Lawn Mower Stalls

The petrol lawn mower will not start. Why?

The lawn mower won’t start

If at the first start, your new lawn mower refuses to start, try the following: based on the outside air temperature, set the appropriate position of the air damper (at temperatures less than 30 ° C. “damper closed”, over 30 ° C. half-closed position), then pump into the carburetor fuel and gently, but rather sharply, pull the starter handle until you feel some resistance. Repeat these steps in the same sequence several times. A brand new instrument must start. If this finally happened, you can safely get to work, having previously fully opened the damper.

If the lawn mower is no longer new, then it is necessary to start its inspection from the gas tank. If the device has not been put into action for a long time, then it is necessary to drain the old gasoline, which has the feature of "running out", ie. Lose its octane properties and refill with fresh fuel mixture. The gasoline / fuel ratio, as well as the required grades, are usually indicated in the operating instructions for the tool.

Now you need to check the spark plug. either the problem is in it itself or in the fuel system. The candle must be carefully unscrewed and its condition evaluated. If the candle is heavily flooded or there is black carbon on it, then it must be removed, cleaned and dried. Drain the excess fuel, if any, from the spark plug holes, drain the cylinder itself, then screw in the dried, or, even more desirable, a completely new plug. If the plug was initially completely dry, you need to look for a problem in the fuel supply system. Check the fuel filter first. To do this, disconnect the suction hose and remove the dirty filter from it, clean it and reinstall it, or replace it with a new one. If this does not help, you should contact the service center specialists.

Will not start after winter

In this case, you just need to drain the old and, possibly, even frozen fuel and fill in the freshly prepared mixture. Then you need to perform the same manipulations as during the first start of the lawn mower.

Starts up and stalls

If the mower stalls after starting, check the air filter. When this filter is heavily clogged with dust, it stops passing the required amount of air into the carburetor and allows dust to enter the fuel mixture. It is necessary to carefully remove the contaminated filter, clean and rinse in gasoline. If the air filter is clean, and the tool still stalls, then it is better to contact a professional to determine the cause of the malfunction and eliminate it.

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What could have broken

Problems with the lawn mower, associated with the fact that this device does not start, are classified in a special way by service specialists. They highlight malfunctions with the following mechanism nodes:

  • An engine in which the piston and bearings can wear out or fail, crack the crankcase;
  • The fuel supply system, with all this, there may be clogging of the filter or tasks with the carburetor;
  • Mechanical damage to wires, tubes, hoses;
  • Ignition circuit.

To correctly find the node where the breakdown occurred, it is necessary to note under what circumstances the trimmer stalls.

When heated

The lawn mower often stops when it heats up. At the same time, it starts, works "jerky" and gradually stops. This process occurs when the gasoline in the carburetor boils or the damper is installed in a rotary rather than disc type. In the latter case, the part is changed.

It happens that the trimmer heats up if the ignition circuit wire or coil is damaged. In order for the device to start working normally, replace parts.

The lawn mower stalls after a few minutes

Self-repair of lawn mowers

Repair of lawn mowers is carried out taking into account the mechanism of operation and the prerequisites for a breakdown of the unit. often the device fails in 3-4 years after active use.

Repair of lawn mowers is needed in the following cases:

  • The device will not start;
  • The unit rapidly stalls after starting;
  • Motor does not run at full power.


At idle, common reasons for trim stopping are as follows:

  • Dirty, misaligned or incorrectly adjusted carburetor adjustment;
  • Clogged air filter;
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Replacing the air filter for lawn mowers

Trimmer air filter

  • Reducing the speed of the gearbox when it heats up, which is the result of using 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.

And also use only the oil that is made by the manufacturer of your tool. In addition, it is important to prepare this kind of mixture in the amount that you definitely use in one or two weeks, but not more (see the proportion of gasoline and oil for a chainsaw).

Otherwise, overexposing the mixture directly in the canister will lead to the fact that it will lose all its octane properties and this will lead to significant problems with the instrument.

  • Also, the cause of a breakdown can be the direct filling of the mixture with a candle at the moment when the mechanism is started. In order to solve this problem, it is necessary to unscrew and dry the candle, but remember that it cannot be ignited in any case. Excess fuel must be drained through the hole (plug), wait 20-30 minutes, then put it back in place and try to start the tool again.
  • The chainsaw stalls when you press the gas due to the fact that there is no spark. This can happen when there is no good contact between the tip of the candle and the wire (high voltage). However, if this kind of connection works correctly, but there is still no spark, then the whole reason is the ignition unit (electronic). It is important to note that parts of this kind cannot be repaired, so they can only be replaced. Candle inspection
  • Do not forget that by examining the spark plug, you can get significant information regarding the breakdown of the chainsaw. Since if its surface is dry, then the reason for this is the cylinder, which is not directly supplied with fuel. That is why you will have to check the entire range of its presentation step by step. If the candle is covered with black carbon, then this means that the carburetor is not working properly, that is, it either supplies a lot of fuel or pours oil directly into gasoline.

