How to Get Your Lawn Mower Started After Sitting?

The sweet scent of freshly cut grass. The satisfying hum of the engine. The feeling of accomplishment after a well-maintained lawn. But then, the dreaded moment arrives – you pull the starter cord, and nothing. Your trusty lawn mower, once a beacon of summer yard work, sits there, silent and defiant. It’s happened to all of us: the frustration of trying to wake up a lawn mower after a long winter’s slumber. This article will guide you through the common reasons why your lawn mower won’t start after sitting and equip you with the knowledge to tackle those frustrating moments with confidence. We’ll cover everything from checking fuel and spark plugs to troubleshooting starting issues, and even offer some preventative measures to keep your mower running smoothly year after year.

A Quick Overview

The most common reasons for a lawn mower refusing to start after a long period of inactivity are related to fuel, spark, and the overall condition of the engine. We’ll explore each of these areas in detail, providing practical solutions and easy-to-follow steps to get your lawn mower back in action.

Fuel Issues: A Common Culprit

The first and most common culprit for a lawn mower that won’t start after sitting is stale fuel. Here’s why:

  • Fuel Degradation: Gasoline is a volatile substance and begins to break down over time, especially when exposed to air. This process produces gum and varnish that can clog fuel lines, carburetor jets, and other vital parts.
  • Ethanol’s Impact: Modern gasoline often contains ethanol, which accelerates the degradation process, making the problem even more likely with older fuel.

How to Tackle Fuel-Related Issues

  1. Empty the Tank: The most effective solution is to empty the old fuel and replace it with fresh gasoline.
    • Tip: If your mower has a fuel shutoff valve, turn it off before draining the tank.
  2. Clean the Carburetor: If the fuel system is clogged, a thorough cleaning of the carburetor is essential.
    • Tip: Use a carburetor cleaning kit specifically designed for lawn mowers. Follow the instructions carefully.
  3. Fuel Stabilizer: To prevent future issues, consider adding a fuel stabilizer to your gasoline before storing your mower for extended periods.
    • Tip: Choose a fuel stabilizer that is specifically designed for small engines.

Spark Problems: The Ignition Check

Another common reason for a lawn mower refusing to start is a lack of spark.

What to Check

  • Spark Plugs: The spark plug is responsible for igniting the fuel-air mixture. Over time, spark plugs can wear out or become fouled with carbon deposits, preventing them from generating a spark.
  • Spark Plug Wires: The wires connecting the spark plug to the ignition system can also degrade or become disconnected, interrupting the electrical circuit.
  • Ignition Coil: The ignition coil is the component that provides the high voltage required to create a spark. A faulty ignition coil can prevent the spark plug from firing.

How to Troubleshoot Spark Issues

  1. Inspect the Spark Plug: Remove the spark plug and examine it for signs of wear, fouling, or corrosion.
    • Tip: If the spark plug is worn or fouled, replace it with a new one.
  2. Test for Spark: Use a spark plug tester to check if the spark plug is receiving a spark.
    • Tip: If there is no spark, you’ll need to inspect the spark plug wires and ignition coil for potential problems.
  3. Check Spark Plug Wires: Inspect the wires for any damage, wear, or loose connections.
    • Tip: If the wires are damaged or loose, replace them with new ones.
  4. Test the Ignition Coil: Use a multimeter to test the ignition coil’s resistance.
    • Tip: If the coil fails the resistance test, it needs to be replaced.

Engine Issues: Beyond Fuel and Spark

While fuel and spark problems are common, other engine issues can prevent your lawn mower from starting. Here are some potential culprits:

Engine Oil: The Lifeblood of Your Mower

  • Low Oil Level: A low oil level can cause serious damage to your mower’s engine.
    • Tip: Check the oil level regularly and top it off as needed.
  • Dirty Oil: Over time, engine oil can become contaminated with debris and lose its lubricating properties.
    • Tip: Change the oil at least once a year or according to the manufacturer’s recommendations.

