The Lawn Mower Starts And Stalls

Petrol Lawn Mower Will not start. Why?

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.

The lawn mower won’t start

If at first start your new lawnmower refuses to start, try the following: Based on the outside air temperature, set the appropriate air damper position (at temperatures below 30 ° C). Damper closed, over 30 C. Semi-closed position), then pump fuel into the carburetor and gently, but rather sharply, turf to the feeling of some resistance to the starter handle. 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 activated for a long time, then it is necessary to drain the old gasoline, which has the peculiarity run out of breath, those. Lose its octane characteristics, 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 itself, or in the fuel system. The candle must be carefully removed and 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.

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.

Electric lawn mower 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 winter in a not very heated room.

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

Eliminating the reasons why the lawn mower won’t start

The fuel mixture must be prepared with the exact proportions of gasoline and oil. In this case, you cannot use another brand of fuel. To exclude the ingress of dirt, gasoline must settle in glass or metal containers for 2 days.

Do not use plastic utensils for storing fuel. Measure the oil accurately with a medical syringe without a needle. Use only freshly prepared mixture. Do NOT leave used fuel in the tank. If the engine is naughty, the lawn mower stalls, when you press the gas, the fuel may be to blame.

The lawn mower starts and stops. How to identify the cause of a breakdown

You need to start repairs, guided by the principle from simple to complex, those. It is recommended to start repairs by checking the presence of gasoline in the tank. If the gasoline device stops after wintering, the fuel should be replaced.

After all, the fuel, unfortunately, is not always of decent quality. Consequently, during prolonged inactivity of the device, it may delaminate or form deposits. And motors are sometimes very sensitive to fuel quality.

If there are doubts as to the latter, but the mower does not start, it is necessary to check the spark by removing the wire with a cap from the spark plug, unscrewing it with the wrench supplied in the kit.

If an unstable and weak spark appears, the candle will need to be cleaned with a file or sandpaper.

Another problem that is easy to fix is ​​a clogged fuel hose. Check this by disconnecting it: if the fuel does NOT flow, then the filter or saloon is clogged. The filter will have to be replaced, the saloon can be cleaned with a needle.

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It’s good if the mower works after that. However, the cause of the problems in 90% of cases lies elsewhere. Failure of the carburetor, which will require repair. It is possible to cope with the repair with enough experience. If it is absent, you will need the help of the service center.


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

  • Motor malfunction (piston wear, bearing malfunction, crankcase crack)
  • Fuel consistency supply failure. Clogged air filter pores or carburetor malfunction;
  • The ignition system does not work;
  • Malfunction of mechanical disposition. Leaking hoses, broken wires under the braid, bursting pipes.

The user first needs to check if there is fuel in the tank. The start-up is carried out in accordance with the annotations, put the dust on its side. Set the air damper to position closed, pump up fuel, turn on the ignition and make 3-4 sharp jerks with the starter.

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

If the launch fails, we start 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;
  • Cleans the outlet.

All the prerequisites why
Does not start
lawn mower, can be systematized according to the specifics of the work of SEPARATE nodes. In the service center, malfunctions are systematized:

  • Motor malfunction (piston wear, bearing malfunction, crankcase crack)
  • Fuel mixture supply malfunction. Clogged air filter pores
    either carburetor malfunction;
  • The ignition system does not work;
  • Malfunction of mechanical disposition. Leaking hoses, broken wires under the braid, bursting pipes.

How to clean a carburetor

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 inner side, 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.

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.

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

I installed it in place by connecting a hose, air is expelled from the fuel chamber. This completes the repair.

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

Further verification

If the piston moves, then you must first check the fuel supply, for which the candle is carefully wiped with a dry clean cloth, then screwed into place, and the position regulator is set with the air damper to Off, as when starting the engine.

Then move the choke lever to the On and unscrew the candle, which is carefully examined.

Wet contacts indicate that gasoline is entering the engine and an ignition problem, while dry contacts indicate:

  • On carburetor models in a faulty carburetor;
  • On mower with fuel injection malfunction of the entire fuel system.

In both cases, knowledge and equipment are needed for correct diagnostics and repairs, therefore, for those who DO NOT understand such work, it is better to take the device for repair to a specialized workshop.

If fuel is supplied, then it is necessary to check the external condition of the ignition coil and high-voltage wire. If they have cracks or poor contact both between the manual and the coil, and at the point where the wire is connected to the spark plug, they must be replaced.

If everything is fine, then you need to check the Spark, for which you can use both a known-good candle and a bolt of a suitable diameter, which is inserted instead of a candle into a high-voltage wire.

The candle is threaded against the ribs of the engine cooling jacket, and the bolt is positioned so that it does NOT come into contact with the mower body or its engine anywhere, and the distance from it to the cooling jacket was 1-2 mm.

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After that, disconnect any wire going to the ignition switches, then pull the manual starter lever several times or press the electric button and see if a spark appears.

If there is a spark, then the device will not start for one of the reasons:

  • Breakdown or breakage of the ignition coil;
  • Flywheel key cut;
  • The ignition magnet fell off the flywheel.

To repair THESE damage skills and equipment are required, so those who do not have them are better off trusting professionals. If there is a spark, then the problem is in the spark plug, so after replacing it, the engine will start working.

Engine won’t start

There are quite a few reasons why the engine does not start:

  • Empty fuel tank;
  • Clogged air filter;
  • The muffler is clogged;
  • The ignition switch is in the wrong position or defective;
  • The choke lever is in the wrong position;
  • Defective candle;
  • Broken or clogged carburetor.

