Adjusting The Carburetor Trimmer With Your Own Hands

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 the operator. The filled fuel mixture must be enriched with air. a 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 standard carburetor. Its design 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 housing that 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. A 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.

Adjusting The Carburetor Trimmer With Your Own Hands

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 device of the carburetor of lawn mowers 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 that connects the internal cavity of the engine crankcase with the impulse chamber of the pump. The piston located in the cylinder of the engine creates a reciprocating motion, 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 passes through the integrated inlet and outlet 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 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.

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;
  • Prolonged simple trimmer;
  • Intensive growth of loads on the power unit of lawn mowers;
  • Arbitrary unscrewing of the built-in adjusting screws of the carburetor. this causes 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;
  • Engine start and its arbitrary shutdown or slow speed set;
  • 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 serious damage to the trimmer, up to the complete failure of its factory engine.

DIY lawn mowers carburetor adjustment

Periodic adjustment of the trimmer carburetor must be performed on a serviced and fully serviceable 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 reduce the speed generated by the motor. To do this, turn the lower adjuster, often marked with the letter “T”, to the left, until the installed cutter comes to a complete stop.

Further configuration of the fuel assembly is as follows:

  • The “L” regulator, located on the right, is responsible for enriching the fuel mixture with air when the engine is running at low speeds. 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” one by one to the right or left. Once the maximum speed is reached, the screw will need to be turned 1/2 turn to the left;
  • The “T” or “LA” screw 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 regulator “H”, provided on the left, is responsible for enriching the fuel mixture with air when the internal combustion engine trimmer is running at high rpm. This screw is also needed to adjust the engine power and the amount of fuel consumed. Its position is adjusted by turning the screw to the right or left side until the maximum permissible engine speed is reached. After that, the screw “H” will need to be turned 1/2 turn to the left.

Performing these steps one by one will allow you to correctly configure the fuel trimmer assembly, without the risk of exceeding the permissible load on its main working mechanisms.

Trimmer carburetor

The trimmer carburetor is one of the most important components of the unit, which is responsible for the fuel mixture. Incorrect handling of the equipment can damage the element, which makes it impossible to operate the lawn mower without repair. To repair a garden tool, you need to know about its structure, the principle of functioning and the rules of adjustment.

READ  How to Fix a Knife on a Stihl Trimmer

Design features and the principle of operation of the carburetor lawn mowers

Structurally, carburetors practically do not differ from well-known brands and Chinese manufacturers.

The lawn mowers carburetor device consists of the following elements:

  • Booster pump;
  • Tuning systems with atmospheric membrane;
  • A primer that makes it easier to start the motor;
  • Cold running systems;
  • Elastic two-valve plate;
  • Dosing system with rotating rotor;
  • Throttle.

The model functions as follows:

  • From the air damper, the air passes into a tube, which increases or decreases its flow;
  • In the area with a hole for the fuel mixture, the narrowed zone is a diffuser. In this zone, the air moves faster;
  • The fuel mixture from the float chamber enters the pipe through the nozzle. The amount of fuel is determined by the float;
  • The increased air flow picks up the fuel and disperses it. An air-fuel mixture with sufficient density is created;
  • Sucks the mixture with a cylinder through the pipeline.

The concentration of the air flow depends on how slightly the aerofoil is opened, respectively, more fuel is supplied to the cylinder. Adjusting the carburetor of lawn mowers consists in setting the correct ratio of flaps to achieve the optimal consistency of the fuel mixture.

When carburetor adjustment is required?

The operator needs to correct the work of the working unit in certain cases:

  • The new engine was run in using 4-5 liters of fuel;
  • Changed the composition of the fuel. the brand of engine oil and gasoline;
  • The weather conditions have changed (in winter, summer);
  • The level of rarefaction has changed;
  • The load on the power plant has increased;
  • After prolonged storage of the unit;
  • Formation of persistent carbon deposits on the spark plug;
  • The engine immediately stalls after starting or does not develop the required speed;
  • When vibrating, the adjustment screws are loosened;
  • The amount of fuel consumed has increased;
  • Gasoline is not pumped into the cylinder;
  • A lot of exhaust comes out.