Air Filter: Breathing Easy

  • Clogged Air Filter: A clogged air filter restricts airflow to the engine, making it difficult for the mower to start and run properly.
    • Tip: Inspect the air filter regularly and clean or replace it as needed.

Other Considerations

  • Battery: If your lawn mower has an electric start, make sure the battery is charged.
  • Choke: Engage the choke if the mower is cold or has been sitting for a long time.
  • Starter Cord: A worn or frayed starter cord can make it difficult to start the mower.
    • Tip: Replace the starter cord if it is damaged.

Maintenance Matters: Preventing Starting Issues

Prevention is key when it comes to keeping your lawn mower running smoothly. Here are some essential maintenance tips:

  • Regular Inspections: Inspect your lawn mower before each use, paying attention to the fuel level, oil level, air filter, spark plug, and starter cord.
  • Fuel Stabilization: Add fuel stabilizer to your gasoline before storing your mower for extended periods.
  • Cleaning: Keep your lawn mower clean, especially the underside and the air intake areas.
  • Storage: Store your lawn mower in a dry, well-ventilated area.
  • Winterization: Properly winterize your lawn mower before storing it for the winter.

When to Call for Help

If you’ve followed these steps and your lawn mower still won’t start, it’s time to seek professional help. A qualified mechanic can diagnose and repair more complex engine problems.

Remember: A well-maintained lawn mower is a reliable companion for your outdoor chores. By addressing fuel, spark, and engine issues proactively, you can ensure your mower is ready to tackle any lawn care task that comes your way.


Here are 7 FAQs with answers to help you get your lawn mower running smoothly after it’s been sitting:

1. What is the most common reason my lawn mower won’t start after sitting?

The most common reason a lawn mower won’t start after sitting is a lack of fresh fuel. Gasoline degrades over time, losing its volatility and ability to ignite easily. This stale fuel can cause a variety of problems, from poor combustion to clogged fuel lines.

To prevent this, it’s best to drain the fuel tank and carburetor before storing your lawn mower for extended periods. If you haven’t done this, you’ll need to start by replacing the old fuel with fresh gasoline.

2. What if the fuel is fresh and it still won’t start?

If you’ve replaced the fuel and your lawn mower still won’t start, the problem could be a clogged carburetor. Old fuel can leave deposits and varnish inside the carburetor, hindering fuel flow.

You may be able to clean the carburetor yourself with a carburetor cleaner and a small brush. If the carburetor is severely clogged, you may need to replace it.

3. Should I use a fuel stabilizer?

Yes, using a fuel stabilizer is highly recommended. Fuel stabilizers help prevent the breakdown of gasoline, extending its shelf life and preventing the problems mentioned above.

Add a fuel stabilizer to your gas tank before storing your lawn mower, and follow the manufacturer’s instructions for the correct dosage.

4. What should I do if the spark plug is faulty?

A faulty spark plug can prevent your lawn mower from starting. Inspect the spark plug for signs of wear, damage, or corrosion. You can test the spark plug by removing it, connecting it to the spark plug wire, and grounding the plug against the engine block. If you see a strong blue spark, the plug is working.

If the spark plug is faulty, replace it with a new one that matches the specifications of your lawn mower.

5. What if the battery is dead?

A dead battery can also prevent your lawn mower from starting. If your lawn mower has an electric start, check the battery connections for corrosion or looseness.

If the battery is dead, you can try jump-starting it using another battery. If the battery is completely drained or damaged, you’ll need to replace it.

6. What about the air filter?

A dirty air filter can restrict airflow to the engine, making it difficult to start. Check the air filter for dust, dirt, or debris.

If it’s dirty, clean or replace it with a new one. A clean air filter will allow the engine to breathe properly and ensure efficient combustion.

7. What if my lawn mower is still not starting?

If you’ve tried all of the above steps and your lawn mower still won’t start, it’s best to seek professional help. A qualified mechanic can diagnose and repair any underlying issues that may be preventing your mower from starting.

They can also perform routine maintenance, such as oil changes and blade sharpening, to keep your lawn mower running smoothly for years to come.

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