Chinese chain saw cuts out when you press the gas

Frequent malfunctions of the Husqvarna 236-240 chain saw

If the engine cannot be started, take the following steps in sequence:

Air filter and spark plug location.

  • Check that there is gasoline in the tank.
  • To change the fuel if it has been stored for more than a month.
  • Check the fuel filter. Disconnect the hose from the carburetor and watch the trickle come out. If gasoline flows freely, the fuel filter is not clogged. If it is not flowing fast enough, check the fuel filler cap or air filter.
  • Clean the air filter. The air filter can be removed for a test run.
  • Check and clean the muffler for carbon buildup.
  • Check the operation of the starting device. Repair the starter, if necessary (replace the pulley, spring or rope).
  • Remove and clean clogged carburetor.
  • Use a tester to check the high-voltage wire for a breakage.
  • Measure the gap between the flywheel magnets and the ignition module (should be 0.2 mm).
  • Unscrew the spark plug and inspect it. Measure the gap between the electrodes with a feeler gauge (0.5-0.6 mm is normal). By the appearance of the electrodes determine the nature of the fault. If the spark plug is dry, there is no working mixture. Filled with gasoline working part indicates poor-quality adjustment of the carburetor or lack of spark. To check for spark, connect the high voltage tip to the spark plug, place the skirt on the cylinder radiator and pull the starter cord. If there is no discharge between the electrodes, replace the spark plug. Carbon buildup on the electrodes indicates poor fuel mixture quality. Clean the center and side electrodes with sandpaper.
  • No compression. The reason. the failure of the piston group. Measure compression. First unscrew the spark plug. Then put a pressure gauge in the cylinder bore and use the starter cord to move the piston. The cylinder pressure indicates the condition of the cylinder-piston group (CPG). Engine must be at least 8 atm. Low ratings are caused by cylinder, piston, and piston ring wear.

The principal causes of malfunctions and remedies

The heart of any chainsaw is its engine

Every engine, no matter what brand (Partner, Husqvarna, STIHL), has an operating life of its own. The limit of this service life depends on the quality of use and storage conditions

It is important to be aware of the weaknesses in the fuel and oil you use. After expiry of moto-limit or after intensive work with chain saw, unpleasant consequences occur when chain saw

  • Does not start.
  • Starts up, but stops immediately.
  • Runs, but has intermittent engine operation.
  • Engine does not develop full power, stalls on throttle.

The consequences are quite varied, as well as the causes:

  • problems with fuel and oil, their ratio is broken or other brands of fuel and oil have been selected that have not been recommended by the manufacturer;
  • the fuel system is clogged;
  • Problems with the ignition system;
  • carburetor settings have been disrupted;
  • vibration has loosened the fasteners of engine components.

Each problem can be either independent or complex. Sometimes these problems can overlap. It is necessary to consider them in more detail.

Does not start the chainsaw

The need to carry out work. Not starting the chainsaw, what causes and remedies exist? Modern saws have the same working principle and design. So let’s take a look at an example: What are the usual causes of a STIHL 180 that won’t start??

Check spark plug condition. The spark does not flow due to fouling or improper gap between the diodes. That way the mixture doesn’t detonate. Clean the soot, adjust the gap, check the spark. To do this, put the tip with the wire on the spark plug, put it on the cylinder (or any other metal surface), yank the starter. If the spark is there, screw in the spark plug and start the engine. Along with manipulations with the spark plug, it is necessary to clean and wash the air filter.

If it doesn’t start you need to adjust the carburetor. Carry out the adjustment procedure as described in the instruction manual for your chain saw. These actions are usually enough to start the engine. These recommendations are also valid for other STIHL models (ms142, 240, 250, 350) and even non-STIHL models.

The saw starts and stops

Usually the reason why a chain saw starts and shuts down is the bad quality of the fuel and a mixture that is not making a proper combustion. Other possible causes, such as: clogged fuel system, improper adjustment of the carburetor.

If the fuel filters are clean and the quality of gasoline is good, it usually helps to simply add a turn of the “L” screw, which is responsible for the idle speed.

Chainsaw stalls on load

The engine is running and is quite stable at idle speed, but the chainsaw stalls when you step on the gas. Reasons in that case: clogged air filter, clogged fuel duct, poor fuel mixture quality, improper carburettor adjustment, problems with ignition system.

It is necessary to drain the content of the fuel tank and fill in good fuel, with the correct ratio of petrol and oil. Check fuel hose, check continuity, flush tank and hose if necessary. Carry out an additional adjustment of the carburetor.

