The trimmer stalls at maximum speed

Troubleshooting reasons and features

Why the chainsaw stalls after starting or during operation, you can find out only after performing a check. As a result of the check, you can not only find the reasons for the malfunctioning of the motor, but also possible breakdowns. To find the exact cause, you need to know in what cases the occurrence of a malfunction is observed. Let’s consider such cases, as well as find out the features of troubleshooting.

Immediately after wound up

The unit may stall immediately after starting if the carburetor is misaligned or incorrectly adjusted – this causes an uneven fuel supply. The result is that the device vibrates distinctly. For troubleshooting, the carburetor is reconfigured, following the instructions for the mechanism.

Also, the engine stops when the fuel supply valve becomes clogged. In such cases, it is sufficient to simply clean it. If the mower started working at first, but then immediately stalled, then it is possible that the fuel enters the carburetor unit with some difficulty. The weakening of the valve helps to solve the issue, which ensures free circulation of the mixture in the system..

The stoppage can also be caused by air leaks in the presence of mechanical damage to the hose (holes, cracks) that takes the fuel. In this case, add more revolutions to the drive in order to quickly expel air bubbles from the system..

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trimmer, stalls, maximum, speed

What could have broken

Problems with the lawn mower due to the fact that this device does not start are classified in a certain way by service specialists. They highlight faults with the following components of the mechanism:

  • an engine in which the piston and bearings may wear out or fail, crack the crankcase;
  • the fuel supply system, while the filter may be clogged or problems with the carburetor;
  • mechanical damage to wires, tubes, hoses;
  • ignition circuit.

To correctly determine the node where the breakdown occurred, you need to pay attention to the circumstances under which the trimmer stalls.

Stalls when tilted

The reason that the chainsaw starts to stall when tilted is the lack of flow of the fuel mixture into the system. The fuel pipe is located directly at the bottom of the gas tank, so tilting the tool causes the pipe to simply sit over the fuel mixture. Actually, therefore, during the operation of the tool, it can suddenly stall.

Stalls when you press the gas

If the engine stalls when gas is added, the following factors may be the reason for this:

  • clogged or incorrect carburetor setting;
  • contamination of the air filter, whereby the engine does not have enough air to set speed;
  • clogging of the fuel filter, which contributes to the intake of an insufficient amount of the fuel mixture;
  • malfunction of the cylinder-piston group. With an insufficient amount of oil in the fuel mixture, excessive friction of the piston against the cylinder walls occurs, which entails overheating and the formation of scoring.

In case of overheating with a lack of oil in the fuel mixture, the engine will need to be overhauled, which is one of the most unpleasant consequences. In order to properly adjust or clean the carburetor, you should give it to a specialist, as lack of experience with small parts can lead to damage to the mechanism. Do-it-yourself air and fuel filter check.

It is important to know! The fuel filter should be replaced every 3 months during daily use of the tool.

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If the chainsaw does not allow you to develop speed when you press the gas, then it is advisable to try to replace the fuel mixture in the tank, especially if it has been in the tool for a long time.

Why else can a chainsaw stall when you press the gas

If, after adjusting the carburetor of the chainsaw, the problem remains, then a number of other factors should be checked. There are enough of such factors, and their verification must be carried out sequentially, moving from the easier to the more complex. It is in this order that we will consider all the reasons why the chainsaw does not develop high revs, and at the same time stalls. It should be noted that in this case, the tool starts up and works properly at idle speed..

