Husqvarna 128 R Trimmer Does Not Turn Up

Carburetor for trimmer. One of the most important units of the unit, which is responsible for the fuel mixture. If the equipment is improperly handled, the element may be damaged, which is why it is impossible to operate the lawn mowing without repair. To repair a garden tool, you need to know about its structure, the principle of operation and the rules of adjustment.

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

Structurally, carburetors from well-known brands and Chinese manufacturers are practically no different.

The carburetor device for lawn mowing consists of the following elements:

  • Booster pump;
  • Atmospheric membrane tuning systems;
  • Primer, facilitating the start of the motor;
  • Cold running systems;
  • Elastic two-valve plate;
  • Metered system with a rotating rotor;
  • Throttle

The model operates as follows:

  • From the air damper, air passes into the tube, which increases or decreases its flow;
  • In the area with an opening for the fuel mixture, the narrowed zone is the diffuser. In this zone, air moves faster;
  • The fuel mixture from the float compartment through the nozzle enters the tube. The amount of fuel is determined by the float;
  • With enhanced airflow, fuel is picked up and sprayed. 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 airlock is open, and accordingly, more fuel is supplied to the cylinder. Regulation of the carburetor of the lawn mowers is to set the correct ratio of the dampers to achieve the optimal consistency of the fuel mixture.

When is carburetor adjustment required?

The operator needs to adjust the work node in certain cases:

  • The new engine was run in using 4-5 liters of fuel;
  • Changed the composition of the fuel. the brand of motor oil and gasoline;
  • Weather conditions have changed (in winter, summer);
  • The level of rarefaction of air has changed;
  • The load on the power plant increased;
  • After prolonged storage of the unit;
  • The formation of persistent soot on the spark plug;
  • After starting, the motor stalls immediately or does not develop the required speed;
  • When vibrating, the tuning screws loosened;
  • The amount of fuel consumed has increased;
  • Gasoline is not pumped into the cylinder;
  • It turns out a lot of exhausts.

How to do the adjustment of the carburetor lawn mowers with your own hands?

Before setting up the carburetor assembly, 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 dipped 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 gas engine should run idle for at least ten minutes.

If the cutting headset continues to rotate at idle, it is worth reducing the speed of the power plant. The operation of the T screw is adjusted, on some models it is marked LA. The idle speed control is twisted counterclockwise until the cutting element stops moving.

The trimmer carburetor adjustment is dependent on three screws:

  1. L is responsible for the level of pumping the fuel mixture at reduced speeds. It is set up first. It is necessary to achieve maximum speed by unscrewing the screw to the desired point. After the regulator turns a quarter of a turn to the left;
  2. T (LA). sets idle operation. When you turn the screw to the left, the engine speed decreases, to the right. increase;
  3. H allows you to enrich the fuel at maximum speed. The screw adjusts high revs, fuel economy and power plant power level.

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

Eliminates engine damage proper tuning:

Husqvarna 128 R Trimmer Does Not Turn Up
  1. With the engine running, give full throttle;
  2. The screw N is unscrewed clockwise until the unit starts to slow down;
  3. Knob H rotates to the left until the motor is stable.

If you follow all the instructions, the carburetor for lawn mowing is considered tuned: the engine runs at the required speed, slightly quadruples at high speeds, the cutting elements do not rotate without load.

Funny pencil

Do it yourself with your own hands at home


How to start the lawn mowing engine.

Faulty carburetor 2t-engine lawn mowers.

How often do we manage to start the lawn mowing engine, which in all external parameters can be considered serviceable? This happens often, even at the most inopportune moment.

We do not find defects in the engine design. The fuel mixture is composed correctly and based on fresh ingredients. Sparking is present. The carburetor mode settings were not changed, but the engine of our lawn mowers still does not start. Why?

Each product of the technical industry has units or parts that have either fine-tuning or high dimensional accuracy when manufacturing and when placing them in the finished product.

Most modern 2t low-power engines are equipped with carburetors with the ability to control modes, depending on the fuel used and the condition of the engine. The design of carburetors may differ among themselves, but the principle of operation of the carburetor, the formation of a fuel-air mixture, remains the same.