The problems that arise are easy enough to fix with your own hands. Not expensive, just a periodic preventive cleaning of the chainsaw. Use good fuel and oil that is approved by the engine manufacturer. Mixing fuel with oil is recommended to do just before working with the chainsaw.

It is not necessary to keep the mixture ready, because resinous fractions are formed. These compounds negatively affect the piston group. At the beginning of the work let the chainsaw warm up a little and gradually put it under load. Following the rules of technology will keep your chainsaw in good working order for a long time.

Why the chainsaw keeps going off

The prerequisites, why the chainsaw starts and stops

For a long time chainsaw is not a luxury, but an indispensable tool for those who have a summer cottage or home ownership. But, like no other equipment, this tool tends to malfunction in spite of its uncomplicated construction.

Systematize the main faults:

  • Complete lack of engine start
  • The engine starts and stops
  • Unbalanced operation of the tool
  • stopping on load
  • Loss of power.

If the chainsaw does not start at all, the cause may be in the following:

  • Production fault
  • Lack of fuel
  • Problems with starting the ignition system
  • No spark from the spark plugs
  • Bad fuel mixture
  • Clogged carburetor
  • Problems with the high-voltage wire
  • No compression.

Why the chainsaw starts and stops, what to do in such a case? We must carefully examine the prerequisites for this.

chain, cuts, press

Chainsaw starts and stops: cause, video

The reason that the chainsaw can stall immediately after starting is due to problems with a certain piece of equipment.

  • The most obvious reason why a chainsaw starts and stops, may be a low fuel level in the tank. Proof of this can be seen by stopping the tool when it is tilted, when fuel residue accumulates in a certain area of the fuel tank. If the fuel is bad, it may also cause malfunctioning of the chain saw, in which case it should be changed.
  • Clogging of the breather, which significantly reduces the flow of fuel to the engine.
  • Lack of contact between the spark plug wire cap and the spark plug, which causes the spark plug insulator to become very hot. Deterioration of contact may be caused by mechanical displacement or sooting.
  • Problem of spark plugs.
  • Muffler clogging, which aggravates exhaust emission, resulting in engine stoppage. This can cause the chain saw to idle and cut off. Deposits in the muffler can also be caused by bad fuel or improper operation.
  • Poor carburetor adjustment.
  • Broken piston group
  • Problems with the fuel filter or pump. With all this, gasoline can leak through the pump or poorly flow through the fuel filter to the carburetor. Eventually, the chainsaw starts and shuts down when the rpm increases.
  • The air filter is dirty. The problems with this element of the equipment lead to the fact that, when the engine is overloaded, it simply can not cope with them because of clogging and stops. A similar result also comes out with increasing speed.
  • The chain is shorted due to lack or insufficient lubrication, as well as problems with the chain brake.

Why the chain saw does not start and stops

With poor start of the equipment “in the cold” mismatch can be in the lack of compression, t.е. Wrong riding surface, rings are worn because they have been in use for too long, they must be replaced. Occasionally, the reason that the engine does not start well when not heated, is a problem with the muffler, and poor contact between the spark plug and the wire.

Another reason for a bad start can be a worn or damaged gasket, rubber seals in the booster pump of the carburetor, which causes additional air flow, resulting in an increase in the speed of the saw.


The equipment should be operated properly, with repeated inspection of the component parts to prevent breakdowns. To clear up problems, you need to check all components of the equipment for their function.

If the chainsaw starts and stops, the cause can be corrected by your own efforts. If it is a shortage or an incorrectly prepared fuel consistency, you need to correct it. For preventive care, always drain off any remaining fuel when the chainsaw is not in use.

READ Which chainsaw is better for making firewood?

Check the spark plugs repeatedly. Clean up any carbon deposits that might clog the joints and inspect the nozzles for fuel. Another cause of problems with spark plugs can be their wet gasoline. To do this, take them off, wipe with a rag and leave to dry. Defective spark plugs must be replaced.

If there is no spark between the spark plug and the ignition wire, but in the presence of their not bad connection, you need to change the ignition unit.

Muffler clogging is not uncommon cause of failure, when the chainsaw starts and stops immediately. To fix the problem it is necessary to dismantle the muffler, clean it from carbon deposits with sandpaper or a special chemical solution. If the chainsaw model is non-disassembled, chemicals are poured into the system and stay there for several hours, then it is blown out.

