Lawnmower stalls when cutting grass. What to do. With Fixes

Are you struggling with a lawnmower that stalls while cutting grass? We’ve got you covered. With our knowledge, we can provide the assistance you need to fix your lawnmower and get it running smoothly again.

If a lawnmower stalls when cutting grass, first check for engine overheating & let it cool, then inspect the spark plug, air filter, fuel quality & level, adjust grass height & mower speed if needed, and check the carburetor, fuel cap & lines, do regular maintenance like sharpening blades & cleaning deck to prevent stalling, replace old gas & parts like spark plug if damaged.

Frustrated with your lawnmower’s unexpected breaks? We understand how annoying it can be when your lawnmower stalls in the middle of a mow. Our guide explores the potential causes and provides practical solutions. Read on to discover how to keep your lawnmower running smoothly.

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 a lawnmower might stall while cutting grass is that it is overworked and its engine is overheated during the operation. This mechanism 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. This is usually located over the engine at the top of the mower. It is typically encased with a metal or plastic shroud, allowing 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, making 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 when 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 damages your mower’s running operations, so using fresh fuel every season is recommended.

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 fuel level 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 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 grass size 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 moist, it becomes much more massive than it is otherwise. It also sticks 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 mowing the area. If you can not wait until it dries, you should do small areas, turn off the mower, clean out the present build-up, 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 that is stalling your lawnmower and lousy gas. Harmful gas causes many fuel problems in the lawnmower and causes it to slow.

Dangerous 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 the gas dangerous, immediately replace it with high-quality gas.

● 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, 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, consider whether there is an issue with your fuel line. If you do not have experience working with fuel lines, seeking a professional’s help is probably best. There could be build-up in the line that is causing there not to 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, the vent 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 spin freely for the engine to work efficiently.

Final remarks:

It would be best if you had a lawnmower to cut the overgrown grass of your beautiful lawn. However, garden equipment is a great invention in modern days. If it suddenly stalls while 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.

Regular Maintenance and Cleaning of Your Lawnmower

The health of your lawnmower dramatically affects its performance. Regular cleanup and maintenance can effectively prevent it from stalling. Debris stuck in the machine can cause mechanical failures and reduced efficiency. Therefore, it’s crucial to maintain cleanliness.

• Spark Plug Connections

The spark plug connections are among the first things to check while maintaining your lawnmower. Loose or damaged wires can affect the performance of your lawnmower. Ensure all links are tight and inspect for any visible damage.

Replace if needed. If you’re unsure, consider consulting with a certified technician or mechanic.

• Carburetor Cleaning

An often overlooked part of lawnmower maintenance is the carburetor. Over time, it can accumulate debris and experience blockage. Ensure you thoroughly inspect and clean carburetor jets and passages regularly to keep your lawnmower in shape. A fouled or dirty carburetor can lead to a range of symptoms.

• Ignition Coil Inspection

 The ignition coil is a vital part of the lawnmower. It aids in starting the lawnmower, and it needs to be in perfect condition. A faulty ignition coil can lead to issues with starting the lawnmower. Always check its function and replace it if necessary. The ignition coil works to ignite the air-fuel mixture in the engine.

• Throttle and Choke Controls

 It is necessary to check the throttle and choke controls periodically. They should work smoothly without any hitches. Lubricate them if needed and adjust them for optimal performance. These controls regulate the flow of air into the engine.

• Fuel Filter Maintenance

 The fuel filter ensures only clean fuel reaches the engine. A dirty or damaged fuel filter can affect fuel’s steady flow, negatively impacting the lawnmower’s efficiency.

Regular cleaning or replacement is necessary to ensure the fuel system operates optimally. The fuel filter prevents fuel from entering the engine from the tank vent.

• Ignition Switch and Wiring Assessment

Another significant aspect of lawnmower maintenance is the ignition switch and wiring. A faulty switch can prevent the lawnmower from starting. Make sure there are no loose connections, and replace any damaged wires.

• Checking Engine Compression

 Compression levels within the lawnmower engine must remain within the optimal range for proper combustion. An abnormal engine compression could signify a worn-out piston ring or cylinder, leading to major engine problems.

A lawn mower with perfect engine compression will run more efficiently and smoothly. If you’re unsure about this, it’s best to have it checked by a certified technician or mechanic.

