The chainsaw does not start well and stalls

Chainsaw starts and stalls reasons

Why does a chainsaw stall under load

In some cases, the chainsaw under load is unable to work normally and simply stalls. A common reason for this behavior is improper carburetor adjustment, or air leaks through the crankshaft oil seals or carburetor gasket. And also this behavior can occur due to leaks in the carburetor.

It is best to diagnose the cause and eliminate the fact that the chainsaw starts and stalls under load, best of all in a service center, since a special tool is needed to check the tightness of the carburetor and crankcase.

A saw that is unable to operate under load will also be unsteady at idling. They will “float”. Diagnostics begin with a check for leaks in the crankcase and carburetor. If air leaks through the crankshaft oil seals, they must be replaced. If air leakage in the carburetor is detected, the cause can be eliminated by installing a repair kit of gaskets.

Chainsaw Won’t Start (Easily Fixed) Must See!

chainsaw, does, start, stalls

Only after the above actions have failed and the crankcase with the carburetor is sealed, you can proceed to adjust the carburetor.

The reason for this algorithm is as follows, if air leakage from the crankcase is not eliminated, but the carburetor was simply adjusted to normal engine operation, then the fuel mixture will contain more fuel than is required with a sealed crankcase, which in turn will significantly increase its consumption. Also, most likely, carbon deposits will appear in the engine, which will also negatively affect the further operation of the chainsaw.

In some models of chainsaws, to ensure the operation of the fuel pump, special hoses are installed that transmit an air impulse from the engine crankcase to the carburetor fuel pump. If this hose is frayed, the saw will idle unevenly and will not work at all under load.

Owners of HUSQVARNA 137 and HUSQVARNA 142 household chainsaws should first of all check the impulse hose for any deviations in engine operation from the norm, since this is considered the most common reason for the breakdown of these chainsaws.

A video showing how to replace a defective impulse hose with your own hands on a HUSQVARNA 142 chainsaw can be viewed below. It shows step by step the process of disassembling the saw, shows the impulse hose and stipulates the consequences of its malfunction HUSQVARNA 142.

When tilted

If the saw does not develop speed when tilted, shuts down, stops working, you need to check the fuel level in the tank. If it is not too high, the tilted device is not supplied with sufficient fuel because the fuel pipe is above the mixture level.

Why not start a chainsaw. causes and remedies

Over time, the working mechanisms of the garden tool wear out, resulting in various chainsaw malfunctions. To fix them with his own hands, the operator must quickly determine the cause of the breakdown and replace the faulty part.

Chainsaw starts normally, but stalls when gas is added

One of the most common breakdowns of a household chainsaw is to work only at idle speed, and instant failure when you press the standard gas trigger.

There can always be several reasons for this malfunction:

  • clogging or initially incorrect adjustment of the standard carburetor. in this case, you will need to clean the unit and adjust it according to the instructions in the operating instructions;
  • the basic air filter of the tool being used is clogged. because of this, air does not enter the saw carburetor, which leads to a gradual loss of power;
  • clogging or wear of the fuel filter. as a result, the part is not able to pass the amount of fuel that is necessary for the engine to speed up.

If the chainsaw works fine at idle, but stalls under load, then the first thing the owner should do is check the condition of the filters. Only then can you start setting up the carburetor.

Chainsaw stalls under load. reasons and solutions

A common reason a saw stalls when thrown is due to improper setting of the factory carburetor. Another sign of a malfunction is increased air leakage through the holes in the carburetor gaskets and oil seals located next to the crankshaft.

To eliminate this malfunction, it is best to take the chainsaw to a service center, since special devices will be required for diagnostics. If this is not possible, then you can try to fix the problem yourself. To do this, you will need to disassemble the carburetor and check its tightness. You also need to inspect all seals and gaskets. If necessary, all worn seals will need to be replaced.

If the cause of the malfunction is not a poor condition of the oil seals, then you can begin to adjust the standard saw carburetor.

Malfunctions leading to improper operation of the chainsaw

There are a number of faults that must be taken into account when diagnosing, since they can lead to interruptions in the operation of the saw.