The carburetor needs to be adjusted if the chainsaw stalls at idle. Clear tuning is quite a labor-intensive process, so it is usually done in the service centers. But, on some models there are elements for its option, rather turn the bolt half a turn to increase gasoline saw speed, the problems will be solved. If the jets, nozzles, channels and filters are clogged, you need to disassemble and clean the whole carburetor. If the seals, gaskets, collars are worn, you need to change them, preventing “sucking” air.

READ What Oil Can I Use to Dilute Gasoline for a Chainsaw

If you have a problem with the fuel or air filter, change the fuel pump or clean the air filter.

If the breather plug is clogged clean it with an ordinary needle.

If your chain saw starts and stops right away, the chain may be malfunctioning. For troubleshooting, check oil presence in chain lubrication reservoir and oil drain tube for rupture or blockage.

Checking spark plugs and ignition system

The manufacturer recommends that the spark plug be changed annually, regardless of how often the tool is used. Failure to follow these tips leads to quite predictable results: malfunction at idle speed, subsequent failure.

Typical ignition system defects are as follows:

  • the spark plug is flooded with fuel at the start. It is necessary to remove it from the socket, dry it, if possible blow it out with compressed air. Drain the residual fuel from the cylinder through the installation hole, blow out with compressed air. Then install the spark plug, reconnect the ignition cable, start the engine.
  • No spark on the spark plug electrodes. Disconnect the high-voltage wire and check the spark. If the spark is normal, check the connection and eliminate the defects found. Lack of spark on the high-voltage wire indicates ignition unit malfunction. This unit is beyond repair and must be replaced by a new one.
  • The gap between the electrodes of the spark plug is broken. This parameter may be between 0.2 and 0.5 mm for different types of devices. Check and correct with a feeler gauge or caliper. Check to see the correct value from the tool’s instruction manual.
  • By the appearance of the candle, you can determine the direction of the search. If the spark plug is dry after several attempts to start the engine, it means that there is no gasoline in the cylinder. The fuel system and carburetor should be checked.
  • The presence of soot or black carbon deposits on the electrodes indicates improper carburetor adjustment or clogging of the air filter. Possibly low-quality fuel with too much oil is being used. When the ignition system is working properly, the electrodes are uniformly gray and brown on the insulators.

Chainsaw Stops at Idle

What to do if the chain saw cuts out at idle speed

Chainsaw stalls at idle rpm: this is the problem faced by many owners of this tool. The chainsaw is quite light by design. But there are times when it fails. The main problem in troubleshooting is finding the right reason for the malfunction. Once the cause is established, fixing the defect is usually quite simple.

Probable causes of failure

The power unit of all chainsaws is a single-cylinder internal combustion engine. For devices of this type are characterized by such malfunctions as a violation of intra-cylinder compression, changes in the ratio of the fuel mixture, incorrect ignition operation, poor-quality fuel and lubricants. The main problems with the power unit are as follows:

  • the engine runs steadily at minimum rpm, but stalls when the rpm is increased;
  • start-up is normal, but idle speed is unstable, quickly stalls;
  • fails to start.

Chainsaw electronic ignition diagram.

Abnormal operation at idle can be caused by a variety of reasons. They can be divided into several positions:

  • capacity of the filters (gasoline and air) has been reduced;
  • abnormal operation of the ignition system:
  • carburetor settings are changed spontaneously;
  • Faulty elements of the gasoline line;
  • Clogged exhaust ducts, muffler;
  • piston, cylinder, valve defects.

Repair should begin with an external inspection and check the presence of fuel in the tank.

chain, cuts, press

Check and Repair Filters

The engine may run intermittently or stall if there is not enough fuel or air. Reasons. clogged air or fuel filter. To check the fuel filter, remove the fuel line hose from the carburetor nozzle and place it in a container. Then press the fuel primer several times. If fuel is pumping normally, in distinct doses, without dirt then the fuel filter is defective. If the jet is weak or the fuel is not pumping at all. the filter should be replaced or if possible cleaned.

READ Chain Whirring While Starting Chainsaw

Sawdust clogging the fuel filter is one of the things that can cause chain saw malfunctions.

The device must be removed from the fuel tank (having previously drained all the fuel from it). The fuel filter on most models can be pulled out through the neck with a wire hook. If filter is collapsible and can be cleaned, take it apart and wash it according to the manufacturer’s recommendations. Otherwise replace with a new filter.

Similar problems can occur if the air filter is clogged with dust, sawdust, dirt. If you don’t have enough air in the filter, the fuel mix will be too rich and won’t burn properly.