• Flywheel Key Inspection

Inspect the flywheel key regularly to avoid any unexpected issues with your lawnmower. If the flywheel key gets sheared or damaged, it could cause problems with the mower’s operation. Replace the key if needed.

• Lubricate for Performance

 Ensure all moving parts of your lawnmower are correctly lubricated. This reduces friction and prevents wear and tear. Lubrication also improves performance and extends the lifespan of the lawnmower. Use high-quality lubrication products for the best results.

• Fuel-to-Oil Ratio

If your lawnmower has a two-stroke engine, maintain a proper fuel-to-oil ratio. An incorrect ratio might result in issues such as overheating or under-lubrication. Follow the manufacturer’s instructions for the correct ratio.

• Drive Belt and Transmission Inspection

The drive belt or transmission takes a lot of wear and tear. Consistent wear could affect the mower’s overall performance. Check the parts periodically and replace them if you notice excessive wear or visible damage.

• Quality of Fuel Matters

Lower-quality fuels can lead to several issues, including carbon buildup and poor engine performance. I highly recommend using high-quality, clean fuel for your lawnmower’s optimum performance.

Remember, a well-maintained lawnmower will improve its efficiency and longevity and ensure a pristine lawn for you to enjoy. That is why regular maintenance should be on every homeowner’s routine list.

If you’re unsure about what to do when your lawn and garden engine is not working correctly, it’s best to consult a certified technician or mechanic. Regular maintenance and cleaning will ensure the longevity and efficiency of your lawn and garden engine.

Regular Maintenance of Lawnmowers

Regular upkeep of your lawnmower goes a long way in preventing sudden stalling when you’re in the middle of cutting grass. Routine maintenance prolongs your machine’s lifespan while ensuring it performs optimally.

• Identifying Stalling Causes

Before you set out to fix a stalling lawnmower, it’s crucial to identify the root cause. Doing so prevents unnecessary fixes and ensures you directly tackle the problem, thus saving valuable time and resources.

• Potential Causes of Lawnmower Stalling

Several factors can cause a lawnmower to stall. The common culprits include an overheated engine, a dirty air filter or carburetor, and issues arising from the fuel. Understanding these problems is the first step to resolving them.

• Importance of Checking the Spark Plug

The spark plug is a small but vital part of your lawnmower. Look for signs of wear or damage, as this can cause stalling. It is one of the main points where electricity is converted into a spark that ignites fuel to power your machine.

• Reducing Grass Height

Sometimes, stalling can occur if your lawnmower is straining to cut too tall grass. Lowering the height of the grass to a manageable level can help improve the performance of your lawnmower and prevent stalling.

• Impact of Wet Grass on Mower Performance

Wet grass often causes a lawnmower to stall. The moisture makes the grass heavier, causing the mower to work harder and overheat. Always ensure the grass is dry before mowing to maintain peak performance.

• Fresh Gas is Vital

Old gas can cause your lawnmower to stall. Ensure you replace your gas regularly to maintain your engine’s health and guarantee a smooth mowing experience.

• Checking the Fuel Cap

The fuel cap is another small component of your lawnmower that can cause big problems. A clogged fuel cap can cause your engine to stall. Regularly check and replace your fuel cap to ensure efficient operation.

• Restricted Fuel Lines

Restricted fuel lines could cause your mower to stall. It’s essential to check your fuel lines regularly for any signs of restriction and to get them cleared or replaced if necessary.

• Lawnmower Functioning: Air, Fuel, and Carburetor Cleanliness

A lawnmower’s ability to function correctly depends heavily on a clean carburetor, good-quality fuel, and fresh air. These components should be maintained in good condition for your mower to avoid stalling.

• Consequences of Conditions Affecting the Mower’s Engine

Tall or thick grass and a dirty air filter can make your mower’s engine overheat, which could lead to stalling. Regularly clean your air filter and maintain your lawn at a manageable height and thickness.

• Air Filter Maintenance

It’s crucial to regularly check your mower’s air filter and replace it if necessary. A dirty filter can cause your engine to work harder and overheat, leading to stalling.

• Role of the Carburetor in Mower Operation

The carburetor plays a critical role in the operation of your lawnmower. It precisely mixes the air and fuel supply for combustion. Ensure your carburetor is regularly cleaned and adjusted for optimum operation.

