How to Start a Lawn Mower That Just Won’t Start

how to start a lawn mower

So you have tried your level best, but the lawnmower is still not starting? Starting a lawnmower that has been sitting under the shed for a long time can be intimidating. This problem is pretty familiar with the users that don’t winterize the lawn mower properly.

Just pulling the starter rope won’t help, and you need to do some DIY troubleshooting to start your lawnmower to have a good experience mowing with it.

This article is a definitive guide on how to start a lawnmower efficiently without exhausting yourself. Also, we have tried and tested the below-listed ways, so we are more than sure that you will be able to start your lawnmower.

How to Start a Lawn Mower That Won’t Start

1. Check if There’s Enough Gas

Just like you cannot start your car without gas, you can’t start even the best gas lawnmowers. Check the gas tank thoroughly and make sure that it has enough gas to power the motor.

So the mower has enough gas, and still, it isn’t starting? Maybe the gas is old enough, or you haven’t emptied it at the time of storing the lawnmower. Empty the tank and then fill the gas again.

Now pull the starter rope to try starting the mower again. If you see black smoke coming out of the exhaust pipe, then it is time to change the oil.

2. Replace the Oil

Oil and gasoline are the two significant components that fuel the motor of your lawnmower. The reason why your lawnmower is discharging black smoke is due to contaminated or old oil, which needs a quick replacement.

Checking the user manual to find out what oil your lawnmower needs will be a great idea, as some models run on 10% ethanol, whereas some latest lawnmowers run on unleaded gasoline.

3. Press the Primer Button

If your lawnmower has a primer button, then there are more chances that you can start it quickly. Trigger the primer button for about three times to stimulate the gasoline tank.

The sole purpose of the primer button is to start lawn mowers that have been sitting around unused for quite some time. So you are unable to find the primer button?

Get the user manual and try to find the primer button location in it. There is a schematic diagram in most of the lawnmower user manuals that have information about different parts.

4. Check the Spark Plug

Check the spark plug thoroughly to make sure that it is secured in its place. Also, unscrew the spark plug using a wrench to clean it before installing it again. In most cases, the spark plug gets damaged if the mower is kept unused for a long time.

In this case, you have to get a new spark plug that fits perfectly with your lawnmower model. You might be able to see a black wire connecting with the spark plug (for walk-behind mowers). Inspect the cable thoroughly to ensure that it isn’t damaged, and is ready to work with the new spark plug.

Generally, spark plugs are made using metal that is prone to corrosion. If you see any marks of corrosion on the spark plug, then it is also a clear sign to replace it.

Replace the Spark Plug if needed

So you are not sure how to replace the spark plug? Follow these steps to replace the spark plug like a pro.

  • Get a wrench and unscrew the old spark plug with it. If the plug is jammed in its place, then use some lubricating spray like Liquid Wrench L212. Let the spray do its job, and then use the wrench to remove the spark plug.
  • Clean the area before installing the new spark plug as the accumulated dust and debris can damage the new plug as well. You can use a piece of cloth or a brush to clean the slot.
  • Now screw the new spark plug, tighten it with the wrench, and voila you have done it right!

5. Clean the Air Filter

Oxygen is one of the vital components every motor needs to work, and if the air filter of your mower is dirty, then it will prevent oxygen from reaching the motor. Changing an air filter is a bit challenging, but it is not impossible at all.

It’s common that air filters get clogged if the lawnmower is left unused for a prolonged time. You can easily find a new air filter for your mower on Amazon. The best way to learn how to replace the air filter is by watching a YouTube video for a clear demonstration.

6.  Check for a Loose Brake Cable

Generally, most of the users focus solely on the motor and the spark plug, but the reason your mower is not starting can be the loose brake cable. Start by checking the tension of the cable to find out if it is loose or not.

Hold the brake tightly, and inspect the cable with your hand, if you see that the cable is loose, then tighten it using the right tools. Additionally, try to start the lawnmower while holding the brake tightly. If the mower starts, then the loose cable is the only culprit.

7. Adjusting the Throttle Control

Most of the modern lawnmowers have a throttle control available at the handle that allows you to pump in more fuel and air to the motor for better performance. Toggle the throttle to its fullest, and then try to start the lawnmower.

If it gets started, then keep the throttle on the highest setting to warm up the motor. After some time, bring the throttle back to the lowest setting to continue mowing your lawn with it.

