Is Your Push Lawn Mower Refusing to Start? Here’s How to Fix It!

The warm weather has finally arrived, and with it comes the annual ritual of mowing the lawn. But what happens when you pull the cord on your trusty push mower, only to be met with a disheartening silence? A stubborn lawn mower that won’t start can quickly turn your lawn care dreams into a nightmare. Fear not, though! This comprehensive guide will walk you through the most common reasons why your push mower may be playing dead and provide step-by-step solutions to get it back in action.

A Quick Overview:

Most push mower starting issues can be traced back to a few key culprits: problems with the fuel system, the spark plug, or the starting mechanism. By systematically checking these components and addressing any problems you find, you’ll be back to mowing your lawn in no time.

Fuel System Check: The First Line of Defense

The fuel system is often the first suspect when a lawn mower refuses to start. Here’s how to diagnose and resolve issues related to fuel:

1. Check the Fuel Line and Tank:

  • Empty the Fuel Tank: Start by draining any old or stale fuel from the tank. Old fuel can gum up the carburetor and prevent your mower from starting.
  • Inspect the Fuel Line: Look for any cracks, leaks, or kinks in the fuel line. A damaged line will prevent fuel from reaching the carburetor.
  • Clean the Fuel Filter: A clogged fuel filter can restrict fuel flow. Locate the filter (usually near the fuel tank) and clean or replace it as necessary.

2. The Carburetor: A Potential Troublemaker

The carburetor is the heart of the fuel system, responsible for mixing fuel and air before it enters the engine.

A. Clean the Carburetor:

  • Remove the Carburetor: Refer to your mower’s manual for specific instructions on removing the carburetor.
  • Soak and Clean: Use a carburetor cleaner spray and follow the instructions on the can. Soak the carburetor components in the cleaner for a few minutes to loosen any debris.
  • Clean Thoroughly: Use compressed air or a small brush to remove any stubborn residue from the carburetor jets and passages.
  • Reassemble and Install: Carefully reassemble the carburetor and install it back on the mower.

B. Adjust the Carburetor:

  • Locate the Adjustment Screws: The carburetor will have adjustment screws for the air/fuel mixture. Refer to your mower’s manual for their locations and how to adjust them.
  • Start the Engine: Start the engine and observe the smoke coming from the exhaust. Black smoke indicates a rich mixture (too much fuel), while blue smoke suggests a lean mixture (too much air).
  • Adjust Slowly: Adjust the screws slightly and restart the engine until you achieve optimal performance and a clean exhaust.

3. Fresh Fuel is Key:

  • Use Fresh Fuel: Always use fresh, high-octane gasoline with a fuel stabilizer added to prevent it from going bad.
  • Avoid Old Fuel: Don’t use gasoline that’s been sitting for more than 30 days, as it can become stale and gum up the carburetor.

Spark Plug: The Engine’s Ignition System

The spark plug is responsible for igniting the fuel-air mixture inside the engine. If it’s faulty, your mower won’t start.

1. Inspect the Spark Plug:

  • Locate the Spark Plug: The spark plug is usually found under a metal cover on the top of the engine.
  • Remove the Spark Plug: Use a spark plug wrench to remove the spark plug.
  • Inspect the Electrode: Look for any signs of wear, corrosion, or buildup on the electrode.
  • Test the Spark Plug: Connect the spark plug wire to the spark plug and hold the electrode close to a grounded metal object (like the engine block). Pull the starter cord a few times. A bright blue spark should jump between the electrode and the grounded metal.

2. Replace the Spark Plug:

  • Choose the Right Spark Plug: Refer to your mower’s manual for the correct spark plug type and gap.
  • Install the New Spark Plug: Tighten the new spark plug using a spark plug wrench. Don’t overtighten it, as it could damage the threads.

The Starting Mechanism: Getting the Engine Turning

The starting mechanism includes the starter cord, the recoil spring, and the flywheel. Issues with this system can prevent the engine from turning over.

1. Check the Starter Cord:

  • Inspect the Cord: Look for any fraying, breakage, or binding in the starter cord.
  • Replace if Necessary: If the cord is damaged, replace it with a new one.

2. The Recoil Spring:

  • Inspect the Spring: The recoil spring provides the force needed to pull the starter cord and turn the engine. Inspect the spring for any signs of weakness or breakage.
  • Replace if Needed: If the spring is damaged, it will need to be replaced.

3. Flywheel Issues:

  • Inspect the Flywheel: The flywheel is a heavy metal disk that rotates and helps to start the engine. Look for any signs of damage or wear on the flywheel.
  • Clean the Flywheel: Use a wire brush to clean any debris or grass clippings from the flywheel.