The filter should be removed for checking. When working, you need to take precautions so that the dust does not get into the carburetor. The unit should be cleaned and washed in warm water with detergent. If possible blow it off with compressed air at a low pressure after it dries and install it again. If it works correctly the problem is solved, if not. keep looking.

If you use your power tool regularly, it’s a good idea to replace the fuel and air system filters every three months.

What to do if the chainsaw doesn’t hold idle speed??

in this video you will learn what happens when the chain saw

Does not work at low engine speed and will not start.

Chainsaw starts and stops

does not work stalls. Doesn’t saw. How much can we talk about the secret here.

Checking the spark plug and the ignition system

According to the recommendations of the manufacturers, the spark plug should be changed annually, regardless of the intensity of operation of the instrument. Failure to follow these tips leads to a completely natural result: failures at idle speed, the subsequent failure of the.

Typical ignition system faults are as follows:

  • The spark plug got covered with fuel at startup. It is necessary to remove it from its seat, dry it, blow it out with compressed air if possible. Drain residual fuel from the cylinder through the adjustment hole, blow out with compressed air. Then install the spark plug, connect the high-voltage wire, start the.
  • No spark on the spark plug electrodes. Disconnect the high voltage cable and check for a spark. If the spark is normal, check the connection, fix the detected defects. Lack of spark on the ignition cable is indicative of an ignition unit malfunction. This unit is beyond repair, need to be replaced with a new one.
  • The gap between the electrodes of the spark plug is disturbed. This parameter for different types of devices can be in the range of 0.2 to 0.5 mm. Check and correct with special dipstick or caliper. The necessary value can be found in the instruction manual of the tool.
  • The appearance of the spark plug can determine the direction of the search. If the spark plug is dry after several attempts to start the engine, it means that there is no petrol in the cylinder. It is necessary to check the fuel system and the carburetor.
  • Black soot or carbon deposits on the electrodes indicate improper carburetor adjustment or a clogged air filter. You may be using low-quality fuel with a lot of oil. When the ignition system is working properly, the electrodes have an even gray color and brown deposits on the insulators.

READ Goodluck chainsaw carburetor tune-up

Check and repair carburetor

If checking the ignition system, fuel filters, muffler did not give tangible results, the tool still does not want to work properly at minimum rpm, you need to check the carburetor.

To adjust the modes of operation on the body of the device are three screws to set the minimum speed, maximum speed and idle speed.

Problems “On Hot

If you notice that the chainsaw has no problem starting without warming up, and after warming up it stops. And it will not start until it cools down, then there may be several problems.

First, there may be a hose, packing or gasket leak somewhere. Second, inspect the muffler for fouling. The third reason is the cylinder piston group (CPG). isn’t there any scoring or irregularities?

Sometimes the carburetor needs adjustment. Another important cause of malfunction, is the ignition coil. In cases when it fails the spark is lost or becomes very weak, which is not enough to ignite the fuel mixture.

There are known cases when the master tries the engine hard, then on cold, then on hot, thereby pumping fuel. Here you need to take hold of yourself, move the choke to “hot start” and gradually start the tool. At the same time we bring down the revolutions to almost idle level and for 40-45 seconds it warms up.

Why the chainsaw stalls, the main causes

The main causes of chainsaw malfunctions

Although the chainsaw is a simple device, from time to time its work has some problems that can only be solved by disassembly. The following malfunctions are examples:

  • Your chain saw is not picking up speed;
  • Your chain saw stops cutting;
  • chain saw starts and stops;
  • The chainsaw is losing its power;
  • Your chain saw stops when you press the button.

Most often the problems are caused by the malfunctioning of the engine or by malfunctioning of other systems and components. Proper handling of the machine is important. If you follow all the rules of thumb, you are likely to have problems with the most obvious problems. When searching for the cause of a problem it is advisable to begin with checking the simplest part of the chainsaw and end with the most complex one.

Checking the chainsaw’s major systems

If your chainsaw refuses to operate normally, you must make sure that all the conditions required for its normal operation are met:

Then it is necessary to check all of its elements one after another. First you need to check the fuel tank. If the cause is not the volume or quality of the fuel, the likely cause of the malfunction could be the spark plugs. The play on the spark plug must not exceed 0.5 mm. If it is too low, it means that there is too much carbon on the plugs. In that case you should remove the spark plugs, clean them, put them back and try to start the chain saw. It is also a good idea to change the spark plugs completely from time to time, even if they are in good condition.

