Chainsaw does not start China reasons

Why does the chainsaw start and immediately stall

The chainsaw starts up and immediately stalls, the reason for this behavior may be hidden in the carburetor. A malfunctioning fuel pump or malfunctioning of the main fuel jet can cause this saw to behave like this. The inability to operate the chainsaw after starting, requires a full diagnosis at the service center.

All of the above options for engine malfunction have similar causes, which, depending on their neglect, can have different manifestations. For example, with a slight intake of air into the crankcase of the engine, its work will not change much, the engine power will drop slightly, its maximum speed will increase, and it will be able to heat up a little more. In the middle stages of air leakage, the engine will stop idling and will get very hot during operation. Strong air suction, will make it impossible for the saw to work, it will start and immediately stall.

In parallel with the visible manifestations of malfunctions, for example, the inoperability of the chainsaw after starting, processes will take place inside the engine at the time of its malfunctioning, which irreversibly lead the saw to the most serious consequences, for example, melting the piston, jamming the crankshaft.

The chainsaw starts and stalls cause

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

  • Why does a chainsaw stall when heated
  • Why does a chainsaw stall under load
  • Why the chainsaw doesn’t pick up speed and stalls
  • Algorithm for checking the crankcase for leaks
  • Why does the chainsaw start and immediately stall
  • Malfunctions leading to improper operation of the chainsaw
  • Summing up

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 idle speed. 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 is detected in the carburetor, the cause can be eliminated by installing a repair kit of gaskets.

chainsaw, does, start, reasons

Only after the above actions have not yielded results and the crankcase with the carburetor is sealed, you can start adjusting the carburetor.

The reason for this algorithm is as follows, if the air leak 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.

Why does a chainsaw stall when heated

The situation in which a chainsaw starts up cold, and in the process of heating it can stall, is familiar to many who deal with them. The main reasons for this behavior of the saw are as follows.

  • Defective ignition module (coil). Determine the malfunction by checking the spark first on a cold engine, and then on a hot one. If there is no spark on a hot engine, then it is worth trying to fix the malfunction by replacing the ignition coil.
  • The carburetor of the chainsaw has an incorrect setting (fills a hot candle). You can determine the problem by how the saw is started on a cold one. If for a cold start it is not required to close the air damper, and the engine starts without a preliminary flash, then the fuel mixture is formed incorrectly and after the engine warms up, the fuel fills the spark plug and makes it impossible to start. The problem is eliminated by adjusting the carburetor.
  • Spark plug defective. In such a situation, similar to a faulty ignition coil, the spark disappears when the engine heats up. It is worth trying to replace the spark plug with a new one, and if this does not help, then you need to check the ignition coil and the gap between it and the flywheel.

You can check the ignition coil using a multimeter or by replacing it with a known good one. The test with a multimeter of the primary and secondary windings is carried out in the resistance measurement mode. The resistance index of the primary winding, working coil, is 1 kOhm. secondary 4 kOhm.

Why the chainsaw doesn’t pick up speed and stalls

If the chainsaw is not able to pick up speed a minute after starting or stalls when the gas trigger is pressed, most likely the carburetor or crankcase is leaking. As in the previous case, the problem can be solved by checking for leaks and adjusting the carburetor.

If the chainsaw does not pick up speed and stalls after it has been running normally for about 5 minutes, the reason may be a defective fuel tank breather. The vacuum created in the fuel tank during tool operation prevents the engine from receiving the necessary amount of fuel for its normal operation, and for this reason it will be unable to gain speed or stall. At the same time, if you stop the tool, open and close the fuel tank cap and start the chainsaw again, the tool will work normally again for about five minutes, after which it will stop gaining speed or stall.

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The reason that the chainsaw does not pick up speed can also be excessive carbon deposits in the muffler, which makes it difficult to exhaust exhaust gases, thereby reducing the power and engine speed.

If you want to check the tightness of the crankcase, but there is no special tool, you can use the following test procedure.

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 the 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.

Algorithm for checking the crankcase for leaks

  • Remove the side cover and tire from the chainsaw.
  • Unscrew the spark plug and put a lace with knots into the cylinder through the spark plug hole, thereby stopping the movement of the piston and crankshaft.
  • As a lace with knots, you can use the old cord from the starter, tying knots on it every 3-5 cm.
  • Spin the chain saw drive sprocket.
  • Remove the oil pump cover and the pump itself.
  • Remove the starter from the chainsaw.
  • Unscrew and remove the flywheel.
  • Remove carburetor.
  • Using a syringe, through the carburetor hole in the cylinder, pour gasoline into the crankcase, while observing the crankshaft oil seals. If gasoline flows through them, then the oil seals have become unusable and must be replaced with new ones.
  • It is better to entrust the installation of oil seals to professionals.

An indirect sign of crankcase leaks are oil leaks in the area of ​​the oil seals.

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

Summing up

When the first signs of improper operation of the chainsaw appear, it is worthwhile to carry out a complete diagnosis. In order to avoid damage to the saw as a result of improper maintenance, it is better to entrust the work of identifying and eliminating engine malfunctions to professionals. And most importantly, you do not need to use a chainsaw with minor defects, since this will lead to even greater problems.