Are You Still Not Able to Start Your Mower Despite All the Efforts?

If you are still not able to start your lawnmower despite putting in your 100%, then it is the time to seek professional technician assistance. Either you can contact the manufacturer, or you can call a local technician to check what’s wrong with the mower.

But before seeking any professional help, try these troubleshooting hacks for common lawn mower problems.

8. The Starter Rope is Jammed

There can be many reasons why the starter rope is jammed, and you are unable to pull it. Check the blade and make sure that there are no grass clippings sticking around. Usually, people store their lawnmowers without proper cleaning, and it leads to grass clipping clogging the blades.

Disengage the spark plug wire to turn off the mower while inspecting the blades. If you see grass clippings clogging inside, then clean it by removing the blade.

Another reason why the rope got stuck can be to the engagement of the engine flywheel brake. If the brake is engaged, then you would not be able to pull the starter rope. Disengage the brake by pulling down the bar, and try again.

9. Mower Losing Power

So you were able to start the lawnmower, but it loses power while mowing? If this is the case with you, then focus on these primary reasons.

Dirty Air Filter

A dirty air filter prevents the oxygen from reaching the ignition chamber of the motor, and that’s why it loses power in between the mowing process.

Either you can replace the air filter with a new one, or you can clean it if possible. We recommend replacing the air filter as a filter only lasts somewhere around a year.

Poor Spark Plug Installation

Have you changed the spark plug recently? Is it securely installed in its place? Check the spark plug by turning off the lawnmower to ensure that it is installed correctly. Sometimes debris accumulates inside the spark plug slot, which creates difficulty for the motor to catch the spark.

Unscrew the spark plug and clean the slot thoroughly before installing it back in its place. In case you haven’t replaced the spark plug, then get a new one to make sure that your lawnmower works perfectly.

Loose Mower Blades

This may be a little bit surprising, but the lawnmower blades can get loose over time. Tighten the blades using a wrench, or you can even sharpen them by removing them if the edge has got dull with time.

Some Unforeseen Reasons 

When everything seems right, there can be a situation the lawnmower will lose power. if you are cutting tall grass without adjusting the height of the cutting deck, then it’s obvious that the mower will lose power, and grass clippings will get clogged around the blades.

You should adjust the height of the cutting deck based on the height of the grass. Adjusting the height of the cutting deck is easy, and you can do it with the leveler available on the handlebar of the lawnmower.

10. Lawnmower is Smoking 

If the lawnmower is smoking, then it’s an evident sign that there’s something wrong with the oil. Either you have filled the oil too much, or it is spilling inside the muffler while you are mowing your lawn. Only fill the oil to spot where you see the marking.

Filling too much oil will lead to the mower losing power, and also it will release black smoke making things more complex.

How to Maintain a Lawnmower to Keep it Running 

The best way to keep your lawnmower running is following some maintenance tips, and you can avoid all the hassles of starting it even after a long time.

1. Drain the Gasoline 

Drain all the gasoline from the tank before storing the lawnmower. It is also good for winterizing the mower because old gas can lead to certain problems while starting the mower again.

2. Check these Oil Frequently 

Keep checking the oil after some time so that you can replace it whenever needed. The oil is an essential component of the mower and therefore requires special attention.

3. Clean the Blades 

Clean the blades thoroughly before storing your lawnmower. Leaving the grass clipping as it is will result in a situation where starting the lawnmower will be a challenge for you. Remove the blade and clean out everything while lubricating the blades.

Also Read: How to Sharpen Lawnmower Blades

4. Replace the Spark Plug

We suggest replacing the spark plug every year to avoid any hassles. A spark plug is an essential yet inexpensive component that assists you in starting the lawnmower. Keep some spare spark plugs handy; so that you don’t have to rush to the nearest store to buy them.

4. Inspect the Air Filter 

Just like the oil, keep checking the air filter to confirm that it is clean and allows a decent flow of air through it. Moreover, replace the air filter every six months to make your lawn mower work like a new one.

Final Words 

Most folks think that it’s the time to give up on their lawnmower when it is not starting. But with these tips, you can save your hard-earned money by starting the existing mower. Always follow a cleaning regimen to prepare your lawnmower for another cutting session.

Also, keep up with the tips above mentioned, and winterize your lawnmower properly so that it starts without any issues, and you can keep your lawn in a neat and tidy shape.

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