Then check the condition of the fuel filter and carburetor. Cleaning the fuel filter yourself is an easy task, but the carburetor repair is best left to professionals.

The chainsaw starts and stops. the cause

If the chain saw does not start and stops when you first try to use it, it may be because the chain brake is having problems or the chain is seized by lack of lubrication. In this case, measure the oil level. If the amount of lubrication is sufficient, the cause may be in the tube that leads it to the lubricator.

Another reason could be a carburetor malfunction. If it only needs adjustment, you can carry out the adjustment yourself according to the manual. If your carburettor needs cleaning or repairing, you need professional help.

Low fuel level in the fuel tank is another possible cause. If it has a low fuel level, the fuel tank is located on the opposite side of the suction pipe.

Why does the chainsaw quit while heating up?

It is not uncommon for a chainsaw to start when cold, but to cut off as it heats up. This behavior of the tool can be caused by the following reasons:

  • The carburetor is not properly set. You can diagnose this problem by starting the device when it is cold. If it is made without closing the air damper, and the motor starts without a pre-flash, it means that after the motor is warmed up, the fuel is pouring into the spark plug. The solution to this problem is to adjust the carburetor. on carburetor adjustment
  • Coil (ignition module) malfunction. You can diagnose this problem by testing the spark first on a cold motor and then on a hot motor in sequence. If there is no spark after a hot engine, the ignition coil must be replaced.
  • Spark plug failure. In this situation, as with ignition module failure, the spark disappears when the motor heats up. It is necessary to replace the spark plug with a new one, and if this does not solve the problem, the ignition module and the distance between it and the flywheel should be checked.

Why a chain saw cuts out under load

Sometimes the chain saw is unable to operate normally when under load. Most often caused by improperly adjusted or leaking carburettor. This problem can also be caused by air leaks through the carburetor gasket or crankshaft oil seals. The tool, unable to function under load, also cannot confidently hold idle speed.

Diagnostics begins with checking the carburetor and crankcase for leaks. If you find air leaking through the crankshaft oil seals you need to replace them. If you find air leaking in the carburetor to solve the problem requires the installation of a repair set of gaskets.

If these actions have not led to the desired result and the carburetor and carburetor are sealed, it is necessary to adjust the carburetor.

If the Husqvarna chain saw cuts out under load, then with any deviations in the operation of the engine it is necessary first of all to check the impulse hose, because it is the most common cause of failure of this make of chain saws.

What to do if the chainsaw stalls when you step on the gas

One of the most common questions regarding the operation of this device: why does the chainsaw stall when you press the gas and what to do to solve the problem? In such a situation you should do the following actions:

  • check the fuel filter;
  • inspect the fuel hoses for leaks;
  • check the silencer;
  • try to increase the engine speed a little;
  • check the condition of the rubber seals on the crankshaft.

Why the chain saw doesn’t rev up and shuts down

If the saw can not pick up speed or cuts out when you press the gas, it is most likely due to leaky carburetor or motor crankcase. This can be corrected by checking and adjusting the carburetor for leaks.

This fault may also be due to a defective fuel tank breather. Because of the vacuum in the fuel tank when the chain saw is running, the correct volume of fuel mixture is not getting to the engine so it won’t start or will shut down. If you stop the chainsaw, open and close the fuel tank and turn it on again, it will run normally for about five minutes and then stop picking up again or stall.

Turn off on load

Heavy-duty chainsaws will often wobble from the load. You most likely have a clogged fuel filter and it needs to be replaced. If that doesn’t help, you need to check the quality of the fuel mixture and prepare a new.

Filters often get clogged, especially almost daily. The air filter can be disconnected and washed under a stream of warm water. Before installing in place. dry it thoroughly.

If no fluid comes out of the carburetor after disconnecting the fuel hose, it means it is clogged. It can be cleaned or replaced with a new one.

If the tool is frequently used, the gasoline pump may not work properly. In the end, every part has an expiration date. It should be replaced or contact service center.

The saw will stall after releasing the “throttle

Here you need to adjust the carburetor and check for a strong air suction.

We have already seen the most common chain saw faults. I hope your saw will be long-lived. But even rugged models like STIHL and Partner can sometimes go wrong.

Please do not rush off to the service center, first use my advice, this way you can avoid unnecessary costs.

If you found this article interesting. share it with your friends through social networks. And I bid you farewell. Good luck and see you on my blog!

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