  • Worn crankshaft bearings. With worn out crankshaft bearings, runout is inevitable on the main shaft, where the flywheel is attached. In such a situation, it is impossible to adjust the gap between the flywheel and the ignition coil, which entails interruptions in sparking, and unstable operation of the chainsaw.
  • Impulse channel contamination. The impulse channel serves to ensure the operation of the fuel pump, respectively, its contamination leads to improper operation of the pump, which will make it impossible for the saw to work (it will start and immediately stall).
  • CPG wear. As a rule, with increased wear of the CPG, there is a decrease in compression in the engine of the chainsaw, which will necessarily affect its ability to develop speed.
  • Dirty fuel and air filters.

Checking the spark on the spark plug and eliminating the causes.

The first step in looking for reasons why your gasoline saw won’t start is to check the spark on the spark plug. There are many factors that affect the performance of this element. However, the main ones at the initial stage of instrument troubleshooting are:

  • Incorrect carburetor adjustment;
  • The presence of more than it should be, the amount of oil in gasoline;
  • Clogged air filter.

All of them contribute to the formation of carbon deposits on the spark plug electrodes. In 50 cases out of 100, the saws do not start on a cold one due to the absence of a spark due to carbon deposits on the electrodes and their corrosion. As a result, the gap either decreases or increases.

It is quite easy to check for a spark. This will require:

  • Remove the tip of the high-voltage wire;
  • Unscrew the candle;
  • Put the tip back on;
  • Lean the candle with a skirt against the cylinder;
  • Start with a starter.
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If a good spark is observed between the electrodes at the time of starting the engine of the chainsaw, then everything is in order with the ignition unit. If it is not there, then it is worth cleaning the element itself and checking the gap of the electrodes. If necessary, use a special probe to adjust the distance between the contacts.

For candles from different manufacturers, the distance between the electrodes may fluctuate. For some, it may be equal to 0.5 mm. Others have 0.2 mm. Therefore, carefully study the manufacturer’s recommendations.

There may be no spark on the spark plug for other reasons. Of the main faults affecting the poor start of the chainsaw and the unstable operation of the internal combustion engine at idle, from which the tool can stall, the following can be attributed:

  • Overflow of the spark plug channel with fuel;
  • Lack of contact between the high-voltage cradle and the tip of the candle;
  • Failure of the ignition unit.

How to start a cold chainsaw if the spark plug channel is constantly flooding with gasoline? To eliminate the problem while starting the tool, you can use the following algorithm:

  • Unscrew the candle with a special key;
  • Wipe it with a clean and dry cloth;
  • Dry for 20. 30 minutes;
  • Remove carbon deposits with a file and adjust the gap between the electrodes;
  • Drain the remaining fuel from the spark plug channel and dry it;
  • Collect everything and try to start the mechanism.

As a rule, these measures are enough to start the chainsaw and get the job done. However, this extreme measure does not eliminate the main reason why the engine does not start or stalls. improper operation of the carburetor, which needs fine adjustment.

If there is no spark and poor contact of the high-voltage cradle with the spark plug tip, check the connection. The check can be carried out using a conventional tester. If a defect is found and it is eliminated, the chainsaw should start without any problems.

If the check showed that the contact is reliable, and the saw does not start further, look for the cause in the ignition unit. As a rule, a faulty unit cannot be repaired and restored. A complete replacement is required here.

How to start a chainsaw correctly?

Before starting the tool, you need to read its instruction manual. The instructions for some models indicate that the inertia brake must be applied to the chain to stop immediately before starting the saw. Thus, starting the tool will be safer for the operator. However, starting the saw will be much more difficult when the brake is on. In practice, it is best to start the saw with the brake disengaged, while adhering to the safety rules.

To properly start a cold chainsaw, you need to follow this procedure:

  • The first step is to move the throttle adjustment lever to the lowest position. It should be noted that the lever can only be moved to this position when the throttle lever is pressed. This will close the carburetor throttle valve. To perform further actions, the throttle lever must be fixed in the pressed position;
  • Then you will need to pull the standard starter rope sharply several times. This must be done until the saw motor starts, and after that it stalls. Next, the flap position lever must be moved one position up;
  • After that, you need to sharply pull the starter rope again;
  • Then you need to quickly press the throttle lever and release it. This will automatically move the flap adjustment lever to its operating position. The engine speed will drop, which will indicate the readiness of the chainsaw for further work.