  • Check the chain tension – if the cutting element is tightened too much, this will put a heavy load on the engine. In this case, it will be difficult for a high-speed engine to turn the chain, as a result of which we get its termination of work. The problem can be corrected if the chain tension is correctly adjusted. The chain should rotate easily by hand, but keep in mind that at XX it should not move. If the chain moves at idle speed, then you need to adjust the upper screw XX
  • The quality of the fuel mixture and the correctness of its preparation. It is recommended to use AI-92 gasoline for the chainsaw. It is mixed with two-stroke oil in appropriate proportions. Although the mixing ratio is indicated on the label of the container with oil, it is necessary to use the data indicated by the tool manufacturer. The optimal value for the mixture of gasoline and oil is 40/1, that is, 25 ml of oil must be added to 1 liter of gasoline. The proportion means that for 40 liters of gasoline, you need to add 1 liter of oil. If you do not adhere to the manufacturer’s recommendations, then in the end this negatively affects the operation of the carburetor and the serviceability of the CPG
  • Silencer – very often sawfillers do not pay enough attention to the exhaust system of the tool. If the muffler is clogged, and this necessarily happens over time, this negatively affects the operation of the motor. Silencers on chainsaws are collapsible and non-collapsible. For non-separable devices, the connections are flared, so in case of clogging, you need to either replace the part, or flare for cleaning. A clogged muffler affects the operation of the tool, so do not wait until the chainsaw stops starting
  • Air leaks – parts and mechanisms of the chainsaw are connected to the cylinder through gaskets. As a result, such connections are sealed, which is important for the operation of the internal combustion engine. Tightening the bolts and nuts that secure the carburetor and muffler will help to verify such a malfunction. Suction can also occur due to deterioration of the gaskets, which should be replaced on the tool.
  • Fuel and air filters are elements responsible for filtering the air and the fuel mixture. If the air filter is clogged, increasing the throttle opening will not allow enough air to flow into the carburetor, causing the spark plug to flood. As a result, the engine will stall when trying to develop maximum speed. If the fuel filter is defective, the required amount of fuel does not enter the carburetor. Its lack leads to the fact that the tool cannot develop momentum, and immediately begins to stall
  • The presence of a fuel filter. This element can not only become clogged, but also detach from the fuel hose. As a result, it turns out that dirt will enter the carburetor, which will very quickly disable the mechanism.
  • A breather is a hole through which air enters the chainsaw tank, thereby eliminating the creation of a vacuum inside a sealed container. The breather is located on the lid of the gas tank or can be built into the wall of the tank. The principle of its operation is such that as the gasoline in the tank is consumed, the tank is filled with air. If the breather is defective, a vacuum is created in the tank, which prevents fuel from being pumped into the carburetor. The breather allows air to pass through in one direction, and eliminates the possibility of fuel leakage from the tank. You can repair the part using a thin needle, which punches a hole
  • CPG malfunction – the chainsaw does not pick up speed also if the cylinder-piston group is worn out. To identify this cause, it is not at all necessary to disassemble the engine to look inside. A compressor should be used to check the amount of compression. The normal value should be at least 12 atmospheres, and if the value is lower, then the CPG must be replaced
  • Ignition System – If the engine starts, it is unlikely that the problem is an electrical malfunction. However, it will not be superfluous to unscrew the spark plug and visually inspect it. The presence of black carbon indicates the need to check the ignition. The first step is to check the gap between the ignition module and the flywheel, the value of which should be 0.25 mm. The integrity of the armored wire is also checked, and if it is damaged, then it must be replaced along with the module. Spark plugs have an appropriate resource, so they need to be changed, pre-setting a gap of 0.5-0.7 mm (indicated in the technical description for each tool model)
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If checking all the reasons does not allow a positive result to be achieved, then the carburetor of the chainsaw should be removed and cleaned.

It is interesting! Make sure fuel is entering the carburetor. To do this, you need to disconnect the hose from the carburetor, and look at the activity of the stream. If the fuel flows quickly, then everything is in order, and this factor can be excluded.

When you hit the gas

If the lawn mower stops when the throttle is pressed, the reasons may be as follows:.

  • The most common option is carburetor adjustment failure, which occurs when the drive is under heavy load, after prolonged inactivity of the mechanism, or when it is used in difficult conditions..
  • Clogging of the fuel valve, which is eliminated by loosening it, as a result of which gasoline begins to flow normally through the system.
  • Loosening and drooping of the cable in the carburetor. The fuel hose may also be stretched to the point of rupture due to significant stress..
  • Clogged breather (check valve), as a result of which fuel does not enter the tank.