    Since, for example, a Stihl chainsaw stalls when you press the gas for a simple reason, namely, a simple clogging of the direct breather.

    In order to solve this kind of problem, all you have to do is disconnect the (fuel) hose from the carburetor and pay attention to whether the fuel is leaking from it. Since if the mixture flows in a full stream, this means that the breather is not contaminated, but if on the contrary, then the cause of the breakdown has been found.

  • Here’s another reason why the chainsaw stalls when you press the gas. the muffler. It is this detail that can interfere with the full operation of the tool in cases where it is contaminated directly with exhaust resinous deposits. To do this, you just need to clean it.
  • Quite often, the Partner chainsaw stalls when pressed and the reason for this is the cylinder-piston group. Since by examining them, namely the piston and cylinder, you can easily determine the cause of the tool malfunction, directly by replacing them. You can also make a direct boring of the cylinder itself relative to the size of the new piston. Chainsaw piston
  • But if after inspection you find that there is no damage on both the piston and the cylinder, then the reason may lie directly in the rings (piston). For this kind of check, it is necessary to insert a piston into the cylinder and gently start swinging it by means of a connecting rod. Lawn mower If suddenly you feel a play then the rings need to be replaced, as they are already worn out.

    Many people ask themselves: why the chainsaw stalls when I press the gas? The answer may also lie in insufficient chain lubrication (see Chainsaw chain oil), since the oil line may leak, or the direct channels may simply be clogged. That is why pay attention to the chain, because if it is dry, then, without hesitation, start cleaning the channels that supply oil directly to the tool tire. After that, inspect in detail the parts where the oil pump fittings are connected to the pipes. But if you notice that the oil leaks at the joints, or found cracks on the pipes themselves, then in the first case, seal the leak points with a sealant, and the pipes will have to be replaced.

    When the air damper is opened

    It happens that the unit stalls when the air damper is opened, working normally at idle speed. This is due to air leaks in the system, caused by cracks in the fuel hose or problems with the oil seals. The carburetor metering system may also malfunction, and the lawn mower will stop after opening the damper.

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    Fuel hose in carburetor

    All possible reasons that lawn mower stalls, and ways to eliminate them are contained in the following

    There are many reasons for stopping lawn mowers, but the most common malfunctions associated with its carburetor. They can occur in any case. The most problematic option is when a serious breakdown occurs, and you need to purchase new parts or change the lawn mower.

    Electric lawnmower does not start or stalls

    Sooner or later, many are faced with the failure of the lawn mower. This happens, as a rule, after 3-4 years of active operation or after the device was stored in an unheated room in the winter.

    The mower is out of order if:

    • Does not start;
    • The lawn mower stalls shortly after starting;
    • Engine does not run at full power or is intermittent

    Over time, problems with the engine arise in all devices, regardless of whether a simple "Chinese" or an expensive "Japanese" is on it. The moment is unpleasant, but you should not be upset, just as there is no need to rush to the service center. You can try to repair yourself.

    How to clean a carburetor?

    You should start by checking that there are no open sources of fire nearby. Do not carry out repairs indoors. It is fraught with gasoline leakage.

    We recommend:

    Use a flat screwdriver to unscrew the screws to remove the plastic air filter cover from the motor. The removed filter is checked for clogging, cleaned with a vacuum cleaner or replaced with a new one (if the condition is unsatisfactory).

    You also need to remove the inner filter cover, which is located under the casing. It is easier to do this by unscrewing the bolts with a spanner wrench. An air hose is attached to its inside, which will also have to be removed.

    Finally, we got to the carburetor of a device that can be dismantled. Disconnecting the fuel hose going to it from the tank, i.E. Having removed the clamp, the hose is turned, trying to remove it from the pipe. You need to do the work carefully. Indeed, if there is fuel in the tank, it will surely spill.

    The carburetor is attached to the engine with two bolts, which require a union head to unscrew. When unscrewing the second bolt, try not to drop the carburetor so as not to damage the spring suspension.

    The next step is to remove the return spring. It is more convenient to carry out the operation from the side where it is attached to the motor. Now you can remove the throttle cable by gently turning the carburetor counterclockwise.

    Removing the carburetor, unscrew the bolt securing the fuel chamber cover.

    Cleaning is carried out with a special liquid or WD-40 and copper wire, from which the insulation has been stripped.

    Finally, you can remove the plastic float located under the chamber cover, which regulates the gasoline level, for which you first remove the pin.

    The camera must be cleaned of plaque. The insides of the carburetor are abundantly moistened with WD-40 (or an analogue), wiped dry. After repeating the operations several times, they clean the fuel channels with the copper core, blow them out, since their contamination is the main reason why the engine stalls or does not start.

    After completing all the steps described, assemble the carburetor in reverse order.

    After installing it in place, connecting the hose, air is expelled from the fuel chamber. This completes the repair.

    After the described manipulations, the equipment will start easily and work stably.