To start the tool hot, you will need to move the throttle control lever to the middle position and rarely pull on the starter cable.

Stihl chainsaw won’t start

The lightweight, convenient and compact Stihl chainsaw is often purchased for household work. Sometimes the owners are upset that the tool does not start: the engine turns on and suddenly stalls. In this article we will consider several reasons for such a malfunction, when the Stihl chainsaw does not start well or does not start at all.

The first thing that needs to be done in this case is to check the condition of the filter, the functionality of the fuel pump and carburetor, the external condition of the spark plug. perhaps there is no spark on the chainsaw. The same preventive work can be attributed to the assessment of the performance of pistons, cylinders, mufflers, crankshaft bearings.

After preliminary diagnostics, you need to try again to start the chainsaw, and contact a specialist if the problem is not resolved. One of the factors in the malfunction of the Stihl chainsaw may be insufficient lubrication of units and structural parts that rub during operation.

The main causes of chainsaw breakdown

Although all possible breakdowns in some specific parts of the chainsaw system have been described, their solution may not be enough. It is necessary to dwell on some aspects of problem solving in more detail.

Checking the breather and cleaning it.

The breather is another element, from the improper operation of which the chainsaw may not start or stall during the sawing process. This element is located on the fuel tank cap in the area of ​​the air hole. This is a kind of valve that does not allow gasoline to flow out and equalizes the air pressure required for the free flow of fuel into the carburetor.

If the breather is dirty, the working chainsaw stalls, and when it starts, it refuses to start. The thing is that air stops flowing through the hole. As a result, a negative pressure (vacuum) is created inside the fuel tank, which prevents the flow of gasoline to the carburetor.

Defining the problem is pretty straightforward. Disconnect the fuel hose from the carburetor and see what happens to the gasoline. If it flows freely in a good trickle, then everything is in order with the breather. If it is absent or it flows weakly and intermittently, then the reason is identified. the breather is clogged with dirt. You can solve the problem by cleaning the air hole with a regular needle or a powerful jet of compressed air.

Checking the condition of the fuel and air filters.

If everything is in order with the fuel quality, the chainsaw engine may not start due to clogged fuel and air filters. To diagnose these elements, it will be necessary to perform a number of manipulations associated with their dismantling.

For the fuel filter:

  • Disconnect the gasoline supply channel from the carburetor;
  • Pump up fuel.

If there is little or no pressure in the branch pipe, disconnect the filter. Before this, free the tank from the mixture and remove the filter element itself. Dismantling is done with a wire hook. A clogged replacement cartridge that causes a poor starting of the chainsaw engine can be cleaned, but it is best to replace it with a new one. When using the tool in dusty conditions, it should be cleaned on a regular basis.

A clogged air filter can cause the chainsaw engine to run erratically, making it stalling or difficult to start. Dust and dirt deposited on the adsorbent material impede the flow of air into the system, make the fuel mixture so rich that it will sometimes be difficult to start the tool.

Checking the air filter is one of the first steps in finding the cause of a poor start.

Care should be taken when removing the air filter, as dust accumulated on the surface of the saw during operation can enter the carburetor. And this is fraught with more expensive repairs. After detaching the cartridge, thoroughly clean it of accumulated dirt and rinse it with the addition of detergent. Dry the element and put it back in place just as carefully.

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Why the chainsaw starts and stalls

If the saw does start, but stalls at the first attempts to do the job, the reason may be different. The reason is chain jam due to lack of lubrication or problems with the chain brake, which makes further work impossible. In this case, check the oil level in the container. If everything is in order, the reason may lie in the tube leading the fluid to the lubricating mechanism. It can get clogged, break, stopping the movement of oil, or burst, causing the oil to flow out without reaching its destination.
The reason is problems with the carburetor. Parts of it may have deteriorated and require cleaning or adjustment. It is quite difficult to determine the breakdown in this case. Cleaning the carburetor is a rather difficult and monotonous task that not everyone can do. The same applies to checking the condition of its parts. It is better to entrust such an operation to professionals. The only thing you can do at home (but only for some models) is to customize it. All instructions on how to do this are in the accompanying documentation.

