How to adjust the carburetor on a lawn mower and trimmer

A petrol mower or trimmer with an internal combustion engine requires not only constant refueling of the fuel mixture of gasoline and oil, but also periodic adjustment of the supply of this fuel. The carburetor is responsible for supplying fuel to the cylinder of the lawn mower, and the efficiency and performance of the tool depends on its proper operation. If during operation a faulty (abnormal) engine operation is detected, the first step is to adjust the carburetor of the lawn mower. Before adjusting the carburetor of a gasoline trimmer, let's first understand its design.

How to find out if your lawn mower's carburetor needs adjustment

Many craftsmen use lawn mowers for a long time, and do not think about the need to adjust the carburetor of the tool. When is it necessary to adjust the carburetor on a lawn mower or brush cutter? If you are asking this question, then you are probably seeing changes in the operation of the engine that are not for the better. In order not to guess and not to miss the moment when it is necessary to adjust the carburetor, you should adhere to the following recommendations on the need for adjustment measures:

After the engine has been run-in. Typically, running-in lasts for the duration of burning 4-5 liters of fuel.
When a fuel mixture of a different composition is poured into the tank, that is, the type of oil (even its color) and the brand of gasoline change
When weather conditions change, however, this is more relevant for chainsaws, gas generators and motor pumps, which are used not only in summer, but also in winter.
If the lawn mower has not been used for a long time. The reason for the need for adjustment may be the winter break.
When fuel consumption increases
If black carbon deposits are detected on the spark plug electrodes
If there is no gasoline entering the cylinder or the engine starts poorly
If a large amount of exhaust gas is detected
Unstable engine operation, as well as difficult starting and “sluggish” speed gain

As you can see, there are enough reasons to adjust the carburetor of a lawn mower. Typically, craftsmen who have been working with a tool for a long time can hear changes in the operation of the motor, which indicates the need for an adjustment process. Even if you are not sure about the need to carry out adjustment work, then performing it out of turn will definitely not be superfluous.

When is it necessary to adjust the carburetor of a household trimmer?

You need to adjust the trimmer's built-in carburetor when:

Do-it-yourself carburetor adjustment for VAZ 2107

running-in of the new engine, during which 4 to 5 liters of the fuel mixture were used;
sudden changes in weather;
changes in air rarefaction - for example, when a brush cutter is often used in mountainous areas;
prolonged downtime of the trimmer;
intensive increase in loads on the power unit of the lawn mower;
arbitrary unscrewing of the built-in carburetor adjustment screws - this causes increased vibration of the internal combustion engine;
changes in the quality of fuel mixture components;
overfilling the carburetor with fuel, resulting in increased fuel consumption;
the regular appearance of a thick layer of resinous deposits and carbon deposits on the surface of the electrodes of the standard trimmer spark plug;
starting the engine and turning it off randomly or slowly picking up speed;
lack of fuel flow into the cylinder of the power unit;
increasing the volume of exhaust gases emitted.

Failure to timely adjust the carburetor threatens serious damage to the trimmer, up to and including complete failure of its factory engine.

Starting the engine

The engine is started at a distance of 3 m or more from the place where the device is refueled. This work cannot be carried out indoors. Before you need to take a stable, reliable position. At the same time, the motorcycle device is held very tightly. The cutting tool should not come into contact with the ground or objects, because it may spin when started.

The unit is serviced by only one person; however, there should be no third parties in the area with a radius of up to 15 m. Otherwise, you may be injured by thrown objects. Starting the motor of the Shtil FS 55 lawn mower, the properties of which are presented in the article, should not be done by hand. After releasing the gas lever, the cutting tool will move for some time by inertia. Flammable materials should be kept away from the hot flow of gases and the surface of the hot muffler, because this may cause a fire.

Principle of operation

The procedure for pumping and filtering fuel into the lawn mower engine is as follows.

The throttle valve controls the amount of air supplied to the diffuser. The more air supplied, the more oxygen the gasoline needs to burn, and the more power is released in the form of heat. The heat energy is further converted into mechanical energy.
The diaphragm pump pumps the required amount of gasoline.
Next, gasoline passes through the engine fitting.
Fuel passes through the intake and exhaust valves.
Fuel is filtered using a mesh filter.
Through the needle valve, it enters the chamber with the membrane.

The stages of operation of the carburetor are as follows.

The air enters the pipe with an air damper. The damper sets the desired air flow intensity.
In the gasoline injection unit, the diffuser is narrowed - this is necessary to give greater air flow speed.
The fuel passes through the compartment with the float and bypasses the nozzle and enters this narrowing of the tube. The float compartment meters the supply of gasoline. In this compartment the pressure is in a state of equilibrium. In a narrowed tube it decreases. Due to the difference between both pressure values, gasoline passes through the nozzle.
The accelerated flow atomizes gasoline, converting it into aerosol vapor. The resulting gasoline-air mixture is ready for ignition in the combustion chamber.
After passing through the fuel pipeline, this mixture ends up in the carburetor cylinder.