Chainsaw won’t start: top 3 main causes of breakdowns

Fuel problems

If the tool does not turn on well when cold, it may be caused by an unadjusted carburetor, dirty fuel filter and lines. If starting is difficult, it is imperative to complete the fuel system diagnostics completely.

Pay particular attention to the quality of the fuel used. If even a little water gets into the finished mixture, then it is considered unusable, as it loses its qualities. Another nuance that must be taken into account is the quality of the mixture, namely, its shelf life before use. Ideally, prepare as much of the mixture as you plan to use in a day of work. If you prepare a lot of the mixture and leave it unused for storage, then over time it will lose its qualities.

Features of return and warranty obligations

In order to carry out warranty service, you will need to present a completed warranty card.

Why the chainsaw stalls at idle?

If the saw stalls at idle, then you should pay attention to the carburetor adjustment. You can make repairs yourself using a special screwdriver. Another way to solve the problem is to disrupt the operation of the fuel pump due to air leaks into the crankcase.

Malfunctions in the engine

Among the main problems that arise with the motor, there are: sticking rings, air leaks, compression loss, CPG wear. Many owners have noticed that the instrument does not turn on when it is cold, but starts up without problems when it is hot. This malfunction occurs when the CPG is slightly worn, when the compression in the motor decreases. For a more accurate diagnosis, it is advisable to contact a specialized center.

Why the chainsaw doesn’t rev up and stalls?

If the saw does not develop power and does not increase the speed, then the carburetor or engine crankcase should be checked for leaks. It is also necessary to check the carburetor for leaks if the saw fails when the gas is pressed. Another nuance that needs to be checked is the fuel tank breather, which can also affect the fact that the saw does not develop speed.

Identifying and eliminating obvious chainsaw malfunctions.

To determine the reason why the chainsaw does not start or stalls when starting, it is necessary to troubleshoot the tool. The essence of the procedure is to consistently inspect the condition and operation of the main working elements of the saw motor. At this stage, we check:

  • Spark plug present;
  • Fuel supply;
  • Filter status;
  • The operation of the breather of the stalling unit built into the fuel cap;
  • Discharge duct function.

to the content

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

The first step in finding the reasons why the 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.

Checking the spark plug with an idle chainsaw

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.

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.

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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 done 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.

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 started, 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, preventing 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.

Determine the availability of fuel and its supply.

First you need to make sure that there is a fuel mixture in the tank of a chainsaw that does not want to start, and it regularly enters the carburetor. With a full tank, we check how the mixture is fed through the gas line. Disconnect the fuel system pipe from the carburetor and try to pump it up. In the case of a complete order, when pumping up, gasoline will be supplied in jerks in accordance with the norms set by the manufacturer. Poor or no fuel supply may result from:

  • The fuel supply channel is clogged;
  • Debris-clogged fuel filter.

Often the reason for a poor start of the chainsaw can be a tank that is too full. In this case, you should pay attention to the presence of smudges under the saw case cover. If present, see the connection of the gasoline feed pipe to the carburetor. Most often, it is squeezed out by pressure when the tank cap is screwed on, which is filled under the very neck, which prevents the engine from starting.

The quality of the fuel mixture can also be one of the reasons why the chainsaw does not start. If, after completing the work, the remaining gasoline is not drained, and the tool is left for long-term storage (more than 2 weeks), then the processes of resin formation and polymerization of the components will begin to occur inside the tank. What can cause carbon deposits on the piston, rings and cylinder liner. Therefore, always prepare the mixture only in the required amount before work.

Finding reasons why the chainsaw won’t start

Amateur and professional chainsaws are complex devices. The service life of their two-stroke engines, components and assemblies has its own limitations. For this reason, quite reliable and expensive tools, along with cheap Chinese units, periodically fail and refuse to start. The situation when the chainsaw does not start or stalls is not very pleasant and sometimes confuses the user. How to identify and correct a malfunction by returning the instrument to work.

  • Identifying and eliminating obvious chainsaw malfunctions.
  • Checking the spark on the spark plug and eliminating the causes.
  • Determine the availability of fuel and its supply.
  • Checking the condition of the fuel and air filters.
  • Checking the breather and cleaning it.
  • Chainsaw outlet check.
  • What to do if the chainsaw won’t start further?

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 pipe, disconnect the filter. Before that, 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 make it difficult for air to enter 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 from the 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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Chainsaw outlet check.

One of the reasons that a chainsaw does not start well may be a clogged exhaust channel or its muffler. At the same time, a drop in power is noted in the process of sawing sawn timber and logs. This is most often due to resinous deposits on the spark arrestor or muffler channel, which are formed during the combustion of a poor-quality mixture of gasoline and oil, which impede the removal of exhaust gases.

Resonator clogged with carbon deposits can cause poor starting of the gasoline saw.