Chainsaw carburetor

The last reason is trivial. the low level of the fuel mixture in the tank. It manifests itself when the chainsaw stalls when tilted. The mystery lies in the fact that when the fuel runs out when tilted, it accumulates in a certain part of the tank. When tilted, the suction tube may end up in the airy part, which stops fuel flow into the chamber.

Chainsaw does not work, does not start, stalls

In this article, we will analyze the most common signs of chainsaw malfunctions.
The chainsaw has a simple design. Therefore, it is often easy to understand what exactly the malfunction of a chainsaw is.

If the cause of the chainsaw breakdown is found out, you can make a decision: repair the chainsaw yourself or contact a service center for the repair of chainsaws or a workshop.

Chainsaw malfunction signs:

  • the chainsaw will not start;
  • the engine is unstable;
  • the engine overheats quickly;
  • the engine starts, but quickly stalls;
  • the engine smokes a lot,
  • the chainsaw does not give out full power;
  • significant increase in fuel consumption;
  • oil or fuel leakage;
  • the chainsaw does not work, does not cut.

When you need to suspect that the chainsaw engine has broken down:

  • the chainsaw will not start;
  • the chainsaw starts, but the engine stalls quickly;
  • engine starts but does not pick up speed.


The situation when a malfunction makes itself felt, and the saw stops working, often puts the owner in a difficult position. In an amicable way, the unit must be sent for repair in order to find out exactly why it does not start, and then entrust the repair to professionals. However, not all breakdowns are fatal, and even a person who is far from technology can cope with them.

The first thing to do is diagnose the device. It consists in a careful examination of the main parts of the saw, namely:

  • Checking the fuel supply system;
  • Filtration system status;
  • Spark on the spark plug.

What are the breakdowns in the chain lubrication system:

  • No or little oil intake
  • Oil leaks

In the first case, we first examine the channels through which the oil is supplied to the tire and clean them. Driving them is quite common.

If there is a significant leak of oil (a slight leak of oil is normal for all gasoline saws), check the tightness of the pipes and fittings of the oil pump. The tubing may fall off and even crack. The violation of the tightness of the pipes is eliminated by replacing them or sealing them with a sealing material.

As for oil pumps, different models of chainsaws can have different designs, and the drive is also carried out in different ways (as a rule, the drive is carried out by a drive sprocket or a special gear on the crankshaft). If there is a problem with the oil pump, then most often you do not have to completely replace this entire unit, it will be enough to replace its moving part (plunger), it is it that most often fails due to the ingress of a large amount of dirt and sawdust.

The most serious damage is a crack in the oil pump housing. In this case, you will have to completely replace it.

We adjust the maximum number of revolutions

As mentioned earlier, the maximum RPM is set with the H screw, the RPM increases when it is turned clockwise, decreases when it is turned counterclockwise.

The highest speed of rotation of engines of gasoline chainsaws is in the range of 11,500. 15,000 rpm, depending on the model. Higher speeds are dangerous for the engine and will prevent it from starting. Maximum rpm can be determined by misfiring. If any, turn the screw H counterclockwise.

What to do if the chainsaw won’t start further?

If the initial inspection did not give anything or the defects were eliminated during the search, and the chainsaw does not start further, then you need to look for more serious reasons. It is best to identify and eliminate such breakdowns in a service center. However, with experience, you can find and eliminate them yourself. What to diagnose and check?

  • Compression in the cylinder;
  • Compression in the crankcase;
  • Carburetor operation.

In the first case, checking the compression in the cylinder will allow you to find out the state of the cylinder-piston group (CPG) of a chainsaw that does not want to start cold. For this you need a compressometer. The device is screwed into place of the spark plug and the engine is idle. Measurement of readings allows you to judge the state of the CPG. In the absence of a compression gauge, the compression in the cylinder can be determined offhand as follows:

  • Place your finger on the candle hole;
  • Try to start the chainsaw engine.