Read more:  How to Dress a Reel on a Trimmer Video

In order for you to understand the meaning of the following description, I will say that in case of any malfunction, some owners give the product for repair and do not load their heads with an unnecessary problem.

Others buy a new one or carry out repairs with a partial replacement of components, and most of the owners of faulty chainsaws or lawn mowers independently carry out diagnostics and repairs, determining step by step the cause of the malfunction. Someone is interested and informative, but someone does not have enough time and money for after-sales service.

In the beginning, I want to pay attention to some signs that indicate a faulty unit or element of a similar carburetor.

  • A working, compacted lawn-mowing engine is started only when several grams of the fuel mixture are poured into the working chamber through the spark plug hole or through the open carburetor diffuser. (!) I’ll clarify that the discussed engine is working and it will start, but for a few seconds.
  • Engine with reduced compression ratio in the cylinder, there is a significant production of piston rings or one of the crankshaft oil seals is not tight enough, nor will it start in the usual way (!). A test run of such an engine with the addition of fuel directly to the piston chamber makes sense, since with a working carburetor such an engine can start and can continue to work, but it can be restarted in the usual way no later than a couple of minutes after it stops, while the volume of the crankcase and cylinder contains the unsettled fuel-air mixture.

To make sure that there is no mixture formation, it is possible to spray a little fuel mixture in front of the window of the carburetor diffuser just started by the engine described above, using a medical syringe. The engine will run until you provide fuel to it.

In this case, feel free to change the carburetor or start repairing the existing one, which I write about here and wrote earlier:

Petal valve fuel atomizer carburetor 2t-engine lawn mowers.

Each part of the carburetor must be carefully disconnected from the adjacent element and carefully inspected.

  • Check the tightness of the carburetor parts through the gaskets. Tightness may be impaired due to gasket defects, loosening of assembly and mounting bolts.
  • If there is no fuel in the carburetor’s fuel chamber, check the passage and tightness of the channel through which the pressure of the fuel pump membrane is controlled from the crankcase. Check the primer’s membrane and mushroom valve, if any.
  • If there is fuel in the carburetor’s fuel chamber, then this is exactly the case when owners desperately change the carburetor for a new one without knowing the reason, because they can’t start the engine.

In this case, the reason lies in the last segment, in front of the hole of the fuel atomizer, where its valve is installed, which is made of rubberized fabric and the channel controlled by it can be closed, which rarely happens, or is still open.

The opening of the spray channel, as a rule, is always open when the spray valve is faulty, and no matter how hard you try to start the engine, you will not succeed. A serviceable valve opens only when there is a clear discharge and closes when it is absent. If the valve is faulty, fuel will not flow under the nozzle opening at the moment when the fuel-air mixture should form. And here is why it can be faulty, read on.

The entire valve consists of a bronze glass, at the bottom of which there is a seat for the valve itself. A locking ring with restrictive protrusions is installed on top of the glass. The active element inside the valve is a round petal made of rubberized fabric.

Video: Husqvarna 128 R Trimmer Does Not Turn Up

In the locking state, the petal rests on the saddle and closes the fuel channel. In the open state, the petal is raised and is located at the locking ring itself, but the fuel channel in front of the atomizer is not blocked, since the restrictive protrusions on the ring do not allow the petal to press against the hole and block the entire surface. Fuel at this moment enters the atomizer.

As a rule, the engine of your scythe works at high speeds, otherwise the centrifugal clutch will not work and the cutting knife of the scythe will not have enough power. It is so?

And this is so, which means that the valve petal will move synchronously with the engine piston and with that greater force will hit the saddle and the restrictive protrusions, for how manýThe largest differences between pressure and discharge in the carburetor diffuser will occur at high engine speeds.

Gradually, with each hour, the valve petal wears out and there comes a moment when the engine of the lawn mowers stops and no longer starts up at any attempts, except for the verification methods I have indicated earlier. The integrity of the petal is violated and it seems that someone intentionally pierced the petal.

The most interesting thing is that not everyone can take into account this cause of a faulty carburetor and mislead itself about other possible causes of a malfunction of the engine itself.