Conclusion: To set the required power, you will first adjust the rate of fuel combustion using the choke. If the gap is too small and the oxygen in such a mixture is less than 10%, the fuel does not burn, therefore, the engine will not start or will stall immediately.

If you buy a Chinese trimmer, it is worth considering that it differs little from European ones - the same 2- or 4-stroke engine and drive.

problems with cutting blade rotation

All trimmers have a rod with a cutting blade at the end; they come in two types: straight with a gearbox at the end and curved with direct transmission to the bushing. If you are the owner of a straight rod, look at 3 components: clutch, shaft, gearbox. And if you have a curved rod: look at the bushing and rod accordingly

Pay attention to the integrity of the connections, check the connecting splines on the shaft, gearbox or sleeve. You can check the drive if the engine is running properly.

Our practice shows that many people confuse motor and drive problems. If the motor is clogged or faulty, it may appear that there is no transmission to the belt.

Trimmer clutch malfunction

All gasoline trimmers are equipped with a centrifugal clutch, the meaning of which is that the pads, when adding speed, begin to move apart and catch the cup. The easiest way to check the clutch is to unscrew the rod from the motor, usually 4 bolts. If the pads are worn out and the clutch needs to be replaced, a metallic grinding noise can be heard. If your trimmer has a clutch and the line is constantly rotating, then the spring is stretched.

Drive shaft and rod malfunctions

The main thing to look at is: the splines on the shaft, the connection between the gearbox and the clutch cup. It is also very common for users to not properly insert the shafts into the joint on trimmers with collapsible shafts. Be sure to check the integrity of the shaft. If there is vibration when mowing, it means the plastic bushings are broken. Vibration is very harmful to the vascular system. In order to avoid melting of the bushings, they must be lubricated and the mower allowed to rest.

How to adjust the carburetor on a lawn mower

Before adjustment, the filters must be thoroughly cleaned according to the maintenance instructions.

Further adjustment of the lawn mower carburetor is done with your own hands using adjusting screws. There are three in total:

right;
left;
lower.

Right (L) – adjusting the fuel mixture for low speeds.

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

To adjust, turn the screw a quarter turn counterclockwise.

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

clockwise – increase;
counterclockwise – decrease.

For correct adjustment of idle speed it is typical:

stable operation of a cold engine;
not over-revving a hot engine;
there is a large reserve of revolutions for the trimmer head;
stable operation of the engine when changing position (sharp raising or lowering of the knife).

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

Setting up the carburetor of a lawn mower with the last screw is done as follows:

Open the throttle to full, while releasing full throttle. Turn the screw clockwise until the speed drops (in this case, use your ear).
Turn the screw as slowly as possible counterclockwise until the engine runs rough.
Then turn back just a little, barely hearing stable, smooth operation.
For a more visual application of skills, it is more convenient to consider the work of an experienced user:

It is interesting that from the point of view of the author of the video, the setting (its correctness) is determined by the color of the spark plug, and not just by the engine speed and stability.

Correctly adjusting the carburetor with your own hands in this case means combustion of the fuel mixture without residue; the color of the spark plug should be light brown.

The principle of operation of a lawn mower carburetor

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

Correct carburetor

determined by the operation of the motor and the color of the spark plug. Adjusted

Self-adjustment of the carburetor

on a Chinese trimmer, quickly and easily adjust
the carburetor
to

Fuel is sucked into the carburetor system by a pump (its membrane). Then it passes through the fitting in the carburetor. The liquid then moves through the inlet and outlet valves of the pump. Filtered with a mesh. It moves through the needle valve into the membrane chamber.

Step-by-step operation of the device:

Air supply into a tube with an air baffle (damper). The partition regulates the intensity of the air flow.
The fuel supply system is certainly narrowed by the mixer to speed up the flow.
Gasoline through the float chamber and the nozzle tube with a narrowing. A chamber with a float regulates the temporary volume of gasoline. In the float chamber the pressure level is neutral, but in the tube with a narrowing it is already small. Due to the pressure difference, fuel leaks through the nozzle.
Acceleration of the air flow promotes the transfer of fuel (gasoline) and its atomization. Ultimately, an air-fuel mixture of the required proportion or density appears.
The air-fuel mixture seeps into the engine cylinder through the fuel pipe.

The level of air density in the system depends on the area of the open air damper. The wider the damper is open, the greater the fuel consumption and power.

Simply put, adjusting the carburetor on a lawn mower is creating a good fuel consistency due to the correct air supply.

What is the problem with trimmer malfunction?

Champion lawn mower carburetor, how to adjust? This is a float-type trimmer - a common option designed to mix air and fuel in the prescribed proportions. The main problems that arise during engine operation are approximately similar to problems that occur with the carburetor in a car:

Carburetor repair

Important! The carburetor has to be adjusted under various circumstances: a change in temperature, fuel octane number or oil type, after winter or the end of the break-in period, load or spontaneous turning of the screws due to strong vibration of the body. Some owners prefer to tune the module before each use to ensure it is working correctly.