    Electric lawn mower malfunctions

    If the electric mower is silent, the cause may be a power outage and a broken cord. To check if there is current in the network, use another electrical device plugged into the outlet. The cord must be inspected and replaced if a break is found. Disconnect it with a hexagon, and check for a break with a multimeter.

    As is the case with gasoline lawn mowers, the cause of the inoperative electric motor can be overheating and overload (blocking of the element by a foreign object). The troubleshooting procedure is the same as above.

    Preventive work

    For trouble-free operation of the lawn mower, the owner must carry out regular maintenance after the end of the working season, i.E. Before its placement for winter storage. It will cost less than repairing or buying a new electrical device.

    One of the main measures for the reliable operation of the electric mower is keeping it clean. The mowed grass under the deck erodes metal parts. A compressor or blower will help to remove the remnants of cut weeds.

    The electric motor of the mower is air-cooled, therefore it also needs to be kept clean, which is the key to efficient operation. Suitable for cleaning the cooling fins with a soft brush and compressed air.

    If you have some experience, it is not difficult to repair lawn mowers with your own hands. Below will help with this.

    Types of malfunctions of electric mowers

    Why lawn mowers won’t start?

    To answer the question, you need to understand that all breakdowns are divided into mechanical and electrical. The first include malfunctions:

    • Knives;
    • Wheels;
    • Handles;
    • Housings.
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    To the second. everything connected with the engine, be it electric or gasoline.

    It is not difficult to repair dull knives on your own, since they are removable and you can sharpen them with ordinary emery, maintaining a sharpening angle of 30 degrees. In case of malfunctions of other parts, i.E. Housings, wheels, handles, they will also need repair or replacement.

    In battery-powered devices, battery failure is added to this problem. It is more difficult to deal with repairing a lawnmower equipped with a motor, i.E. Gasoline and electric lawn mower.

    In the first case, the problem of overheating and overloading, as well as malfunctions in the oil and fuel supply circuit, are added to possible breakdowns. An electrical breakdown can also be caused by overheating or overload, since not all models are equipped with protection.

    You will have to cool the electric motor by disconnecting it from the power supply and replace the filter. In the future, in order to avoid repairing the electrical apparatus, it must be cleaned at least once every three months.

    If there is an abnormal noise or smell, the electric lawnmower needs repair. Not everyone will do it with their own hands, because the drive will need to be replaced.

    Repairing an unexpectedly stopped electric motor

    If the engine worked, but suddenly stalled, you need to check the crankshaft and piston. they may have stuck. This is due to the lack of oil in the crankcase. With this breakdown, it is better to contact a specialist, as in the case when the electric motor of the lawn mower requires repair.

    : Lawn mower repair

    What to do if your petrol lawnmower won’t start?

    The most important point when using any technique is to comply with the basic rules of operation and its timely maintenance. This approach will ensure that your petrol lawn mower works properly and for a long time. But nevertheless, sometimes unforeseen situations happen, and the device for some reason does not want to start. In our article we will tell you about the possible causes and ways to fix this problem.

    Lawn Mower Stalls

    Faults that you can correct yourself

    When your petrol lawnmower won’t start, the first thing to do is to check for fuel in the tank. If it is missing. Top up to the correct level. Often, when the device is not used for a long time, gasoline "runs out", so it must be completely drained and refilled with new. This procedure must be done carefully so that fuel does not get on the engine, as this can lead to ignition in the future (when the engine heats up). Which gasoline is better to use, you can find out from the technical passport of the device.

    In order for the unit to start, you need to pump fuel with a primer (if it is available in this model) into the carburetor and set the maximum speed. You need to start the technique carefully. The starter cord must be smoothly pulled out until it stops, then pull it towards you in one even sharp movement.

    A problem can occur if the air damper is not correctly positioned during the first start. Depending on the air temperature, it is completely closed or set to the middle position (above 30 C). Then it must be fully opened.

    Check the air filter for dirt. To do this, turn off the machine and disconnect the wire from the spark plug. Unscrew the cover and remove the filter. Wash it with gasoline and dry it thoroughly, or just put a new one. Remember that it is recommended to change the air filter after every 25 hours of operation.

    Another reason your petrol lawnmower won’t start could be a faulty spark plug. Perhaps she was just flooded with fuel. In this case, unscrew it, clean it and check for a spark. It may not be present when the spark plug is filled with fuel. Move choke control handle (if equipped) to the CLOSED position and start the engine. If this does not help, it is better to seek help from a specialist.

    Try to constantly inspect the bottom of the machine, as any damage to it may cause the engine to stall.

    If your petrol lawn mower started up normally but stopped working almost immediately, the crankshaft or piston is most likely jammed. Another reason may be insufficient oil in the crankcase. We recommend manually moving these parts and checking the oil level with a special dipstick, you may be able to correct this problem.

    However, remember that the replacement and repair of all faulty components and elements should be entrusted to professionals from authorized service centers. Never do it yourself.

    If you want to talk to a specialist and get advice on the issue that has arisen, call us by phone: 7 (495) 135-29-39 every day from 10.00 to 20.00. We will provide all the necessary information.