I assure you that it is possible to restore the carburetor atomizer valve, and this can be done quickly and easily. Watch the video.

We take a membrane from the automobile fuel pump (gasoline) and a drift. You can carefully cut the petal with scissors, but few will get it. The punch in our version is one of the knees of a suitable diameter of the telescopic antenna of the radio receiver.

On a wooden or rubber surface with a punch, we cut out the petal from the membrane of the automobile pump, remove the valve locking ring, change the petals, carefully lock the valve with the ring and assemble the carburetor.

Read more:  "Oleo-Mac" Trimmer Review.

A working engine starts up as if nothing had happened.

Carburetor fuel spray needle M215-040.

The type of carburetors used on lawn mowers with 2t engines is vacuum and needle. Vacuum is understandable, but needle-shaped because the amount of fuel supplied by the atomizer to form the mixture is controlled by a metal rod called a needle.

In the design of some carburetors, the shape of the rod is conical, while other carburetors are equipped with a metering needle in the form of a conventional metal rod. The fixed position of the metering needle for all carburetors is set differently.

Who remembers or knows for sure that the amount of fuel supplied by carburetors on our motorcycles could be changed by fixed needle positions? Below the octane number of gasoline. the needle is higher, the high octane in gasoline. lower the needle. We enrich or impoverish the fuel-air mixture.

Over time, with prolonged operation of the engine, the needle breaks the spray channel a little, and whether you want it or not, you have to lower the needle a little, thereby impoverishing the fuel-air mixture. You can install a needle with a larger diameter and longer length.

We have cases when handling problematic braids, on the carburetors of which adjusting bolts of a fixed position of the spray needle were turned out. For the sake of curiosity, they rely on a certain jet. You will return everything to its place and the engine can be freely started.


The trimmer for giving

Husqvarna Trimmer Carb Adjustment

Annotation on adjusting the carburetor lawn mowers.

Carburetor adjustment and repair

The trimmer does not belong to complex household appliances, because most of its failures are mechanical in nature and can be successfully removed with their own hands. Even if the engine fails for severe reasons. damage to the piston ring, for example, repair is reduced to replacing the part.

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

Principle of operation

Carburetor. a power system module in which liquid fuel and air are mixed before being fed into the engine cylinders. Depending on the tool and its operating mode, mixing and feeding are adjusted appropriately.

The carburetor device of the lawn mowing is uniform for virtually all cases. It belongs to the category of float devices. The latter provide constant characteristics of the finished consistency.

The mechanism of the module is as follows.

  • Air enters the body of the tube with an air damper. 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 constriction. a diffuser. Here the flow rate increases.
  • Fuel from the float chamber through the nozzle is fed into the tube. The float level determines the amount of fuel supplied. Because the pressure in the chamber is normal, and the pressure in the tube is low due to the greater dilution of air, gasoline is sucked through the nozzle.
  • Accelerated airflow picks up fuel and atomizes it, forming an air-fuel mixture of suitable density.
  • The mixture is sucked into the cylinder through a pipe.

The stronger the air damper in the tube is open, the higher the density of the air flow, which means that more fuel enters the cylinder. Setting the carburetor of the lawn mowers is reduced to setting such a ratio of the dampers at which the density of the fuel consistency becomes good.

Signs of imbalance

Carburetor debugging is certainly done in the manufacture of the apparatus. Usually, the owners will find out about the need to adjust the fuel supply with their own hands only after quite severe breakdowns, during the correction of which the module was removed and, for example, cleaned.

Signs of a failure in the settings are as follows:

  • it starts up, but the motor stalls here. since the engine can only work when a certain amount of gas is supplied, with very “poor” fuel, in other words, blocking the supply channel, the motor will stop;
  • very high fuel consumption, a lot of exhaust gases. the result of incomplete combustion of consistency. In this case, there is a lot of fuel, and the mixture comes out extremely dense.

Read the same

Adjustment carburetor lawn mowers Husqvarna 125, 128

Husqvarna 125R carburetor tuning without tachometer (temporary solution)

How to adjust carburetor,if you need to work, and the 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 disorder of the work is a violation of fixation. due to vibration or damage to the protective cap. Such a breakdown can be detected simply by trying to turn the screw a little: if the fixation is not rigid, it is worth checking the setting.