How to adjust the carburetor on a lawn mower

The upcoming adjustment of the lawn mower carburetor is done with your own hands using adjusting screws. There are three in total:

Right (L) – adjusting the fuel consistency for low speeds.

It is necessary to find the highest idle speed. To do this, slowly unscrew the screw (L) to the right and to the left.

To adjust, turn the screw a quarter turn, always counterclockwise.

Bottom (T) – is responsible for adjusting the engine at idle.

clockwise – increase;
counterclockwise – decrease.

For correct adjustment of idle speed specifically:

stable operation of a cold engine;
not over-revving a hot engine;
there is a large reserve of revolutions for the trimmer head;
stable operation of the engine when changing position (sharp raising or lowering of the knife).

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

The overall adjustment of maximum speed, engine power, temperature and gasoline consumption depends on the left screw (H).

Setting up the carburetor of a lawn mower with the last screw is done as follows:

Open the throttle to full, while releasing full throttle. Turn the screw clockwise until the speed drops (in this case, use your ear).
Turn the screw as slowly as possible counterclockwise until the engine runs rough.
Then turn back just a little, barely hearing stable, smooth operation.
For a more visual application of skills, it is more convenient to consider the work of an experienced user:

It is interesting that from the point of view of the author of the video, the setting (its correctness) is determined by the color of the spark plug, and not just by the engine speed and stability.

with your own hands

Post Views: 10

Signs of imbalance

The carburetor must be debugged during the manufacture of the device. As a rule, owners learn about the need to adjust the fuel supply with their own hands only after quite serious breakdowns, during the process of correcting which the module was removed and, for example, cleaned.

Signs of a settings failure include the following:

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 much fuel consumption, a lot of exhaust gases - the result of incomplete combustion of the mixture. In this case, on the contrary, there is too much fuel and the mixture turns out to be excessively dense.

The carburetor of STIHL, Makita, Husqvarna and other lawnmowers is adjusted using adjusting screws. Sometimes the cause of 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 slightly turn the screw: if the fixation is not tight, it is worth checking the setting.

How does a lawn mower carburetor work or its operating principle?

Adjusting the carburetor of a Chinese lawn mower is completely identical to the adjustment of lawn mowers from European, Russian and other manufacturers. To cope with the task of adjusting the carburetor on lawn mowers and gas trimmers, you need to understand the principle of their operation. How a carburetor works on a lawn mower is described step by step and in an accessible manner below.

The operation of the lawn mower carburetor begins with the supply of fuel through the channel, as shown in the diagram
Fuel is sucked into the carburetor using a pulse channel connected to the engine crankcase. Due to rarefaction of air, the flexible membrane at number 4 in the diagram above moves
Fuel is supplied through valves 3 and 5. Valve 3 is an inlet valve, due to which fuel is supplied to the sub-membrane space, and valve 5 is an outlet valve
Next, the fuel moves along the channel and, passing through a fine filter, reaches the needle valve 14
The needle valve is connected via a lever to the control diaphragm 18
The needle valve is activated by pressure on the membrane. When it is necessary to pump up fuel to start the engine, it is necessary to operate the soft cover of the hand pump. When exposed, the needle opens and the chamber is filled with the fuel mixture
When the engine starts (cold), the needle opens due to vacuum when the air damper is closed. This vacuum acts through the idle and high speed jets on the membrane 18
The membrane acts through a lever on the needle valve, thereby filling the chamber
After starting the engine, the air damper opens, causing the engine to run lean as fuel mixes with air.
When the chamber is full, the fuel mixture is supplied (sucked in) through the idle and medium speed jets (when the engine is running)
The throttle valve is shifted from its original position by 10-15 degrees
When work is carried out under load, fuel begins to flow into the chamber through the high-speed nozzle, and at the same time the throttle valve rotates at an angle of up to 90 degrees (depending on the force of pressing the gas). In all operating modes, the air damper must be open, through which the fuel is mixed with air, thereby igniting the mixture in the cylinder

Below is a diagram of the operating principle of a lawn mower carburetor. Based on the diagram, you can not only understand the principle of operation, but also identify breakdowns and other malfunctions of the mechanism.

When operating the tool, it is necessary to take into account the presence of another jet. This jet is located between the idle and full power passages. It is necessary in order to avoid severe leaning of the mixture, which occurs when the engine operates at partial load. In such a situation, the occurrence of a bullying couple cannot be ruled out. Through an additional channel (nozzle), fuel is sucked into the chamber, thereby enriching the fuel-air mixture. The diagram below shows an additional jet, which is designated by the number 1.

Having an idea of the design of the diaphragm carburetor of a brush cutter and the principle of operation, it will not be difficult to configure it yourself. To adjust the carburetor of a lawn mower, adjusting screws are used. The diagram above shows two screws for adjustment, however, most modern models of gasoline trimmers are equipped with three screws. The presence of three adjustment screws allows for more precise adjustment, while achieving stable and uninterrupted operation of the internal combustion engine.