Eliminate the reason for the poor start of the chainsaw, in this case, you can remove the accumulated combustion products. To do this, perform a number of manipulations:

  • Remove the muffler by unscrewing the screws;
  • Remove the cooling panel and gasket;
  • Remove the spark arrestor;
  • Disassemble the resonator housing;
  • Wash all elements from carbon deposits with a detergent;
  • Let them dry completely;
  • Collect everything in reverse order;

To prevent dust and sand from entering the cylinder when cleaning the muffler, cover the outlet of the chainsaw engine with a clean rag.

Wear of parts

Most often, the chain sprocket, chain tire, spark plug and piston rings fail. It is recommended to change them as the tool is used. If you are not doing service and the saw suddenly breaks down, replace the spark plug first. It becomes covered with carbon deposits, the electrode tip comes off the wire. A new plug can solve the problem of normal starting. The guide bar and sprocket are consumables, so they need to be replaced more often than candles. They guide the chain to determine the quality of the cut, and it is very dangerous to operate the saw with a worn bar. Replace these parts at a service center or buy similar and replace yourself.

Piston rings will fail when sawing hard materials and under significant continuous stress. Vibration breaks them, they become covered with cracks, the cylinders begin to sink. Wear is indicated by poor traction, low power, smoke draining from the muffler. Replacing is easy, the main thing is to remove the cylinder-piston group from the saw body and clean it from fuel traces so that the new rings lie on the clean pistons.

Cylinder-piston group

This is the last possible source of the problem and the most difficult to repair. First, check its serviceability. In place of the spark plug, screw the compression gauge and start the saw. If you do not have this device, simply close the candle hole with your finger and start the mechanism. If you feel a strong retraction, then everything is in order with the cylinder-piston group. If there is no compression, then you will have to conduct an external examination.

The slightest dents and chips will immobilize the cylinder. You can make it wider and put a new piston, or you can replace the entire group, then the tool will serve you longer after repair.

New chainsaw won’t start

When you buy a new tool, you count on its quality. Unfortunately, not every implement meets the job requirements.


A special oil-gasoline mixture is prepared by the owner of the tool manually, so inaccuracies are possible here. The desire to save on fuel has a bad effect on the tool, up to its complete inoperability. To keep everything working without interruption, make sure you are using the highest quality gasoline and oil that is indicated in the instructions. A properly formulated mixture can be stored ready-made for no longer than two weeks.

Gasoline fuel loses its properties in the third week and will not be able to power your instrument normally. Chinese-made chain saws are especially sensitive to the quality of the mixture. Sometimes you have to go through several different oils before you achieve a smooth and high-quality stroke.

Ignition system

Also known as the ignition unit, this element is responsible for the electrical generation of an incendiary spark. If the electrodes on the spark plug can be pulled closer together, the unit cannot be repaired. It is simply replaced with a new one. To check for a spark, remove the spark plug, replace the tip and run the saw with no load. If the spark does not skip even after the electrodes come close, contact the service center. There, your saw will be fitted with a new ignition system.

Filling the engine

Most often, this problem occurs when trying to start the engine “hot”. To resolve the issue, turn the air duct flap horizontally and try to wind the mechanism. It may not start immediately, but after evaporation of part of the fuel mixture, it should start working. Warm up the mechanism for fifteen to twenty seconds, and then put it on idle. Open throttle fully and allow engine to dry.

Why the chainsaw won’t start: causes and remedies

To facilitate physical labor, mankind has come up with working tools. They serve to influence objects and materials. There are mechanical tools and those that are powered by pneumatic, hydraulic, fuel energy or electricity. The tools are used in construction and for minor repair work in everyday life. One of the most popular tools is the chainsaw. It is a reliable tool that can be used to cut and shape solid objects and materials. But the chainsaw does not always work properly. This article will discuss the cases in which the new chainsaw refuses to work, the causes of this problem and how to fix it.

  • New chainsaw won’t start
  • Causes
  • Solutions
  • The chainsaw does not work: causes and remedies
  • Fuel
  • Spark plug
  • Filters
  • Muffler
  • Hoses and connections
  • Carburetor
  • Ignition system
  • Cylinder-piston group
  • Chainsaw mechanisms do not work: reasons and solutions
  • Insufficient chain lubrication
  • Fuel quality
  • Cleaning
  • Wear of parts
  • Filling the engine
  • Preventive measures
  • Spark plug

    This reason is easy to determine. If the spark plug is faulty, the device starts up and stops working immediately. The accumulation of the fuel mixture on the electrodes and the buildup of carbon deposits on them leads to a malfunction of this element. To get rid of this problem, remove this element, remove the carbon deposits with a file, turn it out and wait half an hour for it to dry. Drain the rest of the mixture, put the candle in place and you can continue working.

    If this element is dry, its malfunction lies in the large distance between the tip and the sparking wire. Check the spark: remove the tip, remove the candle, put the tip in place, place the candle so that it touches the cylinder with its skirt. Start up. If the spark is visible and large, the spark is not the problem. If the spark is weak, reduce the distance between the electrodes using a special feeler.