DIY carburetor adjustment

The configuration of the module does not apply to repair and replacement of spare parts is not required. In this case, the repair kit for the carburetor lawn mowers will not be needed.

There are three screws 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. with its help idle debugging is carried out.

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

  1. Setting up the module is carried out only when the engine is warm: for this, the device is first turned on for 10 minutes. If the mowing head rotates at idle, then proceed with debugging immediately: turn screw T counterclockwise until the rotation stops.
  2. Adjustment starts with screw L. The screw rotates left and right until it finds its position at which idle speed does not become maximum.
  3. Then turn the screw на turn counterclockwise. This will be his working position.
  4. Idling must be adjusted by turning counterclockwise to increase the speed and clockwise to decrease. Its debugging consists in the achievement of such a mode in which a sufficient number of revolutions is made before the mowing head begins to rotate. In this case, the engine must work stably in different positions.
  5. The position of the screw L is determined last. at maximum speeds 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 established by ear.
  6. Then, the screw also rotates slowly counterclockwise until the motor starts to malfunction. Then the screw is turned back clockwise until the engine starts working again normally.
Read more:  Hitachi Petrol Trimmer Not Reaching Cause

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

6 comments on the post “Adjustment and repair of the carburetor lawn mowers”

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

tell me the initial position of the screws H L LA


tell me the initial position of the screws H L LA

DIY gas trimmer repair

The presence of a gas trimmer significantly simplifies the life of those who often have to mow grass around the house or in the garden, as well as harvest hay for animals. However, the simplicity of operation does not exclude the occurrence of malfunctions, moreover, the complexity of the mechanism entails the complexity of the repair. And after-sales service imposes additional costs on the tool.

In order to extend the life of the tool, preventive measures are necessary. So, for example, do not overload the device, every time after 15 minutes, take a 10-minute rest. Do not neglect the rules of operation and do not mow the grass, the height of which exceeds the permissible. If a breakdown occurs, do not rush to contact the after-sales service, inspect the device to determine the cause, maybe it is possible to actually repair the gas trimmer with your own hands, especially if you have some skill in working with the equipment.

First, find out how to independently find the cause of a device malfunction, then talk about why these breakdowns occur and how to fix it.

How to find a breakdown. symptoms

Despite the fact that the gas trimmer is a complex device, some breakdowns can be found and easily fixed without the help of a service center or a wizard.

Here are some ways to diagnose a breakdown at home:

  • First, check the spark, because without it there will be no ignition. If there is no spark, then the problem is in the spark plug, or in the ignition itself;
  • Also, if the candle is dry, you probably need to repair the fuel supply or clean the carburetor;
  • If the candle is filled with fuel, then wipe it dry and try to start the tool again;
  • If everything is in order, but the tool does not work, then most likely the problem is in the engine. If you do not know how to fix this part of the tool, then it is better to take the gas trimmer to the service.

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

Frequent malfunctions

If you make a list of breakdowns that owners of gasoline trimmers most often encounter, it turns out like this:

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

Below we will try to help those who want to fix the gas trimmer with their own hands using improvised tools.

Check the gas trimmer spark plug. is it dry or in fuel?

Causes of breakdowns and repair methods

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

Now a few recommendations that will help you fix the breakdown and repair the tool yourself.

DIY repair tips

To ask yourself as little as possible how to repair an engine, carburetor, or gearbox of a gas trimmer with your own hands, do not purchase rare models, as it will be extremely difficult to find details for them, and at official dealers the prices do not always correspond to the capabilities of buyers. If you are new to working with complex technical products, it is better to contact a service representative for help. self-adjusting the carburetor, for example, can subsequently lead to the combustion of the entire piston system. In addition, some parts cannot be repaired at all, and an entire unit is subject to replacement; repairing one yourself in this case will not make sense. Also, do not rush to open the tool body, if it is under warranty.

To help, we can offer you to turn to the services of a master for repairing trimmers, which can be found on one of the sites, for example, LINK (do not forget to choose your city). At least, if the repair is carried out by the master, you can be sure of the result.

New gas trimmers