By placing your finger on the spark plug hole and pulling the starter, you can check the compression in the cylinder.

Top Reasons Chainsaw Starts, Then Stalls — Chainsaw Troubleshooting

If you feel that your finger is pulling strongly into the candle channel, then everything is in order with the compression. The absence of a vacuum in the chamber indicates a malfunction. The cylinder-piston group needs a more detailed inspection, which will give an idea of ​​the condition of the piston and cylinder, piston rings and bearings.

The chainsaw may not start on a cold one due to the lack of compression in the engine crankcase. The main reason for this is damage to the gasket placed between the cylinder and the crankcase. It is quite easy to detect the lack of compression:

  • Disconnect the upper tube from the carburetor;
  • Pour gasoline into an ordinary cork;
  • We immerse the removed tube in the fuel;
  • We pull the starter several times.

If the fuel is sucked from the cap when starting the chainsaw starter, then everything is in order with the compression. If not, see the gasket.

If the fuel is drawn in, then everything is in order. the gasket is intact. Otherwise, you will have to purchase a repair kit and replace it. How to do this watch the video why the Chinese chainsaw does not start:

Starting the tool can be complicated by improper operation of the carburetor or its breakage. It often happens that during the sawing process, the fastening screws are loosened and air is sucked into the cylinder. Check that the carburetor is securely fastened. Inspect it for fuel leaks. There can be a lot of reasons for the malfunction. It is possible to pinpoint the malfunction, eliminate it and fine-tune the carburetor only in a service center.

After going through the step-by-step troubleshooting of the chainsaw engine, you can find the malfunction, fix it yourself and successfully start your working tool. Do not take on jobs that you are not sure about. Entrust the troubleshooting to specialists from the service center.

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The main reasons why the chainsaw does not start or stalls and how to fix them

Owners of chainsaws sometimes have to deal with the fact that the saw, for no apparent reason, stops working normally. To figure out why the chainsaw stalls under various operating modes, and also to describe how you can diagnose a malfunction, we will try in our article.

Malfunctions leading to improper operation of the chainsaw

There are a number of faults that must be taken into account when diagnosing, since they can lead to interruptions in the operation of the saw.

  • Worn crankshaft bearings. With worn out crankshaft bearings, runout is inevitable on the main shaft, where the flywheel is attached. In such a situation, it is impossible to adjust the gap between the flywheel and the ignition coil, which entails interruptions in sparking, and unstable operation of the chainsaw.
  • Impulse channel contamination. The impulse channel serves to ensure the operation of the fuel pump, respectively, its contamination leads to improper operation of the pump, which will make it impossible for the saw to work (it will start and immediately stall).
  • CPG wear. As a rule, with increased wear of the CPG, there is a decrease in compression in the engine of the chainsaw, which will necessarily affect its ability to develop speed.
  • Dirty fuel and air filters.

Final carburetor setting

First, warm up the engine for 5-10 minutes (not at high speeds).

The reasons why the chainsaw starts and stalls

A chainsaw has long been not a luxury, but a necessary tool for those who have a summer cottage or home ownership. But, like any other technique, this tool tends to fail, despite the simple device.

The classification of the main faults includes:

  • complete absence of engine plant
  • the engine starts and stalls
  • unstable tool performance
  • work stop under load
  • loss of power.

If the chainsaw does not start at all, the reason may be:

  • Manufacturing defect
  • Lack of fuel
  • Problems with starting the ignition system
  • No spark from spark plugs
  • Poor fuel mixture
  • Carburetor clogged
  • High voltage wire problems
  • No compression.

Why does the chainsaw start and stall, what to do in this case? It is necessary to consider in detail the reasons for this.

Why the chainsaw does not start well and stalls

In case of poor start-up of the equipment “to cold”, the problem may be in the absence of compression, i.e. rings are worn out due to a long service life, they need to be replaced. Sometimes the reason that the engine does not start well in an unheated state is a problem with the muffler, as well as poor contact between the spark plug and the wire.