If the problem is related to the carburetor unit, then it can be recognized by the appearance of vibrations of the lawn mower.

08.12.2018 admin Comments No comments

Why does the trimmer stall when I press the gas? Prerequisites for stopping the trimmer at high and idle speeds, when heating or opening the air damper. What to do if the petrol trimmer starts and stalls right there?

A scythe with a gasoline drive is a necessary thing for owners of personal plots, lawns, and when the trimmer stalls at one moment, the work on cleaning the area from grass stops. The device itself is a rather complicated mechanism, therefore there are many different circumstances of its breakdowns. More often arising problems are contained in the operation annotation. To know the prerequisites why the trimmer stalls, it follows that without the help of others, it is perfectly possible to repair the device.

lawn mower stalls

Adjustment of the carburetor, does not start well, stalls when you press the gas. MY SKYPE: ork.vitek TEL. 380979677418 …


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When you hit the gas

If the lawn mower stops when you press the gas, then the prerequisites may be as follows.

  • A more common option is a carburetor adjustment failure, which appears under significant loads on the drive, after a long inactivity of the mechanism, or when it is used in languid criteria.

If the problem is with the carburetor assembly, the lawn mower vibrates to recognize it. When the hose bursts or the cable is stretched, these components are replaced.


All the prerequisites why the lawn mower does not start can be systematized according to the specifics of the operation of individual units. In the service center, malfunctions are systematized:

  • motor malfunction (piston wear, bearing malfunction, crankcase crack);
  • malfunction of the fuel consistency supply – clogged pores of the air filter or carburetor malfunction;
  • the ignition system does not work;
  • malfunction of the mechanical nature – leaking hoses, broken wires under the braid, ruptured pipes.

The user first needs to check if there is fuel in the tank. Start up in accordance with the annotation, putting the saw on its side. Set the air damper to the “closed” position, pump up fuel, turn on the ignition and make 3-4 sharp jerks with the starter. If the engine is running, open the air damper. The lawn mower does not start – we repeat the operations with a slightly open air damper.

the lawn mower cannot work for a long time. The gearbox and engine will overheat. Mows can be less than 15 = 20 minutes, taking a five minute break. On a hot afternoon, the operating time is cut in half. When mowing weeds, sedges, the working time must be reduced.

If the launch fails, we begin to find the reason for the failure:

  • check the quality of fuel;
  • make sure that the candle is working and the candle channel is clean;
  • check the cleanliness of the air filter;
  • make sure the fuel filter is not clogged;
  • check the cleanliness of the breather;
  • clean the outlet.

At high revs

When the scythe stalls at high speeds, this is due to the following problems:

  • clogging or sticking of the valve located on the gas tank cap;
  • the carburetor is out of alignment under the influence of vibrations arising from the operation of the mechanism;
  • circulation problems fuel mixture;
  • suction of atmospheric air;
  • the fuel intake hose is cracked or loose.

Adjust the carburetor referring to the trimmer operating instructions. For adjustment, it is often enough to loosen the tightening of its housing. If there are problematic points with the circulation of the fuel mixture, then it can gradually enter the carburetor. After its development, the engine stalls at high speeds.

More complex causes will be found during the diagnosis of malfunctions leading to overhaul of the carburetor. Such reasons include clogging of the internal channels of the carburetor, wear of the gasket on it and a violation of the tightness of the internal halls with a loss of vacuum. Why the lawn mower stalls what is the reason why when the engine is running at high speeds. Do-it-yourself lawn mowers repair, if it won’t start, will take patience.


At idle, common reasons for stopping the trimmer are as follows:

  • contamination, misalignment or incorrectly adjusted carburetor adjustment;
  • clogged air filter;

Replacing the air filter for lawn mowers

Trimmer air filter

  • reducing the speed of the gearbox when it heats up, which is a consequence of the use of an unsuitable fuel mixture;
  • clogged throttle;
  • air ingress into the system;
  • not enough fuel to operate the lawn mowers.

If the problem area is the carburetor, then the equipment will stop at both “cold” and “hot” start.