• Fuel Quality and Level Check

Regularly checking your mower’s fuel quality and level can save you from unnecessary engine stalls. Replace any stale or low-quality fuel promptly to ensure a smooth operation.

• Fuel Cap Functionality

A functioning fuel cap is essential to allow proper airflow into the gas tank, preventing the creation of a vacuum that could choke your engine and make it stall.

• Professional Inspection of Fuel Lines

If you suspect restricted fuel lines but cannot handle it yourself, consider having them professionally inspected and serviced. The University of Vermont suggests that professional intervention guarantees a comprehensive and quality service.

• Clearing Doubts: Frequently Asked Questions

Different kinds of lawnmower stalling issues occur frequently. Familiarizing yourself with common concerns and their resolutions can help you swiftly tackle these issues when they arise.

• The Key to a Smooth Lawnmower Operation

Patience and careful attention to your lawnmower’s needs can solve most problems with the machine. Do not rush the troubleshooting process. With time and care, you can quickly fix the most stubborn stalling issues and prolong your lawnmower’s life.

Lawnmower Cleaning and Maintenance

Having a well-running lawnmower is essential for a neatly trimmed and healthy lawn. A key aspect of that performance is regular cleaning and maintenance.

• Importance of Cleaning and Maintenance

Dirty, unkempt lawnmowers are more likely to stall or die during use than their clean, regularly serviced counterparts. Frequent cleaning and maintenance can significantly extend the lifespan of a lawnmower and enhance its efficiency.

It also prevents the deposit of grass clippings, dirt, and debris, which, if left untreated, can clog the engine, reduce its efficiency, and shorten its lifespan. Environment and Human Health, Inc., affirms that well-maintained mowers reduce emissions and are environmentally friendly.

• Using the Right Kind of Fuel

Nothing can be as detrimental to a lawnmower’s operation as the wrong fuel type. Always refer to the user manual to identify the correct fuel type for a specific model.

Some models operate on gasoline, while others are designed to use diesel. Using the incorrect type of fuel can cause damage to the engine and result in sub-optimal performance.

Furthermore, emptying the fuel tank before storage is prudent, especially for extended periods. Stagnant fuel can develop moisture, leading to the growth of fungi and bacteria, which can clog the fuel system. This simple step can prevent countless issues stemming from old or bad fuel.

• Importance of Inspecting and Replacing Spark Plugs

Spark plugs play a critical role in the lawnmower’s operation, igniting the fuel and air mixture in the engine’s cylinder to power the engine.

A worn-out or damaged spark plug can struggle to ignite this mixture, causing the lawnmower to stall. Regular inspection of the spark plug can help detect any wear or damage early and replace the spark plug if needed.

A failing or worn-out spark plug can lead to several issues, from poor fuel economy hard starting, to inconsistent operation.

As part of regular maintenance, one should inspect the spark plugs and, if necessary, replace them. Regular inspection and spark plug replacement can help prevent these problems and ensure an efficiently operating lawnmower.

• When to Hire a Professional

Maintaining a lawnmower isn’t everyone’s cup of tea. It requires time, knowledge, and a fair share of physical exercise. If you have little time or find the task daunting, consider hiring a professional lawn care company.

Professional maintenance ensures your lawnmower stays in excellent condition and you get the best out of it. Lawn care professionals have the skills, expertise, and tools to thoroughly service your lawnmower and make any necessary adjustments or replacements.

Using professional services for heavy or complex maintenance tasks can be a wise decision. They will perform routine servicing, overhauls, and even part replacements, ensuring your lawnmower is always at optimum performance.

In conclusion, regular cleaning and detailing, using the correct fuel type, and inspecting and replacing spark plugs when necessary are all steps that can prevent your lawnmower from stalling or dying during use.

Hiring a professional lawn care company can be a significant relief if the maintenance becomes overwhelming. Regular servicing of your lawnmower will extend its lifespan and keep your lawn looking good.

Checking the Mower Blades for Proper Height and Speed

Knowing the recommended height and speed for your specific mower’s blades is essential in maintaining a healthy lawn. The height of your mower’s blades should be adjusted according to the type of grass in your yard.

For instance, the University of California’s Division of Agriculture and Natural Resources recommends a height of 3-4 inches for tall fescue grass. Use precise tools to measure the distance from the ground to the blade.

