuel is sucked into the carburetor system by a pump (its membrane). Then it goes through the fitting into the carburetor. The fluid then flows through the pump inlet and outlet valves. Filtered by the grid. The needle valve moves into the diaphragm chamber.

Phased operation of the device:

  • Air supply to a tube with an air baffle (damper). The baffle regulates the intensity of the air flow.
  • The fuel supply system is necessarily narrowed by a diffuser to increase the flow rate.
  • Gasoline through the float chamber and the nozzle tube with a constriction. A float chamber adjusts the temporary volume of gasoline. In the float chamber, the pressure level is neutral, and in the tube with a constriction it is already low. Due to the pressure drop, the fuel penetrates through the jet.
  • The acceleration of the air flow facilitates the transfer of fuel (gasoline) and its atomization. As a result, an air-fuel mixture of the required proportion or density is formed.
  • The air / fuel mixture enters the engine cylinder through the fuel pipe.

Simply put, adjusting the carburetor for lawn mowers is the creation of an optimal fuel mixture due to the correct supply of air.

How to adjust the carburetor on lawn mowers

Before adjustment, you must thoroughly clean the filters according to the maintenance in the instructions.

Further adjustment of the carburetor of the lawn mowers with their own hands is carried out with adjusting screws. There are three of them:

  • Right;
  • Left;
  • Lower.

Right (L). adjusting the fuel mixture for low rpm.

You need to find the maximum idle speed. To do this, slowly unscrew the screw (L) to the right and left.

To adjust, turn the screw a quarter turn counterclockwise.

Lower (T). responsible for adjusting the engine at idle.

  • Clockwise. increase;
  • Counterclockwise. decrease.

For the correct adjustment of the idle speed, it is characteristic:

  • Stable operation of a cold engine;
  • NOT overspeed of a hot engine;
  • Large headroom for the trimmer head;
  • Stable engine operation when changing position (sharp lifting or lowering of the knife).

Left (H). mixture adjustment at high rpm. (The screw is adjusted last).

The carburetor setting for lawn mowers with the last screw is done as follows:

  • Open the throttle to full, while at the same time give full throttle. Turn the screw clockwise until the revolutions fall (in this case, orientate by ear).
  • Return the screw as slowly as possible counterclockwise until the engine runs unevenly.
  • Then they will return quite a bit, barely Hearing stable, even work.
  • For a more visual use of skills, it is more convenient to consider the work of an experienced user:

Interestingly, from the point of view of the author. The setting (its correctness) is determined by the color of the plug, and not only by the speed and stability of the engine.

Correct adjustment of the carburetor with your own hands in this case. combustion of the fuel mixture without residue, the color of the candle should be light brown.

The main problems and malfunctions of the carburetor.

Mesh filter. There are often only two problems with this element:

  • Blockage.
  • Breaking.

In order to find out the cause of the breakdown, the fuel filter cap is unscrewed to remove the mesh filter. If there is simply accumulated dirt on it, then flushing in gasoline or blowing will help.

READ  How to Sharpen a Knife From a Viking Lawn Mower

If there is visible damage to the mesh filter, it is imperative to put a new one. There may also be damage to the fuel supply pipe (during repair, they practice checking this element).

Blowing out carburetor parts with compressed air blockages is an acceptable and convenient repair practice.

The principle of operation of the carburetor lawn mowers

The throttle valve determines the amount of air to be supplied, and the engine power directly depends on this.

Fuel is sucked into the carburetor system by a pump (its membrane). Then it goes through the fitting into the carburetor. The fluid then flows through the pump inlet and outlet valves. Filtered by the grid. The needle valve moves into the diaphragm chamber.

Phased operation of the device:

  • Air supply to a tube with an air baffle (damper). The baffle regulates the intensity of the air flow.
  • The fuel supply system is necessarily narrowed by a diffuser to increase the flow rate.
  • Gasoline through the float chamber and the nozzle tube with a constriction. A float chamber adjusts the temporary volume of gasoline. In the float chamber, the pressure level is neutral, and in the tube with a constriction it is already low. Due to the pressure drop, the fuel penetrates through the jet.
  • The acceleration of the air flow facilitates the transfer of fuel (gasoline) and its atomization. As a result, an air-fuel mixture of the required proportion or density is formed.
  • The air / fuel mixture enters the engine cylinder through the fuel pipe.

Simply put, adjusting the carburetor for lawn mowers is the creation of an optimal fuel mixture due to the correct supply of air.

Do-it-yourself lawn mowers carburetor adjustment

A lawn mower carburetor is a unit in the power system. In it, like any carburetors, there is a process of mixing air and fuel (gasoline) for further supply to the engine cylinders.

Lawn mowers carburetor device

The basis of the carburetor for lawn mowers is an aluminum body. It contains a diffuser (hole with internal contours). Air is blown through this hole. Here is the cross-section (orifice) of the diffuser depends on the oxygen (air) flow rate.

The diffuser is equipped with fuel channels. Fuel is drawn in from them using the air flow.

Outside the carburetor is installed:

  • Fuel pump;
  • Jet system;
  • Air-fuel mixture control system;

How to adjust the carburetor on lawn mowers

Before adjustment, you must thoroughly clean the filters according to the maintenance in the instructions.

Further adjustment of the carburetor of the lawn mowers with their own hands is carried out with adjusting screws. There are three of them:

  • Right;
  • Left;
  • Lower.

