Lawnmower Runs For 10 Minutes, Then Dies? (Fix It Now!)

Stacy Randall
by Stacy Randall

One of life’s greatest enjoyments is sitting back and relaxing in your own backyard oasis, sipping your favorite beverage. Maintaining that tranquillity means occasionally breaking out the gardening shears and that noisy lawnmower, but machines break down over time. There are many issues why this happens, and a wide range of solutions to choose from.

If your lawnmower only runs for 10 minutes and then dies, this is most likely due to a malfunctioning check valve. Your check valve may not be letting air into the fuel tank, which will form a vacuum seal as the gas drains. This will stop the fuel from flowing to the carburetor.

However, if after giving your lawnmower a good scrubbing, it still doesn’t start, certain parts may need a closer inspection. The ideal time to work on your lawnmower would be on a dry, sunny day. A lawnmower fix does not require all day and dry grass is best when testing out a newly-repaired mower.

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Tools for the Job

  • Work gloves
  • Clean and dry washcloth
  • Stiff cleaning brush
  • Dawn dish soap or similar alternative
  • Spare spark plug
  • Spark plug wrench
  • New air filter
  • Engine oil
  • Cleaning alcohol
  • Gas (for gas-powered mowers)
  • Heat gun
  • Empty plastic bottle
  • Flathead screwdriver
  • Box knife
  • Metal spatula
  • Measuring tape

Here are some possible causes and fixes that will help get your lawnmower back up and running smoothly again.

Check the Gas Tank

Believe it or not, the most common reason for a lawnmower stalling or not starting is an empty gas tank. Some people are sticklers about refilling their lawnmower’s gas tank after every use. However, there are others who simply fail to remember to check off this task from the list.

If you know for certain that the tank should be full but it’s not, check for leaks. Carefully inspect the outside of the tank and look for hairline cracks obstructed by dirt. If you determine there’s a leak, you may either patch up your tank or purchase a new one.

Here are the steps to follow to patch up your lawnmower gas tank.

Step 1: Remove and Clean the Tank

Remove the gas tank and start washing it down with soap and water. Thoroughly scrub the tank until the smell of gasoline is undetectable. Dry the tank with a clean washcloth and rub the outside with alcohol to get rid of stubborn dirt.

Step 2: Measure and Cut the Tank

Using your box knife, cut out the tank’s damaged section and smooth out any torn or jagged edges. Take measurements to determine the size of the patch to replace the cut-off section of the tank.

Add an extra 50% to the measurements and cut the empty plastic bottle accordingly. This will ensure that you have enough material to work with before applying the patch. Always use a standard measuring device rather than just eyeballing the size of the piece you will need.

Step 3: Heat and Patch the Tank

Take the heat gun and start heating the damaged section of the tank. Ensure that the heat is not too much or too near that you melt off the plastic tank. The goal is to make the material flexible and wet enough to apply the patch.

Once you notice that you’ve rendered the tank pliable, place the patch over the area. Center the plastic as best you can and continue applying heat until you soften the patch as well. Turn off the heating gun and put it away in a safe place.

Step 4: Press and Set the Patch

With the metal spatula, apply light pressure to set the patch in place and remove bubbles that may surface. Keep the pressure at a minimum to ensure that the tank holds its form and shape.

When the patch cools off, do a visual inspection to ensure that the material is not too thin. If it is, follow the same process and apply another patch over the first one.

Step 4: Fill the Tank and Inspect

Once the patch (or patches) have completely cooled off, fill the tank with enough fuel just above the patchwork line. Carefully inspect the tank and let it sit for ten minutes to establish there is no leakage. If no liquid appears, your tank is ready and good to go.

Check the Air Filter

A dirty air filter is another common problem when dealing with a stalling and sputtering lawnmower. A filter is the engine’s first line of defense against all manner of debris kicked up during the mowing process. A clogged or worn-out filter dramatically reduces the performance of your lawnmower.

Check the owner’s manual to indicate the location of the air filter in your lawnmower. Once found, determine if it needs a thorough cleaning or a replacement. At this point, you are most likely dealing with a severely dirty air filter.