How to adjust the carburetor do-it-yourself lawn mowers?

Before setting up the carburetor unit, a certain algorithm of actions is performed:

  • The motor is washed;
  • The spark plug is replaced or cleaned;
  • The air filter is replaced or cleaned. It can be immersed in warm soapy water, after the filter is completely dried;
  • A cord or knives are installed in the trimmer coil to increase the load on the power plant during tuning. The gasoline engine must be idle for at least ten minutes.

If the cutting attachment continues to rotate at idle speed, it is worth reducing the number of revolutions of the power plant. The work is corrected by the screw T, on some models it is marked LA. The idle speed adjuster is unscrewed counterclockwise until the cutting element stops moving.

Adjustment of the carburetor trimmer depends on three screws:

  • L is responsible for the level of pumping the fuel mixture at low speeds. It is tuned first. You need to achieve maximum speed by unscrewing the screw to the desired point. After that, the regulator turns a quarter turn to the left;
  • T (LA). adjusts idle operation. When the screw is turned to the left, the engine speed decreases, to the right, it increases;
  • H allows you to enrich the fuel at maximum speed. The propeller adjusts high speed, fuel economy and power level of the power plant.

The motor must not run at full speed for more than 10 seconds, as it may break.

Eliminates engine breakdown competent tuning:

  • With the engine running, give full throttle;
  • Screw H is unscrewed clockwise until the unit starts to decrease speed;
  • The regulator H is scrolled to the left until the stable functioning of the motor.

If you follow all the instructions, the carburetor for lawn mowers is considered to be tuned: the engine runs at the required speed, a little quadruples at higher speeds, the cutting elements do not rotate without load.

Signs of imbalance

Debugging the carburetor must be done during the manufacture of the device. As a rule, the owners will learn 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.

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 relatively simple design, such a part of the device as a carburetor needs to be adjusted.

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 feeding 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 supplying gasoline 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 the fuel and atomizes it, forming an air-fuel mixture of the desired density.
  • The mixture is sucked into the cylinder through the pipeline.

The more open the air damper in the tube, the higher the density of the air flow, which means that more fuel enters the cylinder. Setting up the carburetor for lawn mowers is reduced to setting such a ratio of flaps, at which the density of the fuel mixture becomes optimal.

DIY lawn mowers carburetor adjustment

Setting up the module does not apply to repair and replacement of spare parts is not required. In this case, the lawn mowers carburetor repair kit will not be 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.
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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 warm: for this, the device is pre-switched on for 10 minutes. If the mowing head rotates at idle speed, the debugging is started immediately: turn the screw T counterclockwise until the rotation stops.
  • Adjustment begins with screw L. The screw is turned to the right and left until it finds such a position at which 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 number of revolutions and clockwise to decrease it. Its debugging consists in achieving such a mode in which a sufficient number of revolutions are made before the start of 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 begins to malfunction. Then the screw is turned back clockwise until the engine starts working normally again.

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

The carburetor of the lawn mowers was not adjusted by ear.

8 comments on the entry “Adjustment and repair of 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 STARTING 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 that almost everyone is silent about. 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 tightness, so you need to be able to chew snot.

Carburetor Trimmer Adjustment

The initial step in restoring the correct operation of the fuel system is to clean the air filter.

Trimmer carburetor with screws

Experts recommend rinsing it in a solution of water and detergents after every 10-15 hours. Direct adjustment of the carburetor trimmer is done with three adjusting screws:

  • Fuel supply adjustment screw (“L”);
  • High speed adjustment screw (“H”);
  • The screw responsible for the operation of the engine at idle speed (“T” or “AT”).

Adjusting the maximum speed screw for lawn mowers

After restoring the fuel supply at minimum speed and adjusting the idle speed, it is necessary to check the stability of the mechanism at an increased speed.

Tuning at maximum speed

The motor is adjusted at high speeds in order to protect against overheating and to reduce hand fatigue when pressing the accelerator button. If the internal combustion engine is unstable at maximum speed, then the screw “H” must be tightened slowly until smooth and precise operation is ensured.