The device does not drive well

The most common causes of such a malfunction are:

  • Incorrect wheel drive cable adjustment;
  • Plugged bushings or wheel bearings;
  • Leaking lower engine crankshaft oil seal;
  • Poor or too large drive belt.

It is necessary to start the test by adjusting the wheel drive cable, this procedure is described in detail in the manual for the petrol lawn mower.

It is necessary to move the cable adjustment so that the drive engages with less pressure on the lever. If this does not help, it is necessary to return the cable to its original state, then prepare the mower for changing the belt, all preparatory actions are also described in detail in the operating instructions.

Even the drive wheels connected to the gearbox must, albeit with effort, but rotate when they are turned by hand. Another pair of wheels, not connected to the gearbox, should turn much more easily. If the drive wheels cannot be rotated with one hand, it means that the gearbox requires maintenance or replacement, at home this should be done only if you have extensive experience in repairing such equipment.

If the drive wheels do not rotate tightly, then it is necessary to check the condition of the bushings, by which they are connected to the mower body, possibly clogged with grass. To cope with such a problem, it is necessary to remove the wheels, then pull the shaft out of the bushings and clean all the elements of adhering grass, a detailed description of this operation is in the operating instructions for the lawn mower.

To carry out the following steps, at least a minimum of locksmith and repair experience associated with any motorized equipment is required. If you do not have such experience or you are NOT sure that you can handle it, it is better to entrust the performance of THESE work to a specialized workshop or service center.

After draining the oil and gasoline, the gasoline lawnmower is placed on the table, turning the muffler to the bottom or with the wheels towards the top.

Then remove the knife and belt guard (all these operations are described in detail in the operating instructions for the lawn mower) and check the tension of the latter, and also look for traces of oil.

If the belt is very stretched, then it must be replaced with a new one, this can be done independently, however, certain locksmith skills will be required.

If there are traces of oil, then it is advisable to deliver the device to a service center, because special equipment and certain skills are needed to repair it.

Initial inspection

To determine the real cause of this defect, you must first carry out a complete visual inspection and make sure that the air filter or muffler holes are NOT clogged, there is gas in the tank, and the throttle control lever and ignition switch are in the correct position.

If everything is in order with this, then it is necessary to perform pre-start work, including cleaning the air or fuel filters, described in detail in the mower‘s operating instructions, and then try to start.

After making sure that the engine still does not start, the mower is placed on the table and proceeds to a more detailed search for the reasons.

First, unscrew the spark plug and tightly plug the plug hole with your finger, then smoothly but quickly and strongly pull the recoil starter cable or press the electric start button.

The moving piston must create enough air pressure to push the pin through and out. If this does not happen, then the motor needs serious repair, which is difficult to do at home, so it is better to take the mower to a specialized workshop.

After all, the premise that the piston does NOT follow the starter rope or the rotation of the electric starter shaft may be:

  • Breakage of the starter, due to which it does not transfer rotational energy to the engine shaft;
  • Sheared flywheel key that links the flywheel and starter to the engine and also ensures the correct firing angle.

To eliminate both malfunctions, not only tools are needed, but also skill, therefore, for those who do not have the skill to repair any engines, it is better not to try to fix such problems yourself.

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The engine does NOT pick up or keep revving

The most common reasons why the engine is NOT revving up are:

  • Incorrect position of the choke lever or breakdown of its drive;
  • Dirty air filter;
  • Faulty manual accelerator control system.

At home, without special equipment and skills, you can only check:

  • Air filter condition;
  • Choke lever operation (only on models where the choke position is manually adjusted)
  • Manual accelerator control system, that is, a special lever on the folding handle and a cable connecting it to the carburetor.

Checking the condition of the air filter and flushing it is described in detail in the mower’s operating manual, and we analyzed the check of the throttle position regulator in the previous section.

To check the manual accelerator control system, set the lever to a position where the engine speed will correspond to the required for mowing, then mark its position with a marker and, after waiting for them to decrease, compare the position of the lever to the mark.

If the lever matches the mark, then the problem is much more serious and you need to contact the service, if the lever has moved, then you need to replace it.

Some inexpensive Chinese devices are supplied with a factory defect, including an incompletely assembled air damper actuator or improper adjustment.

Many modern lawn mowers are equipped with automatic speed control, so they can only be diagnosed in a workshop.

Cuts grass poorly

If after the mowing the grass looks clumpy, then there is always one reason for this. A dull knife that either needs to be eaten or replaced.

An improperly sharpened knife quickly becomes dull and loses balance, which can lead not only to vibration, but also to rapid wear of the engine bearings. If the knife can be sharpened, then do it as described in the previous section.

What to do if the petrol lawn mower 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. Still, sometimes unforeseen situations happen, and for some reason the device does not want to start. In our article we will tell you about the possible causes and ways to fix this problem.

Faults that you can correct yourself

When your petrol lawnmower will not start, the first step is to check that there is 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 fizzles out, therefore it must be completely drained and filled with new. This procedure must be done carefully so that fuel does not get on the engine, as this can lead to further ignition (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 cord must be pulled out smoothly until it stops, then pull it towards you with one even sharp movement.

Malfunction 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 prerequisite for a petrol lawn mower will not start may 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. Set the choke control knob (if equipped) to position CLOSED 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 prerequisite can be an insufficient amount of 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 a question that has arisen, call us by phone: 7 (495) 135-29-39 every day from 10.00 to 20.00. We provide all the necessary information.

The Lawn Mower Starts And Stalls