What to do

Builders, installers, rescuers and gardeners - all of them, sooner or later, in carrying out their tasks, take up a chainsaw. And the end result of their activity largely depends on how reliably this tool will work.


Chainsaw is used to cut wood.

It is worth noting that the chainsaw belongs to relatively simple devices. Nevertheless, it, like other mechanisms, periodically fails. When a chainsaw stalls, working at idle (this is one of the most common malfunctions), the biggest problem is to determine the reasons for this behavior of the device. If the source of the “disease” is correctly established, it will not be so difficult to return the device to a working position.

Therefore, the first thing you need to find out what are the malfunction of a chainsaw and that leads to engine stops at idle.

The car stalls at idle: possible causes

In order to answer the question of why the saw, occasionally naughty, stalls at idle, one must bear in mind that this tool is based on an ordinary two-stroke internal combustion engine.

Chainsaw device

Chainsaw device.

From this it follows that malfunctions are caused by various problems with the main components of any internal combustion engine: fuel and lubricants, the ignition system, the quality of the air-fuel mixture and compression inside the cylinder.

The main engine failures include the following:

  • the motor does not start;
  • it starts up, but, working unstable, quickly stalls at idle;
  • The chainsaw is working normally at idle, but it stalls under load.

The causes of violations of idling can be different. But all of them can be reduced to several common positions. So, problems such as:

  • Internal Combustion Chainsaw Engine

    Engine chainsaws internal combustion.

    possible clogging of the fuel and air filter;

  • defect or malfunction of the spark plug;
  • violation of the initial settings of the carburetor, caused by strong vibrations during the operation of the mechanism;
  • pipeline defects;
  • wrong ratio of ingredients in the "fuel mixture";
  • muffler pollution;
  • malfunctions of the cylinder-piston group.
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Malfunctions of the fuel and air filters and their elimination

The chainsaw will stop at idle if the fuel filter or air filter becomes clogged. To find out the status of the first element of the fuel system, you should disconnect the gas line from the carburetor. If during pumping the fuel comes in doses that meet the specified standards, then the cause of the malfunction is to look elsewhere. If gasoline comes to the carburetor weakly or does not flow out of the hose at all, then most likely the filter is clogged with debris.

For cleaning, it is removed from the tank (all fuel must be drained from the tank until this point). Extraction takes place through the filler neck of the tank with a wire hook. The filter is disconnected from the suction hose. If possible, the filter is cleaned. If there is no such possibility or it is inexpedient to do this for a number of reasons, the used filter is changed to a new one.

Fuel filter chainsaws

The chainsaw may be stunned if the fuel filter is clogged.

The air filter can also be clogged with dirt or dust, which leads to malfunctions at idle. It should be remembered that the clogging of this filter occurs quite often, as a result of which the flow of air into the system becomes difficult. In the fuel-air mixture, the proportion of gasoline increases, and it turns out to be too enriched. Normal operation of the engine in this case can not be expected.

For cleaning, remove the air filter with extreme care so as not to shake off the dust in the carburetor. Then it is cleaned and washed thoroughly. Detergent is added to the wash water. After drying, the air filter returns to its place in the chainsaw.

For normal operation of the cutting tool, it is recommended that the fuel and air filters be changed every 3 months.

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Spark plug problems and solutions

Usually this key component of the ignition system is recommended to be replaced at least once a year. But often the owners saws forget about this rule. And therefore, it is not surprising that the device, the maintenance of which is conducted fragmentary, as a result, badly “keeps” idle.

Chainsaw Spark Plug

Spark plug chainsaws need to be changed 1 time per year.

Therefore, you should pay attention to the following problems associated with the operation of this system:

  1. Pouring gasoline candles at the time of launch. To eliminate the problem, turn out the candle and dry it without burning it. Through the hole-nest into which the candle is screwed, excess gasoline is drained from the engine. After a break of 30 minutes, the candle is set in place, the mechanism starts.
  2. No spark due to poor contact of the spark plug with the high voltage wire. The connection is checked, in case of violation the defect is eliminated.
  3. Spark is missing due to malfunction of the electronic ignition unit. If there is confidence in the connection of the tip with the high-voltage wire, but there is still no spark when the starter is on, then the ignition unit may be the cause of the breakdown. This component is not restored, it is only changed to a new one.
  4. Wrong gap between the candle electrodes. In different types of candles, this indicator ranges from 0.2 to 0.5 mm. The correct clearance is set using a gauge of the appropriate thickness. Greater or smaller clearance for a given type of candle is not allowed.

Meanwhile, during the initial inspection of the spark plug, it may become clear that the reason why the chainsaw refuses to work does not lie in the defects of the spark plug or other elements of the ignition system.

Spark plug

Spark plugs can tell about the failure of the saw.