Also, the reasons for a poor start can be wear or damage to the gasket, rubber cuff in the accelerator pump of the carburetor, which causes additional air flow, leading to an increase in saw speed.

The chainsaw starts and stalls: reason, video

  • The most commonplace reason why the chainsaw started and stalled may be the low fuel level in the tank. This can be confirmed by stopping the operation of the tool when tilting, when the remaining fuel accumulates in a certain place in the fuel tank. With low-quality fuel, there may also be a problem with the operation of the chainsaw, in which case you need to completely replace it.
  • Breather blockage, which significantly reduces fuel consumption to the engine.
  • Insufficient contact of the wire cap with the plug, which leads to strong heating of the plug insulator. Contact deterioration can occur due to mechanical shear or carbon deposits.
  • Broken spark plugs.
  • Clogged muffler, which impairs exhaust gas output, causing the engine to stop running. For this reason, the chainsaw can start and stall at idle speed. Sediment in the muffler can also appear due to poor-quality fuel or improper use of the tool.
  • Poor carburetor adjustment.
  • Breakage of the piston group
  • Fuel filter or pump problems. In this case, gasoline may flow through the pump or poorly flow through the fuel filter to the carburetor. As a result, the chainsaw starts up and stalls when the speed increases.
  • Dirty air filter. Problems with this piece of equipment lead to the fact that, with increased loads on the engine, it simply cannot cope with them due to blockage and stops. A similar result is also obtained with an increase in revolutions.
  • Short circuit due to lack of or insufficient lubrication, or a problem with the chain brake.


The operation of the equipment must be correct, with periodic inspection of the constituent elements to prevent damage. To troubleshoot, it is necessary to check all components of the equipment for their functioning.

If the chainsaw starts and stalls, the cause can be eliminated on your own. If it is a shortage or improperly prepared fuel mixture, it must be corrected. For prophylaxis during the idle time of the chainsaw, you should always drain the remaining fuel.

Spark plugs should be checked periodically. In this case, remove carbon deposits that clog the joint gap, and also check the tips for the presence of fuel. Another cause of spark plug problems can be when they get wet with gasoline. To do this, they need to be removed, wiped off with a rag and left to dry. Defective spark plugs are replaced.

If there is no spark between the spark plug and the high-voltage wire, but if they are well connected, the ignition unit must be replaced.

A clogged muffler is a common cause of breakdown, in which a chainsaw starts up and stalls immediately. To eliminate the malfunction, you need to dismantle the muffler, clean it from carbon deposits with sandpaper or a special chemical solution. If the model of the chainsaw is non-separable, chemicals are poured into the system and are there for several hours, then it is blown.

The carburetor must be adjusted if the chainsaw stalls at idle speed. Fine tuning is a rather laborious process, so it is usually done in service centers. But, on some models there are elements for adjusting it, it is enough to turn the bolt half a turn to increase the speed of the chainsaw, the problems will be eliminated. If the jets, nozzles, channels and filters are clogged, the entire carburetor must be disassembled and cleaned. When the oil seals, gaskets, cuffs are worn out, it is necessary to replace them, preventing the “suction” of air.

If there is a problem with the fuel or air filter, it is necessary to replace the fuel pump or clean the air filter.

If the breather is clogged, it is necessary to clean it with a regular needle.

When the chainsaw starts up and immediately stalls, the reason may lie in the malfunctioning of the chain. To troubleshoot problems, check the presence of oil in the chain lubrication container, as well as the oil return pipe for breaks or blockages.

When inspecting the piston group, you should pay attention to the cylinder, if necessary, replace it or the piston. The cylinder can be bored to fit the new piston. If the piston with the cylinder is normal, you should pay attention to the defects of the piston rings and the need to replace them.

Among other things, you should control the service life of the parts specified in the product passport, which include the drive sprocket, tire, chain, part of the anti-vibration system, and replace them in time.

If the tool is idle for a long time, it is worth checking the condition of the fuel line. If the tube is cracked, you will have to replace it with a new one.