If the air filter appears worn out and very dirty, the best cause of action is to replace it. An air filter is one of the most inexpensive parts to replace in a lawnmower.

Check the Oil

Dirty or old engine oil is another factor to consider when dealing with a sluggish lawnmower. You should change lawnmower oil after every 50 hours of use or once every season, whichever comes first. Here are the steps to take to replace the oil in your lawnmower.

Step 1: Warm the Oil

Startup the lawnmower to warm up the oil allowing for easier drainage. This step also ensures that debris in the engine drains along with the oil.

Step 2: Remove the Spark Plug Wire

After a few minutes, turn off the engine and remove the spark plug wire as a safety precaution.

Step 3: Clean the Area

Wipe down the area around the oil tank to remove any debris.

Step 4: Remove the Dipstick and Prepare the Oil

Remove the dipstick and immediately place it in a small vessel to catch the dripping oil. Prepare the appropriate container for the old oil. Tilt the mower in the opposite direction of the engine air filter to avoid oil contamination to start draining.

Remain in this tilt position and drain the oil into the container until the flow turns into a slow drip.

Step 5: Replace the Oil

Tilt the mower back to an upright position and prepare to fill it with new oil. Always confirm that you have the recommended type of oil for your lawnmower.

Slowly fill the tank and be careful not to overfill. Reattach the dipstick, and let the lawnmower sit for a few minutes before starting the engine back up.

Check the Spark Plugs

This small, unassuming device is responsible for creating that electrical spark that ignites the fuel in your engine. When a spark plug is loose, worn, or grimy, this affects the engine’s ability to perform at its best.

Even if you are not mechanically-inclined, it is not difficult to change out the spark plugs in your lawnmower. Here are the steps to follow.

Step 1: Locate and Remove the Spark Plugs

Spark plugs are easy to find as a wire or cable connects them to the motor. Once located, remove the spark plug with your spark plug wrench.

Step 2: Clean and Inspect the Spark Plugs

Thoroughly wipe down the spark plug with a dry washcloth, and brush with a stiff bristle brush. Inspect the device for damages or cracks in the porcelain. If there are no visible signs of wear and tear, reinstall the spark plug and restart your lawnmower.

Step 3: Replace the Spark Plugs If Necessary

After cleaning the spark plug, check for visible signs of improvement in your lawnmower’s performance. If there is none, replace the component with a brand new one.

Once the plug is in place, hand-tighten, then use a ratchet to secure without over-tightening. Reattach the spark plug wire, then restart the mower.

Check the Carburetor

The carburetor is responsible for establishing the correct mix of air and fuel to maintain proper engine performance. A clogged carburetor on a lawnmower could cause it to stall or act sluggish. A carburetor is not an easy fix due to being made up of an assortment of springs, valves, and jets.

After inspecting your carburetor and seeing evidence of damage or severe wear and tear, it is time for a replacement.

How to Take Care of Your Lawnmower

  • Clean and wipe down your lawnmower after every use.
  • Store in a cool, dry place away from sun, snow, and rain.
  • Sharpen and balance the lawnmower blades.
  • Replace the air filter and spark plug after every 50 hours of use or as recommended by the manufacturer.
  • Change the oil after every 50 hours of use or as recommended by the manufacturer.
  • Remove the fuel if you will not use the mower for a continuous 30 days.
  • Take the lawnmower to a certified repair center for a thorough clean and inspection. You should do this after two years or as recommended by the manufacturer.

Do You Need a Mower Repair Service?

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Related Questions

How long does a lawnmower last?

If you take proper care and maintenance of your lawnmower, it should last you a good ten years or more.  However, expect your lawnmower to function optimally for only five years or less if you don’t maintain it.  

How much is a good push lawnmower?

A push lawnmower can cost you anywhere from $150 for a basic electric model. The high-end models with rear engines and all the bells and whistles can cost anywhere from $1,500-$2,000. 

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Stacy Randall
Stacy Randall

Stacy Randall is a wife, mother, and freelance writer from NOLA that has always had a love for DIY projects, home organization, and making spaces beautiful. Together with her husband, she has been spending the last several years lovingly renovating her grandparent's former home, making it their own and learning a lot about life along the way.

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