This is interesting!
What is the difference between a trimmer and a lawn mower? Many people think that trimmers are low-power electric lawn mowers. However, trimmer is a generic name for gas trimmers, walk-behind trimmers and electric mowers as they are designed for a common purpose.

The design of a gas trimmer carburetor and its purpose

Petrol mowers are equipped with two-stroke internal combustion engines. A carburetor is used to supply the air-fuel mixture to the engine cylinder. In the design of gasoline units, this is a key element, without which the operation of the internal combustion engine is impossible. Moreover, this carburetor differs from a car device not only in size, but also in its operating principle. In particular, this difference lies in the presence of a membrane, which plays the role of a fuel pump. It is due to the presence of a membrane that the devices under consideration in the design of two-stroke internal combustion engines are called membrane ones.

Structurally, the entire mechanism is a small part, inside of which there are channels, valves and membranes. The carburetor body is made of aluminum, and the internal structure is shown in the photo below.

Before you adjust the carburetor of a lawn mower with your own hands, you need to understand all the components of the device in question. The carburetor of a lawn mower and trimmer consists of the following parts:

Diffuser or Venturi nozzle - air is sucked into the system through this nozzle
Air damper - opens and closes the filtered air supply
Maximum speed fuel channel
Fuel channels (nozzles) for idle speed and medium speed
Throttle valve - the opening value is adjusted by pressing the gas
Pulse channel fitting - connects to the internal channel of the engine crankcase
Fuel inlet channel (fitting) (2) - provides fuel supply from the gas tank
Membrane (4) - responsible for sucking fuel from the gas tank
Tank fuel suction valve (3)
Fuel supply valve to the carburetor channel (5)
Filter element (6) or fine fuel filter
Fuel channel (10)
Needle valve needle (14) - responsible for supplying fuel to the control membrane chamber
Chamber - the fuel mixture, which is supplied through the jets and throttle valve into the cylinder
Control membrane (18) - ensures manual fuel suction using a primer
Lever connected to membrane (17)
Idle speed screw(15)
Screw for adjusting the amount of fuel supplied to the diffuser (13)

Having an idea of how the carburetor works inside, you have to understand the principle of its operation. A detailed description of how a carburetor works on a two-stroke internal combustion engine using the example of a chainsaw is described in this material.

The principle of operation of a lawn mower carburetor

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

Step-by-step operation of the device:

Air supply into a tube with an air baffle (damper). The partition regulates the intensity of the air flow.
The fuel supply system is necessarily narrowed with a diffuser to increase the flow rate.
Gasoline through the float chamber and the nozzle tube with a narrowing. A chamber with a float regulates the temporary volume of gasoline. In the float chamber the pressure level is neutral, and in the tube with a narrowing it is already low. Due to the pressure difference, fuel penetrates through the nozzle.
Accelerating air flow promotes 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.

The level of air density in the system depends on the area of the open air damper. The wider the throttle is open, the greater the fuel consumption and power.

Simply put, carburetor adjustment

on a lawn mower – creating an optimal fuel mixture due to the correct air supply.

Basic problems

Malfunctions of the carburetor of a lawn mower or trimmer, despite the relative ease of their elimination, sometimes require a long search by elimination. The main reasons are:

unsatisfactory quality of gasoline purification;
air filter clogged;
accumulation of deposits and carbon deposits in the compartments and passages of the carburetor.

Each of the problems has its own reasons.

Fuel injector malfunction

The most recurring failure is wear and tear of the membrane. As a result, its non-adherence. Fuel passages are not sealed at certain stages of the engine cycle. The reasons here are:

you work for too long on a lawn mower or trimmer without a break;
low-quality fuel was filled;
exhaust gases enter the pulse channel.

A deformed membrane has several bad consequences:

there is not enough gasoline or oxygen in the created combustible mixture;
the engine starts after 10 or more unsuccessful attempts;
the engine knocks, clatters during operation, etc.;
the working piston is deformed.

Strainer clogged

The reasons for a clogged strainer are poor fuel cleaning, damage to the hose and/or injection head.

Failure of the adjustment lever

Wear of the contact edge of the lever is a consequence of incompletely purified fuel, which contains grains of sand or particles of clay, metal, or other inclusions that are insoluble in liquid hydrocarbons. A problem appears with fuel injection; the engine operates intermittently without load.

Inlet needle is damaged

The inlet needle breaks due to the presence of metal and stone particles in gasoline. As a result, the intake needle seat does not fit tightly to it, and the fuel mixture flows. There is too much air in the combustible mixture created by the carburetor, which can cause the engine to “sneeze” during operation. Finally, the needle may become stuck due to low-quality gasoline, or the unit has been idle for a long time.

Clogging of the adjustment space

Deposits may accumulate in the adjustment compartment. The needle does not close the hole completely, and a lot of gasoline enters the fuel chamber - the engine overflows it, possibly flooding the spark plugs. Because of this, the gasoline-air mixture contains an increased amount of gasoline vapor. The efficiency drops noticeably.