Beyond the Basics: Other Troubleshooting Tips

If you’ve gone through the steps above and your mower still isn’t starting, here are a few more things to check:

  • Battery (for Electric Start Models): If your mower has an electric start, make sure the battery is fully charged.
  • Air Filter: A clogged air filter can restrict airflow to the engine, making it difficult to start.
  • Choke: Make sure the choke is in the correct position (usually the “run” position for a cold engine and “off” position for a warm engine).
  • Fuel Valve: Ensure that the fuel valve is open.

Safety First: Essential Precautions

  • Disconnect the Spark Plug: Always disconnect the spark plug wire before working on the engine to prevent accidental starting.
  • Wear Eye Protection: Protect your eyes from debris while working on the mower.
  • Work in a Well-Ventilated Area: Gasoline fumes are flammable and hazardous. Always work in an area with good ventilation.

Conclusion: Back to the Cutting Edge

Armed with this knowledge, you’re well-equipped to tackle most push mower starting issues. By systematically addressing fuel system problems, spark plug concerns, and starting mechanism issues, you can get your mower back in action and reclaim your lawn-mowing freedom. Remember, regular maintenance, fresh fuel, and a little bit of know-how will keep your lawn mower running smoothly for years to come.


Q1: My lawnmower won’t start at all. What should I do?

The first step is to check the basics. Make sure the fuel tank is full and the fuel line is clear. Also, confirm that the spark plug is connected and has a good spark. If the fuel and spark are fine, you may need to check the air filter for obstructions. A clogged air filter can prevent the engine from getting enough air to start.

If all of these are in order, you may have a problem with the carburetor. The carburetor mixes air and fuel, and if it’s dirty or clogged, it can prevent the engine from starting. You can try cleaning the carburetor yourself, or you can take it to a repair shop to have it cleaned professionally.

Q2: My lawnmower starts, but it dies right away. What’s wrong?

This is often a sign of a fuel problem. Check that the fuel tank is full and that the fuel line is clear. If the fuel is fine, you may have a problem with the carburetor. A dirty or clogged carburetor can cause the engine to stall. You can try cleaning the carburetor yourself, or you can take it to a repair shop to have it cleaned professionally.

Another possible cause is a faulty spark plug. A worn-out or damaged spark plug can prevent the engine from running smoothly. Check the spark plug for signs of wear or damage, and replace it if necessary.

Q3: My lawnmower starts but runs poorly. What could be wrong?

Poor running is often due to a problem with the carburetor. If the carburetor is dirty or clogged, it can cause the engine to run poorly. You can try cleaning the carburetor yourself, or you can take it to a repair shop to have it cleaned professionally.

Another possibility is a clogged air filter. A clogged air filter can restrict airflow to the engine, causing it to run poorly. Replace the air filter if it is dirty or clogged.

Q4: My lawnmower is making a strange noise. What does this mean?

A strange noise could indicate a number of problems. If the noise is a grinding or scraping sound, it could mean that the blades are dull or damaged. If the noise is a rattling or knocking sound, it could mean that the engine is damaged. It’s important to stop using the lawnmower and have it inspected by a professional if you hear a strange noise.

If the noise is a high-pitched whining, it could mean the engine is running too fast. This could be due to a problem with the throttle or the governor.

Q5: My lawnmower is spitting out smoke. What should I do?

Smoke coming from your lawnmower is not a good sign. It could mean that the engine is burning oil. This could be caused by a number of problems, including worn piston rings, a damaged valve, or a clogged oil filter.

If the smoke is black, it could mean that the engine is running too rich. This could be caused by a problem with the carburetor or the fuel system.

Q6: How can I prevent my push lawnmower from needing repairs?

The best way to prevent your push lawnmower from needing repairs is to perform regular maintenance. This includes:

  • Changing the oil: This should be done every 25 hours of use or at least once per season.
  • Cleaning the air filter: This should be done every 25 hours of use or more frequently if you mow in dusty conditions.
  • Checking the spark plug: This should be done every 25 hours of use or more frequently if you notice the engine running poorly.
  • Checking the fuel lines: Ensure the fuel lines are clear of debris and any leaks.

Q7: Where can I find replacement parts for my push lawnmower?

You can find replacement parts for your push lawnmower at a variety of places, including:

  • Online retailers: Amazon, eBay, and other online retailers often sell parts for push lawnmowers.
  • Local hardware stores: Home Depot, Lowe’s, and other hardware stores often carry parts for push lawnmowers.
  • Lawn mower repair shops: Lawn mower repair shops typically have a wide selection of parts for push lawnmowers.

Before you purchase parts, be sure to identify the model number of your lawnmower so you can find the correct parts.

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