During operation of the lawn mowers it may be necessary to adjust the fuel screw (“L”) for the optimal set of revolutions.

Carburetor Adjustment Lawn Mowers Highlights

Despite their high productivity, mobility and unpretentious work, modern lawn mowers can hardly be classified as complex devices. Over time, any mechanism is subject to wear and tear, and therefore parts and assemblies require special attention from the owner. One of these trimmer elements is the carburetor, designed to form the fuel mixture and feed it into the combustion chamber. Increased consumption with proper respect for the proportions of gasoline and oil or a drop in engine power indicate the need to adjust the carburetor of the gasoline trimmer.

Fuel supply adjustment at minimum speed

Before starting tuning the carburetor of the gas trimmer, it is required to warm up the engine to operating temperature.

Fuel adjusting screws

To do this, we start the internal combustion engine and let it run for 10-15 minutes at idle. In the first step, with the trimmer running, slowly tighten the screw “L” until the start of intermittent operation or until it stalls. Next, we unscrew the screw орота of a turn and check the speed of a set of maximum revolutions. If the lawn mower reaches high revs easily and quickly, this will be the most economical mode. In most of the models on the market, the fuel screw “L” is turned clockwise, but there are trim tabs where the decrease and increase in the supply of the mixture occurs in the opposite order.

Adjusting the idle trimmer

Location of carburetor adjustment screws

The screw “T” (“AT”) serves as a limiter for the reciprocating movement of the fuel flap and when it is tightened, the engine speed increases, and loosening leads to a decrease in the crankshaft speed. Professionals advise adjusting the idle screw of lawn mowers so that the internal combustion engine runs a little faster at minimum speed, but the head with a fishing line or knife remains stationary. If after the performed manipulations it is difficult to start the trimmer “cold”, then it is enough to tighten the screw “T” a quarter of a turn and try to start the engine again.

Gas trimmer carburetor repair tips

  • Regardless of the manufacturer, there is a factory defect in the carburetor parts of the lawn mowers.

Adjusting screw spring

For example, the tuning technique described above may not give positive results if the number of turns at the spring of the screw for supplying the mixture is too large and, as a consequence, the impossibility of optimally reducing the level of supplied gasoline. To eliminate this, you can shorten the spring yourself a little or, in accordance with the operating manual, purchase a new one.

Many lawnmower owners follow the fuel mixture recommendations listed there when buying oil.

Petrol trimmer oil

So, often the information on mixing gasoline with oil indicated on the bank differs from the instructions in the trimmer passport. As a result, black carbon deposits can quickly build up on the spark plug, leading to a drop in power and increased fuel consumption. Therefore, when preparing the working mixture, you should follow the recommendations specified in the operating manual. In most cases, the proportion for a run-in ICE is 1:25. It is worth noting that many tool owners prefer to prepare fuel “by eye”, which will certainly lead to rapid wear of the piston streamer in the event of a decrease in the oil portion and the formation of carbon deposits on the spark plug with an increased amount of lubricant.

  • Correctly performed above tips for adjusting the trimmer carburetor will help to avoid not only engine overheating, increased fuel consumption, but also significantly increase the service life of other parts and assemblies of the tool. Pay attention to the operation of the lawn mowers in all modes and carry out regulated maintenance and repair of the tool in time.
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    Husqvarna 125R carburetor tuning without tachometer (workaround)

    How to adjust the carburetor, if you need to work, and service with a tachometer is far away.

    Carburetor lawn mowers Stihl, Makita, Husqvarna and others is adjusted with adjusting screws. Sometimes the reason for the malfunction is a violation of fixation. due to vibration or damage to the protective cap. Such a breakdown can be detected by simply trying to turn the screw slightly: if the fixation is not rigid, it is worth checking the setting.