The adjustment membrane is damaged

The membrane often becomes deformed (and sometimes breaks) due to the continuous operation of a lawn mower or trimmer for several hours. If you abuse this “impact” mode of operation, damage to the membrane occurs more often. New breakdowns will rain down like from a cornucopia:

the piston breaks;
the number of attempts to unsuccessfully start the engine will increase sharply;
the fuel mixture will contain too little gasoline;
The useful (thermal) power will drop sharply.

Intake control lever sticks

Sticking of the adjustment lever is a consequence of its incorrect installation or accidental bending. The contacting edge will be in the wrong position. This will disrupt the additional injection of gasoline.

The valve is worn out

The throttle and air dampers become unusable due to the entry of dust, metal particles, etc. with the air flow. Damaged dampers look like parts that have been sand blasted. Due to wear on the dampers, the efficiency of the motor decreases and breakdowns are detected. The piston and cylinder wear out.

In some cases, this filter is simply not suitable for your model of lawn mower or trimmer. Ultimately, the motor shaft will suffer - pieces of it will fall into the engine channels, causing the piston to break.

Carburetor cannot be adjusted

The springs on the adjusting screws are to blame for the fact that the adjustment is too rough (it is not possible to set the parameters accurately). The manufacturer of a brush cutter or trimmer may supply excessively thick and stiff springs. You can find others either in workshops where similar equipment is repaired, or purchased from any dealer or official representative of the company that produced the motor for your trimmer or mechanical scythe.

The primer is broken

Primer is a manual mini-pump for forced pumping of fuel into the carburetor. To successfully start the engine, you may need to pump 20 ml of gasoline manually.

The lawn mower engine does not want to start after winter

Often, with the onset of spring, most owners of lawn mowers complain about the inability to start the engine of this lawn-mowing tool. With what it can be connected? In order for the trimmer to start up well in the spring after winter storage, you need to learn how to properly care for it. How to properly store a lawn mower in winter is described in detail at the very end of the material. Now let’s figure out why it’s impossible to start the tool’s motor after winter.

One of the main reasons why a lawn mower won’t start after winter is fuel stagnation in the gas tank. If you do not drain the fuel from the tank and leave the tool for a long time, it will naturally be impossible to start the lawn mower. The properties of the mixture of gasoline and oil decrease, so as a fact we get a malfunction of the tool. Even if there is fuel mixture left in the trimmer from last year, it is recommended to drain it and refill with freshly prepared one. After this, launch the tool.

Another reason could be a faulty air damper. When closing it manually, the valve itself may not work, so you start the lawn mower with the air damper fully open. In this case, the tool will not start when cold, as there is a large air leak. The video below explains why the trimmer does not start when cold.

https://youtube.com/watch?v=KryYvHYDdBI%3F

In addition to these reasons for the impossibility of starting the engine of a lawn mower, there are others that are also important to mention:

Dampness of the spark plug electrodes - before starting the trimmer after winter, you should unscrew the spark plug, inspect it, clean it, dry it and set the gap
Damage to the high voltage wire. During storage of the instrument, the high-voltage wire could crack, become damaged, or be chewed by mice. Make sure the armored wire is intact if the trimmer does not start after winter
Oxidation of wire contacts. This usually happens if the instrument is stored in a room with high humidity.
Check the serviceability of the ignition coil. Over the winter, this part could fail and cause difficulty starting the tool.
Carburetor adjustment - it is recommended to adjust the carburetor after winter. To do this, the tool must start, so if it is impossible to start, it is recommended to pour 20 grams of fuel mixture into the spark plug hole and start the engine
Carry out all the above actions, since during long-term storage the breather hole, filters could become clogged, and corrosion could form on the walls of the exhaust system

https://youtube.com/watch?v=FOeoBsVeiH0%3F

Carry out diagnostics of the tool, and only after that resort to more serious repairs - cleaning the carburetor.

Carburetor design

A petrol mower (motor mower) contains a base - an aluminum body, which houses the remaining parts that work harmoniously as a single whole. The carburetor body has a diffuser - a passage with internal channels through which air is pumped.

Channels branching from the diffuser deliver fuel, with which the injected air is mixed, carrying gasoline vapor with it. Outside the main compartment of the carburetor are located:

jets;
mini fuel pump;
a unit that regulates the mixing of fuel with air.

The latter forms that very explosive mixture that ignites in the combustion chamber of the carburetor.

Adjusting the Husqvarna carburetor

Before adjusting the Husqvarna, do maintenance on the trimmer (wash the trimmer and engine, replace the spark plug, eliminate minor defects).

Be sure to wash the foam air filter element. Wash the element in warm water and soap, then wring out and dry (or replace if it is old or damaged).

Note: If you adjust a Husqvarna carburetor with a dirty air filter, the fuel mixture will become much leaner after cleaning the air filter (which can lead to poor performance or even engine failure). Install a trimmer head with the maximum permissible diameter and standard length of cord (up to the cutting blade in the additional protection) to create a load on the engine when adjusting the high speed screw of the Husqvarna carburetor. Start the trimmer according to the Husqvarna Manual and warm it up for 10 minutes (if the trimmer head rotates at idle speed, then the idle speed screw, i.e.

the bottom one must be turned counterclockwise until the rotation of the trimmer head stops). Carefully turn both needles (right and left) to the middle position between fully unscrewed and fully screwed in (do not turn by the stopper!, this may cause damage to the Husqvarna engine)

There are three adjusting screws for adjusting the Husqvarna carburetor: right, left and bottom.

