Lawnmower stalls when cutting grass. What to do.

Approx Reading Time: 8 minutes

While mowing your lawn, you notice that your mower stalls. Frustrating as this can be, this problem can be resolved relatively quickly. However, it is essential to determine why the lawnmower stalls while cutting grass because you cannot entirely fix the problem without knowing its cause. Once the cause is known, you can fix it and continue with your mowing job. This article will help you find why your mower stalls while cutting the grass and help you fix this issue.

Lawnmower stalls while cutting grass, what to do:

  1. If overheated, let it cool.
  2. Check the air filter if it is dirty.
  3. Check the carburetor; clean it if it is dirty.
  4. Check the fuel.
  5. Inspect the spark plug for signs of wear or damage
  6. Lower the height of grass if it is high.
  7. Type of grass, i.e., wet or dry.
  8. Replace old gas with fresh gas.
  9. Check the fuel cap, replace it if it is clogged
  10. Replace the restricted fuel lines.
Lawnmower stalls when cutting grass. What to do. 1
(CC BY 2.0) by raybdbomb

Lawnmower stalls when cutting grass, what to do?

Following are the three essential things needed for the lawnmower to work correctly.

  • Air
  • Fuel
  • Clean Carburetor

The loss of airflow to the engine caused by too tall or too thick grass or a dirty air filter is often why a mower engine stalls.

● 1. Being overworked:

One of the most common reasons that a lawnmower might stall while it is cutting grass is that it is being overworked that its engine is overheated during the operation. This is a mechanism that is intentionally incorporated into the mower to prevent the motor from being blown.

● 2. Check the Air Filter

The air filter of the lawnmower must be checked. In most cases, this is located at the top of the mower, over the engine. It is typically encased with either a metal or plastic shroud that allows for venting. You can find a replacement air filter at your local hardware store or online.

If the air filter is dirty, it will stop the airflow. This might be the reason that causes the mower to stall. The air mixes with the fuel inside the cylinder to dilute it. If the air filter is dirty, the dirt will move along the cylinder’s air and make the fuel dirty.

● 3. Adjust the Carburetor

If air is not the issue, then it might be the carburetor. The carburetor of the lawnmower works with the help of three adjustable screws. These screws control the consumption of the fuel. They set the amount of fuel reaching the carburetor. Minor adjustments in these screws can have a significant impact. So, the carburetor needs to be adjusted well to make it work properly.

One of the best solutions to give a start to the carburetor is the addition of a fuel primer. Older engines have a small rubber bulb that should be pushed several times to prime the engine before starting. This injects a small amount of fuel into the carburetor to help the engine start. Newer engines have an automatic choke that accomplishes the same thing without any action from the user.

● 4. Inspection of Fuel

The fuel of the lawnmower should be checked regularly. The fuel problems will most likely cause the lawnmower to stall out when it starts cutting grass.

– Stale Fuel:

The lawn mower’s fuel quality should be high because the low-quality fuel causes the system to compromise. Wrong fuel contains sticky deposits. Also, old and lousy gasoline damage your mower’s running operations, so it is recommended to use fresh fuel every season. Fuel can go stale in as few as 30 days, especially fuel mixed with ethanol as it is in many areas. Ethanol attracts moisture over time, and the moisture will dilute the gas. Other options include adding a fuel stabilizer to your tank or using canned fuel that contains no ethanol.

– Fuel Level:

Moreover, the level of fuel should be checked properly. More often, the lawnmower stalls because of the low level of fuel. So, to avoid this issue, the level of fuel should be checked.

● 5. Check plug for Sparking

You should check the spark plug for signs of damage.  If the porcelain insulator is cracked, an electron is burned away or damaged, replace the spark plug. Use the spark plug tester to check whether if it is damaged. A vital spark between the tester terminals is observed when the engine is cranking. If there is no spark, the spark plug is damaged and needs to be replaced.

● 6. Adjust the Grass

The height of the grass should be checked to avoid stalling the lawnmower. If the grass is long, it will cause the mower to hesitate. If the grass has already grown high and thick, use a string trimmer to cut the grass down to a manageable height. Cutting long grass causes overload that causes the lawnmower to shut down itself. However, if the height of the grass is low, it won’t cause any trouble. So, try not to cut the long grass with the mower directly as it will cause load and cause the mower to stall.

● 7. Wet Grass:

Another problem that can make it difficult for the mower to put out enough power is if the grass is wet. When grass is wet, it becomes much more massive than it is otherwise. It also tends to stick to the blades and the mower’s underside, adding additional stress to the motor.

The best approach is to wait until the grass has dried before attempting to mow the area. If you can not wait until it dries, you should do small areas and then turn off the mower and clean out the build-up that is present and repeat the process.

● 8. Replace Lawn Mower Gas

If none of the above problems are causing your lawnmower to stall, maybe this is the one because that is stalling your lawnmower and lousy gas. Harmful gas causes many fuel problems in the lawnmower and causes it to stall. Harmful gas tends to leave behind sticky deposits that stop fuel flow. So, the lawn mower’s harmful gas should be replaced immediately; otherwise, it will cause problems in the fuel system. If you find that the gas is harmful, replace it with a high-quality gas at once.

● 9. Fuel Caps

Another major cause is the fuel cap. Fuel caps have tiny vents on them that allow some air to get into the gas tank. These vents are essential for the proper function. If there is any problem with the vent, it will shut off the mower. To check this problem, let the air enter the fuel tank by unscrewing the gas tank slightly so that air can get into it. If the mower starts, it means that the cap needs to be changed as soon as possible. This is one of the significant causes that stall the mower.

● 10. Inspection of fuel lines:

If your mower is not running as it should, you should consider whether there is an issue with your fuel line. If you do not have experience working with fuel lines, it is probably best to seek a professional’s help. There could be build up in the line that is causing there to not be enough fuel in the engine to run at full throttle.

There could also be a small leak that is causing the problem. Having a professional investigate the issue will save you time and money in the end as they can identify the problem quickly, reducing the chances of buying parts that weren’t needed.

Frequently asked questions

1. Why my lawnmower shuts off?

Most probably, it is the vent that causes the lawnmower to shut off. These vents are the parts of the fuel’s caps. These vents allow the air to get into the gas tank. If there is any problem with the vent, the mower will shut off.

2. What can I do if my lawnmower keeps stalling?

This may be because the grass is too tall and thick. You need to cut the grass first before using a lawnmower. Also, do check for dirty air filters as the air filter may get clogged.

3. How to fix the lawnmower that dies?

You need to check if the pulley does not spin freely. It is because it leads the engine when the blades are engaged. Therefore, it is essential to oil the pulley to spins freely for the engine’s efficient working.

Final remarks:

To cut the overgrown grass of your beautiful lawn, you need a lawnmower. However, it is a gardener’s equipment that is a great invention in modern days. If it suddenly stalls while you are cutting the grass, you should keep patience and find a solution to this problem. You don’t need any experience in machinery. Instead, you can do it yourself and save your precious money. The above guidelines will help you solve your problems quite quickly. So, don’t panic if your machine stops working; keep patience and deal with these parts with love and care. If you do so, you will save your money and quickly solve your problems.