    Self-repair recommendations

    In order to wonder as rarely as possible how to repair an engine, carburetor or gasoline trimmer gearbox with your own hands, do not purchase uncommon models, because. It will be extremely difficult to find details for them, and from official dealers do not always correspond to the possibilities of buyers. If you are a beginner in working with complex technical products, then it is better to contact the service department for help, because K. Self-tuning the carburetor, for example, can further lead to combustion of the entire piston system. In addition, some parts cannot be repaired at all, and the whole unit is subject to replacement; in this case, hand-made repairs will not make sense. Also, do not rush to open the tool case if it is under warranty.

    To help, we can suggest that you contact the services of a trimmer repairman, who can be found on one of the sites, for example, profi.Ru. LINK (do not forget to select your city). At least if the repair of the tool is carried out by a master, you can be sure of the result.

    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 feeding are adjusted appropriately depending on the tool and its mode of operation.

    The device of the carburetor lawn mowers is the same for virtually all cases. It belongs to the category of float devices. The latter provide constant characteristics of the finished consistencies.

    The mechanism 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 own position.
    • In the area where the hole for supplying gasoline is formed, the tube has a narrowing. a diffuser. Here the flow rate increases.
    • Fuel from the float chamber is fed into the tube through the nozzle. The float level determines the amount of fuel supplied. Because 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 through the nozzle.
    • The accelerated air flow picks up the fuel and atomizes it, forming an air-fuel mixture of a suitable density.
    • The mixture is sucked into the cylinder through the pipeline.

    The more strongly the air damper in the tube is opened, the higher the density of the air flow, and, therefore, more fuel enters the cylinder. Setting up the carburetor of lawn mowers is reduced to setting such a ratio of flaps at which the density of the fuel consistency becomes good.

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    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 severe reasons. damage to the piston ring, for example, repairs are reduced to replacing a part.

    And even with a relatively conventional design, such a part of the device as a carburetor needs adjustment.

    We do everything ourselves with our own hands at home

    Funny Pencil. When carburetor adjustment is required?

    The operator needs to correct the work of the working unit in certain cases:

    • The new engine was run in using 4-5 liters of fuel;
    • Changed the composition of the fuel. the brand of engine oil and gasoline;
    • The weather conditions have changed (in winter, summer);
    • The level of rarefaction has changed;
    • The load on the power plant has increased;
    • After prolonged storage of the unit;
    • Formation of persistent carbon deposits on the spark plug;
    • The engine immediately stalls after starting or does not develop the required speed;
    • When vibrating, the adjustment screws are loosened;
    • The amount of fuel consumed has increased;
    • Gasoline is not pumped into the cylinder;
    • A lot of exhaust comes out.

    How to adjust the carburetor do-it-yourself lawn mowers?

    Before setting up the carburetor unit, a certain algorithm of actions is performed:

    • The motor is washed;
    • The spark plug is replaced or cleaned;
    • The air filter is replaced or cleaned. It can be immersed in warm soapy water, after the filter is completely dried;
    • A cord or knives are installed in the trimmer coil to increase the load on the power plant during tuning. The gasoline engine must be idle for at least ten minutes.

    If the cutting attachment continues to rotate at idle speed, it is worth reducing the number of revolutions of the power plant. The work is corrected by the screw T, on some models it is marked LA. The idle speed adjuster is unscrewed counterclockwise until the cutting element stops moving.

    Adjustment of the carburetor trimmer depends on three screws:

    • L is responsible for the level of pumping the fuel mixture at low speeds. It is tuned first. You need to achieve maximum speed by unscrewing the screw to the desired point. After that, the regulator turns a quarter turn to the left;
    • T (LA). adjusts idle operation. When the screw is turned to the left, the engine speed decreases, to the right, it increases;
    • H allows you to enrich the fuel at maximum speed. The propeller adjusts high speed, fuel economy and power level of the power plant.

    The motor must not run at full speed for more than 10 seconds, as it may break.

    Eliminates engine breakdown competent tuning:

    • With the engine running, give full throttle;
    • Screw H is unscrewed clockwise until the unit starts to decrease speed;
    • The regulator H is scrolled to the left until the stable functioning of the motor.

    If you follow all the instructions, the carburetor for lawn mowers is considered to be tuned: the engine runs at the required speed, a little quadruples at higher speeds, the cutting elements do not rotate without load.