1) Right screw L - adjusts the enrichment of the low speed mixture (adjusted first): Find the maximum idle speed by slowly turning the right screw to the right and left. Then turn this screw ¼ turn counterclockwise. Note: From the Husqvarna factory the right hand screw was turned out completely (0.5 turn). Now he is looking at 11 o'clock. 2) Lower screw T - adjusting the idle speed of the Husqvarna engine (if necessary): turning the screw clockwise increases the idle speed, counterclockwise decreases it.

The idle speed adjustment is considered correct when:

A cold engine idles steadily.
A hot engine does not idle too high.
Before the trimmer head starts rotating, there is a sufficient reserve of revolutions.
The engine operates stably in any position (for example, when the knife is sharply lowered).

Note: From the factory (Husqvarna), the idle screw was turned from fully tightened to 8 full turns and “2 o’clock” (now it remains so). The recommended idle speed of the Husqvarna lawn mower engine is 2,900 rpm. 3) Left screw H – regulates the enrichment of the mixture at high speeds (adjusted last). It regulates maximum speed, engine power, temperature and fuel consumption.

Note: The Husqvarna engine should not be run at full speed for more than 10 seconds!

Open the throttle fully (full throttle) and slowly turn the left screw clockwise until the Husqvarna engine speed is reduced (audibly).
Then turn the left screw very slowly counterclockwise until the engine starts to run rough.
After this, turn the screw slowly back a small distance clockwise until the Husqvarna engine starts to run smoothly.

This completes the Husqvarna adjustment.

Note: The recommended maximum speed of the Husqvarna engine is 11,500 rpm. The maximum engine power output of the Husqvarna 333R trimmer is 1.6 kW (2.1 hp) at 8,400 rpm.

Note: On a new Husqvarna trimmer from the manufacturer (Husqvarna), the left screw was completely unscrewed (0.5 turn) and blocked (filled) with hard plastic, which I drilled out after the warranty expired. Now the left propeller (like the right) is pointing at approximately 11 o'clock.

Checking the correct settings of the Husqvarna carburetor

The engine revs quickly, smoothly and confidently, and revs a little at maximum speed; the T-35 trim head should not rotate at idle.

Fikrlar • 107

The trimmer starts and goes into overdrive, the idle is not adjustable, the caburator is like in the video. What to do?

Sergei Radionov, perhaps the reason is different. is spreading, which means foreign air is getting in

In general, my fastening broke off, that is, the eye that holds the cable, I need to replace this valve, it’s difficult to remove it, put it on, or I need to make some adjustments later

LIKE! Is it difficult to change the fastening of the throttle cable with the ECHO GT22 valve in a trimmer yourself?

vatunov is not difficult, but the cable is expensive. the valve is also not difficult to replace, just set it

Yes, I'm joking))))

It would be better if I hit him with a Karcher)

Sergiy Khabibulin if it were all so simple)))

through the carburetor. Gasoline runs out near the air filter and does not start. floods. tell me what the problem is

Alexander Solopenko just wrote, they brought a calm 180 with the reason it stalls at high speeds, I opened the gas tank cap. I got a familiar smell))) I drained the hell out of this mixture, I’ll clean the carburetor right now

Technician Special Master thank you!

Alexander Solopenko there is a problem with gasoline, at many gas stations they make 95 gasoline from 95, change the octane number, and at the same time we add two-stroke oil. And. Imagine what kind of mixture your instrument eats. I have such a gas station next to my workshop. and the people who refueled there later bring it to me for repairs, but the gasoline there doesn’t even smell like gasoline, either felt like paint, or felt like gas, or some kind of acetyl. and this gasoline does not want to ignite at all, you pull the starter, gasoline enters the engine, but it does not ignite. and you pull harder, thereby flooding the spark plug, after that I unscrew the spark plug, turn the engine over (saw or trimmer) and pull the starter from the cylinder, “gasoline” flows out, with such a smell. I pull until all of it comes out. Then I fill in the new mixture and everything starts, well, I let the tool wear itself out. and then everything is ok! I'll try to make a video about this

Arsenbait, I filled up with gas from another gas station and this problem appeared (leakage from the air filter). I worked on this gasoline for about ten minutes. At the same time, during operation it could only operate at low speeds; when giving gas, the speed decreased and threatened to stall, and at idle the speed spontaneously increased. Or maybe this is a coincidence (different gasoline and the occurrence of this problem)?

Artyom. Candles cost on average 150 rubles. If you took cheap ones, then nothing surprising.

OK thank you very much!