The speed of the mower blades is another critical factor. More speed will result in a coarse cut, while less speed will leave a neater appearance on the lawn. Always consult the manufacturer’s manual for the appropriate speed adjustments.

• Sharpening and Balancing the Mower Blades

Regularly sharpening the blades will enhance the mower’s functionality and prolong its life span. I recommend using a bench grinder for best results. A dull blade can cause numerous problems like the grass turning yellow or giving an uneven cut.

Balancing the mower blades is equally essential. An unbalanced blade can cause unnecessary wear and tear on the mower. Tools like a blade balancer are easily accessible and easy to use.

• Cleaning the Mower Deck

A clean mower deck results in better performance from your mower. Grass clippings and debris buildup can cause clogs and reduce the mower’s efficiency. This affects the cut quality and can lead to more severe issues like overheating.

There are many methods for cleaning a mower deck. Power washers, scrub brushes, or a hose can do the trick. Always remember to disconnect the spark plug before cleaning for safety measures.

• Adjusting the Cutting Height for a Clean Cut

Adjusting the cutting height not only ensures a clean cut but also contributes to the overall health of the grass. Cutting the grass too low can expose the soil to the harsh sun, leading to dry and patchy lawns.

A common requirement is that the grass should not be less than 3 inches. You’ll need to adjust the deck height accordingly using the deck lever on your mower.

• Mowing at a Slower Speed

Slow and steady wins the race – the same applies to lawn mowing. Mowing at a slower speed can enhance the cutting performance of your mower. A slower speed ensures the grass is cut evenly and reduces the chance of scalping the lawn.

Rushing can lead to blades missing patches of grass or the mower bouncing over uneven areas. Controlling the mower’s speed can directly affect the appearance and health of the lawn.

To summarize, maintaining a lawn mower adequately can lead to a healthier, more vibrant lawn. If these steps are followed accurately and regularly, you can ensure the longevity of your mower and enjoy a beautiful lawn all year round.

Engine Overheating While Mowing Thick Grass

An engine overheating is one common problem that triggers a lawnmower to stop abruptly while mowing thick grass. To address this, the first thing you’ll need to do is to turn off the mower. Allow it to cool down for several minutes before proceeding with your mowing task.

This cooling period can help prevent severe damage to your lawnmower’s engine, prolonging its lifespan.

• Importance of Maintaining a Healthy Spark Plug

Spark plugs play a pivotal role in the functionality of a lawnmower. Wear and tear or damage on a spark plug can cause your equipment to suddenly interrupt your mowing session by unexpectedly stalling in the middle of the action.

For a detailed understanding of spark plug inspection and maintenance, see this informative publication by Pennsylvania State University.

• Fuel Check: Quality and Quantity

The quality and quantity of the fuel used also significantly influence a lawnmower’s performance. Using stale or low-quality fuel, your machine may encounter problems such as stalling, making your mowing sessions longer and more tedious.

To avoid such predicaments, always ensure your lawnmower’s fuel tank is filled with fresh, high-quality fuel.

• Grass Condition and Mower Performance

The grass’s condition can impact the lawnmower’s efficiency, potentially causing it to stall. If the grass is too wet, it can strain the engine, reducing its performance.

Similarly, parched grass can choke the mower, causing it to stall abruptly. Therefore, it’s a good practice to assess your lawn’s condition before mowing.

• Fuel Cap Blockages Can Cause Stalling

The condition of your lawnmower’s fuel cap is another factor that could affect fuel flow, consequently causing the lawnmower to stall during operation. This happened to me last summer when the fuel cap on my mower got clogged.

Clearing the clog instantly fixed the stalling problem. Therefore, I strongly recommend regularly checking your lawnmower’s fuel cap for potential clogs or blockages.

• Checking Fuel Lines for Leaks or Restrictions

Last but not least, to ensure the consistent functioning of your lawnmower, it’s optimal to inspect fuel lines for any possible restrictions or leaks. These fuel lines connect the fuel tank to the engine, directly affecting its performance capabilities.

If the fuel lines have any leaks or blockages, the fuel flow to the engine would be compromised, potentially leading to stalling problems. Hence, regular inspection and prompt rectification of any issues with the fuel lines are strongly recommended.

If you are unsure how to inspect fuel lines, this guide from the University of Idaho can help you.