Right (L). adjusting the fuel mixture for low rpm.

You need to find the maximum idle speed. To do this, slowly unscrew the screw (L) to the right and left.

To adjust, turn the screw a quarter turn counterclockwise.

Lower (T). responsible for adjusting the engine at idle.

  • Clockwise. increase;
  • Counterclockwise. decrease.

For the correct adjustment of the idle speed, it is characteristic:

  • Stable operation of a cold engine;
  • NOT overspeed of a hot engine;
  • Large headroom for the trimmer head;
  • Stable engine operation when changing position (sharp lifting or lowering of the knife).

Left (H). mixture adjustment at high rpm. (The screw is adjusted last).

The carburetor setting for lawn mowers with the last screw is done as follows:

  • Open the throttle to full, while at the same time give full throttle. Turn the screw clockwise until the revolutions fall (in this case, orientate by ear).
  • Return the screw as slowly as possible counterclockwise until the engine runs unevenly.
  • Then they will return quite a bit, barely Hearing stable, even work.
  • For a more visual use of skills, it is more convenient to consider the work of an experienced user:

Interestingly, from the point of view of the author. The setting (its correctness) is determined by the color of the plug, and not only by the speed and stability of the engine.

Correct adjustment of the carburetor with your own hands in this case. combustion of the fuel mixture without residue, the color of the candle should be light brown.

Lawn mowers carburetor device

The basis of the carburetor for lawn mowers is an aluminum body. It contains a diffuser (hole with internal contours). Air is blown through this hole. Here is the cross-section (orifice) of the diffuser depends on the oxygen (air) flow rate.

The diffuser is equipped with fuel channels. Fuel is drawn in from them using the air flow.

Outside the carburetor is installed:

  • Fuel pump;
  • Jet system;
  • Air-fuel mixture control system;

The principle of operation of the carburetor lawn mowers

The throttle valve determines the amount of air to be supplied, and the engine power directly depends on this.

Fuel is sucked into the carburetor system by a pump (its membrane). Then it goes through the fitting into the carburetor. The fluid then flows through the pump inlet and outlet valves. Filtered by the grid. The needle valve moves into the diaphragm chamber.

Phased operation of the device:

  • Air supply to a tube with an air baffle (damper). The baffle regulates the intensity of the air flow.
  • The fuel supply system is necessarily narrowed by a diffuser to increase the flow rate.
  • Gasoline through the float chamber and the nozzle tube with a constriction. A float chamber adjusts the temporary volume of gasoline. In the float chamber, the pressure level is neutral, and in the tube with a constriction it is already low. Due to the pressure drop, the fuel penetrates through the jet.
  • The acceleration of the air flow facilitates the transfer of fuel (gasoline) and its atomization. As a result, an air-fuel mixture of the required proportion or density is formed.
  • The air / fuel mixture enters the engine cylinder through the fuel pipe.

Simply put, adjusting the carburetor for lawn mowers is the creation of an optimal fuel mixture due to the correct supply of air.

The main problems and malfunctions of the carburetor.

Mesh filter. There are often only two problems with this element:

  • Blockage.
  • Breaking.

In order to find out the cause of the breakdown, the fuel filter cap is unscrewed to remove the mesh filter. If there is simply accumulated dirt on it, then flushing in gasoline or blowing will help.

If there is visible damage to the mesh filter, it is imperative to put a new one. There may also be damage to the fuel supply pipe (during repair, they practice checking this element).

Blowing out carburetor parts with compressed air blockages is an acceptable and convenient repair practice.

Do-it-yourself lawn mowers carburetor adjustment

A lawn mower carburetor is a unit in the power system. In it, like any carburetors, there is a process of mixing air and fuel (gasoline) for further supply to the engine cylinders.

How to adjust the carburetor on lawn mowers

Before adjustment, you must thoroughly clean the filters according to the maintenance in the instructions.

Further adjustment of the carburetor of the lawn mowers with their own hands is carried out with adjusting screws. There are three of them:

  • Right;
  • Left;
  • Lower.

Right (L). adjusting the fuel mixture for low rpm.

You need to find the maximum idle speed. To do this, slowly unscrew the screw (L) to the right and left.

To adjust, turn the screw a quarter turn counterclockwise.

Lower (T). responsible for adjusting the engine at idle.

  • Clockwise. increase;
  • Counterclockwise. decrease.

For the correct adjustment of the idle speed, it is characteristic:

  • Stable operation of a cold engine;
  • NOT overspeed of a hot engine;
  • Large headroom for the trimmer head;
  • Stable engine operation when changing position (sharp lifting or lowering of the knife).

Left (H). mixture adjustment at high rpm. (The screw is adjusted last).

The carburetor setting for lawn mowers with the last screw is done as follows:

  • Open the throttle to full, while at the same time give full throttle. Turn the screw clockwise until the revolutions fall (in this case, orientate by ear).
  • Return the screw as slowly as possible counterclockwise until the engine runs unevenly.
  • Then they will return quite a bit, barely Hearing stable, even work.
  • For a more visual use of skills, it is more convenient to consider the work of an experienced user:

Interestingly, from the point of view of the author. The setting (its correctness) is determined by the color of the plug, and not only by the speed and stability of the engine.

Correct adjustment of the carburetor with your own hands in this case. combustion of the fuel mixture without residue, the color of the candle should be light brown.