So, if the candle turns out to be completely dry, it may mean that the original problem lies in the impossibility of the fuel entering the combustion chamber. In this case it is necessary to check the entire petrol supply chain from the carburetor itself.

At the same time, the presence on the body of the candle of a characteristic soot of black color is a sign that, probably, the carburetor is badly adjusted. Because of this, the fuel mixture is oversaturated with gasoline. Oil may have entered the fuel. In this case, clean the spark plug, replace the fuel and adjust the carburetor.

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Unconditioned carburetor work

If by experience it turns out that the filters are clean and the ignition system is not to blame for the fact that the chainsaw is not able to operate at idle, the owner of the tool is recommended to switch his attention to the carburetor.

Chainsaw carburetor

It is necessary to disassemble and assemble the carburetor without haste, as there are many details in it without which it cannot work.

Often, the imbalance of this unit, which is responsible for supplying a certain volume of air-fuel mixture to the engine cylinder, leads to unstable operation. It can be adjusted with three special screws located on the carburetor: screws with maximum and minimum turns, and also with a screw controlling idle turns.

Some manufacturers, fearing undesirable interference from incompetent people, supply their products with only one screw of the idle year. But in both cases, the adjustment of the carburetor can be made only by accurately following all the manufacturer's instructions.

However, after adjusting the carburetor, in accordance with factory standards, this site can act up. Then it is recommended to clean the fuel and air channels, jets, mesh filter element. If the membrane is damaged, it must be replaced with a new and high-quality.

Being engaged in the maintenance and repair of the carburetor, you should always remember that it is usually stuffed with many very small details, without which the device simply can not work normally. Therefore, the carburetor should be disassembled and assembled without haste and with special care.

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Problems related to incorrect operation of the fuel system

The chainsaw periodically stalls at idle also as a result of a violation of the integrity of the fuel line or an incorrect ratio of the ingredients of the “fuel mixture” consisting of gasoline and oil.

Before each switching on of the cutting mechanism, it is necessary to visually inspect its blocks and assemblies, paying attention to possible defects in the surface of the body, mechanical damage, and leakage of working fluids. This should be done in relation to the fuel pipe saw, which is usually a rubber tube.

If the device was (especially for a long time) in a damp place and it had to withstand sharp fluctuations in air temperature, this tube could simply crack. Such a fuel line is not suitable for further use and should be replaced.

Another reason why a chainsaw at idle can stall is the non-compliance of the ratio of ingredients in the preparation of the "fuel mixture". The proportions of gasoline and oil included in it must correspond exactly to the original instructions for a particular device. If they are not complied with, the engine will not be lubricated sufficiently, and the whole mechanism will persistently stall.

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Idle problems due to faulty muffler

In the case of a noticeable drop in the power of the internal combustion engine at idle mode, after which the car often stalls, it is necessary to recall checking the silencer. The fact is that the specified site can be heavily clogged with resinous particles and products of combustion of the extinguisher of sparks falling on the walls of the muffler in the form of thick sediments.

As a result, the formed impermeable layer interferes with the normal exhaust of exhaust gases. Such a situation must necessarily be corrected. Easy repair clogged muffler as follows.

Chainsaw silencer

Dry cleaning of the muffler is not allowed, as carcinogenic carbon particles can get into the respiratory tract.

The muffler is removed from the engine, disassembled (if this type of muffler can be disassembled). It is necessary to block the remaining holes from under the muffler.

The entire knot and its individual parts are thoroughly washed with a rag dipped in water with detergents. If the muffler is collapsible, waiting for the complete drying of all its parts. The knot is dried using ordinary household hair dryer. Cleaning of this device with a dry cloth is not allowed, otherwise carcinogenic particles forming carbon may get into the human respiratory tract.

As a preventive measure for the normal functioning of a two-stroke engine silencer in the “fuel mixture” of chainsaws, it is recommended to use only high-quality oil and only that prescribed by the manufacturer of this unit.

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Malfunction of the piston group

It is possible that after elimination of all the listed causes of malfunctions, the chainsaw will continue to stall at idle or not at all. In this case, you have to look into the heart of the engine - its cylinder.

Sometimes even a visual inspection is enough to determine what is with the cylinder-piston group. Chips, scoring, obvious wear of the cylinder and other visible defects are direct obstacles to the normal operation of the device. Without a doubt, such parts must be replaced.

If there is no obvious damage, then piston rings should be examined. Damage to these rings leads to a loss of engine power. Too free running of the rings in the grooves of the cylinder means that it’s time to replace these parts with new ones.

Meanwhile, a complete picture of the technical condition of this group of parts can be made only after a complete engine analysis. Since this is a laborious, responsible business that requires a certain professional experience, it is better to entrust it to a specialist. This is the only way to extend the working age of a great human helper - chainsaws.

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