If the spark strikes every once in a while, then the ignition is off, I don’t remember, but on the channel there is how I set the gap on mowers and paddles. worth looking for. check the coil visually, the wire and magnetic parts, whether it touches the flywheel, etc. write me I’ll tell you)

Artyom Kuprin the ignition can be set

Thank you very much, I’ll check, but how can I determine if the coil is bad and adjust the ignition, if anything?

Tell me what can I use to wash it other than carb cleaner. Is it possible with a bucket?

Evgeniy Raevsky Galoshes are not advisable - the elasticity of the membranes will deteriorate, it is better to just use pure gasoline or alcohol

Technician Specialist, is gasoline “galosh” suitable?

Andrey Beleush under no circumstances soak parts in gasoline, except for membranes and gaskets..

It turned out funny. The only reason was the fuel hose that was disconnected. Thank you

. Eventually it stopped starting altogether. What to do?

I bought a “champion” trimmer completely new from the store, I checked it when I bought it and it starts up. I assembled it at home and worked too. The fuel was left over from the store. Then I added gasoline as required. I started it and cranked it a little, but there wasn’t enough power for full throttle and it stalled. Started it up several times the same way.

Any elastic part is called a gasket?

Good afternoon everyone. The third day they are trying to trimmer. What's the problem? For about 20 minutes, half an hour it works like a beast. Then it gradually begins to choke, and eventually kirdyk. I disassemble the carb, blow it out, put it on, and that’s it for half an hour maximum. I thought it was warming up and left it until the morning. Until I get into the carburetor there are no changes. I tried installing a different carburetor. The same. The leader changed the filter. The adapter is on the cylinder too. Also hoses, spark plug. Question. Seals can suck in oil, but not throw out oil? Because it's dry. It's also dry under the cylinder.

after it stalls, unscrew the cap on the gas tank and work for another half an hour or clean the breather, which may be in the cap itself, depending on the manufacturer

Sasha Sh brought me two saws from different areas, but they were filled with gasoline from the same gas station, as it turned out later. As a result, the entire fuel system needed cleaning

Oleg thank you. I've often wondered about the gap. Thanks, I'll take it into account. But the problem was gasoline. I bought it at another gas station, and everything was just as my grandmother whispered.

Sasha Sh set the gap between the flywheel and the ignition coil. Fold A4 paper in two and adjust it to normal

Reference. Read to understand what you are doing!

The required composition (quality) of the air-fuel mixture is adjusted (changed) by turning the screws for adjusting the fuel supply to the intake air flow (right and left). The amount of mixture entering the cylinder is dosed by the throttle valve. If they are turned clockwise, the mixture sucked into the cylinder becomes leaner (less fuel in the air/fuel ratio) and the engine speed increases, while the Husqvarna engine runs softer (weakly picks up speed) and the power drops significantly. In addition, at higher speeds, less oil and gasoline enter the cylinder with a lean mixture (worse lubrication), and this can cause the engine to spoil. Well, the trimmer will have trouble starting. If the screws are turned counterclockwise, the mixture sucked into the cylinder becomes richer (more fuel in the air/fuel ratio) and the engine speed decreases, while at low speeds more gasoline and oil enter the cylinder (better traction, better lubrication), but the Husqvarna engine “spins up” poorly (does not pick up speed well) and more carbon deposits form in the cylinder!

Tips for repairing a gas trimmer carburetor

Regardless of the manufacturer, there are factory defects in trimmer carburetor parts.

For example, the adjustment method described above may not give positive results if the number of turns of the mixture supply screw spring is too large and, as a result, it is impossible to optimally reduce the level of gasoline supplied. To eliminate this, you can shorten the spring yourself a little or purchase a new one in accordance with the instruction manual.

When purchasing oil, many owners of lawn mowers follow the recommendations for preparing the fuel mixture indicated there.

So, often the information on mixing gasoline and oil indicated on the can differs from the instructions in the trimmer's passport. As a result, black carbon deposits can quickly form on the spark plug, which leads to a drop in power and increased fuel consumption. Therefore, when preparing the working mixture, you should follow the recommendations specified in the instruction manual. In most cases, the proportion for a run-in internal combustion engine 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 scythe if the oil portion is reduced and the formation of soot on the spark plug with an increased amount of lubricant.

Correctly performed above tips for setting up the trimmer carburetor will help to avoid not only engine overheating and increased fuel consumption, but will also significantly increase the service life of other parts and components of the tool

Pay attention to the operation of the lawn mower in all modes and carry out scheduled maintenance and repair of the tool on time.

From personal experience

Petrol mower or trimmer

A trimmer is a broader concept than a lawn mower, since it can also be electric. A gasoline trimmer and a gas trimmer are one and the same.

Some authors claim that a trimmer is a weaker tool, in contrast to a more powerful lawn mower, which can be used for mowing bushes. Personally, I have a tool with a maximum power of 1.7 kW and, as stated in the instructions, capable of mowing small bushes up to 10 mm thick. The user manual is called “Gasoline trimmer...”.

Fuel mixture proportion

I read somewhere that if the operating manual for the lawn mower and the oil canister indicate different proportions for preparing the fuel mixture, you should use the proportion indicated in the manual.

For a long time I did this - excess oil flowed from the engine onto the gas tank and carbon deposits constantly formed on the spark plug, since the manual indicated the proportion for a run-in engine was 1:25, and on the canister - 1:50. After switching to a ratio of 1:50, the appearance of oil drips stopped. The spark plug continued to burn, but with less intensity (the carburetor was not yet adjusted).

Until now, some users of gas-powered tools determine the proportion of the fuel mixture “by eye.” If the amount of oil is underestimated when preparing the mixture, after some time an extraneous sound may appear immediately after starting the engine, which gradually disappears during warm-up, and the engine stops with a sharp jerk. Continuing to operate the trimmer in this mode will result in its failure.

Cleaning the spark plug

During the worst times of running a trimmer with an unadjusted carburetor, the engine would stop starting after using each tank of fuel. And only after cleaning the spark plug from carbon deposits could work continue.

Fine sandpaper was used to clean the electrodes, and a thin paper clip with a bent end was used to clean the space between the insulator and the housing. First, the electrodes were wiped from large dirt with a rag, then cleaned with sandpaper. After this, the candle was lowered into diesel fuel and the moistened carbon deposits were scraped off with a paper clip from the surfaces of the insulator, the inside of the body and between them. Next, the candle was dipped into diesel fuel several times, which was then shaken off along with the dirt. Sometimes the paperclip cleaning and rinsing procedure was repeated. After this, the candle was wiped dry and was ready for further use.

Incredibly, one tank of fuel mixture with an unadjusted carburetor can be used up in less than 10 minutes - tested in practice when the trimmer was started and operated at high speeds with maximum fuel supply (the adjusting screw was unscrewed much more than normal).

Model description

The above-mentioned equipment option costs RUB 13,490. It is a premium device. With its help, you can take care of the territory on a large suburban site. The equipment can handle young and old grass, reeds and weeds, as well as young bushes.

The petrol mower "Stil FS 55", reviews of which you can read below, has a powerful 1 liter engine. With. The device is ideal for use in a suburban area or country house. In one pass you can mow 420 mm of grass in width. This device is suitable for hardware processing of the lawn, mowing grass and allows you to even walk along fences, process narrow areas and areas near flower beds. The tank holds 0.33 liters of fuel, which will be enough for uninterrupted operation for half an hour.

Elimination methods

The list of upcoming work on the engine may be as follows:

replacing the fuel pump;
disassembling and washing the strainer;
replacing the adjustment lever;
it is also necessary to clean the adjustment space;
replacing the membrane (or the entire block where this membrane is located);
adjusting intake, exhaust and needle valves;
replacing dampers;
cleaning fuel channels and diffuser;
replacing screw springs;
change of primer.

Not all of these jobs can be completed. It often turns out that many of them are not needed if a specific malfunction is immediately detected.

The spring may interfere

My first attempt to adjust the carburetor of the lawn mower did not yield anything, since the spring of the fuel mixture adjustment screw was in the way.
The factory spring turned out to be too thick when compressed and did not make it possible to reduce the fuel supply to the required level. I had to pick up another spring and continue the adjustment after replacing it. Fuel mixture supply adjusting screw with spring

In the photo above there is a factory spring, below there is an adjusting screw with a selected spring. I’m writing about this because I’m not sure that this is an isolated case and that someone else may encounter the same situation.

Petrol mower device

The structure of the Shtil FS 55 lawn mower should be clear to you 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 a chainsaw. But the last tire is fixed to the motor gearbox with a long tubular rod. Inside there is a shaft that transmits torque from the motor to the working tool. This design is suspended on a belt that is thrown over the shoulder. This allows you to hold the tool suspended, which is important when the weight of the chainsaw is sensitive.

A handle is fixed to the rod of the unit, with the help of which you can move the end of the rod with working equipment. The petrol mower "Stil FS 55", a repair manual for which is presented in the article, has a protective shield on the human side in the form of a casing, which prevents injuries during operation. The instrument itself is a round drum with a thick fishing line coming out of holes on both sides of it. Adjusting the carburetor and chainsaw repairing lawn mowers Stihl fs55 fs 38 carburetor. When the drum spins, the line is pulled under the influence of centrifugal force and hits the grass, cutting it.

The Shtil FS 55 petrol mower, the technical properties of which will be presented to your attention below, has a fast-wearing nylon line. Features of the Stihl fs 38 lawn mower, adjusting the carburetor of the Stihl fs 38 lawn mower. It is sometimes updated by the method of unwinding the coil, which is located inside the drum.

Malfunctions and their elimination

Electric and gasoline trimmers experience typical breakdowns and malfunctions. For devices powered by an internal combustion engine, these are:

problems in the carburetor;
engine breakdown;
problems with the fuel system;
breakdown of the gearbox, starter, muffler;
blockages;
air filter failure;
problems with the ignition coil.

Electrical units have specific breakdowns:

problems with the control button and electrical cable;
burnt out motor stator winding;
broken contacts.

For simple problems, you can repair the trimmer yourself.