The warm weather has arrived, and you’re ready to tackle your lawn. But when you pull the cord on your trusty lawn mower, all you hear is a sputtering, coughing sound. The dreaded lawn mower sputter – a problem that can turn your weekend plans into a frustrating chore. Don’t worry! This article will guide you through the common causes of lawn mower sputtering, offering practical solutions and step-by-step troubleshooting tips to get your mower running smoothly again.
What Causes a Lawn Mower to Sputter?
Lawn mower sputtering usually signals a problem with the fuel system, ignition system, or air intake. The most common causes include:
- Fuel-related issues: Dirty fuel, clogged fuel lines, bad fuel filter, or a faulty carburetor.
- Ignition problems: Worn spark plugs, damaged ignition coil, or a faulty ignition switch.
- Air intake problems: Clogged air filter, a leak in the air intake, or a faulty choke.
Let’s Dive into the Details
Fuel System Troubles
1. Dirty Fuel or Clogged Fuel Lines
Old or contaminated fuel can gum up the fuel system, causing sputtering and poor performance.
Solution:
- Drain the old fuel: Remove the fuel tank cap and carefully drain the old fuel into a suitable container.
- Replace with fresh fuel: Add fresh, high-octane gasoline to the tank. Avoid using gas that is more than 30 days old.
Note: For long-term storage, always use fuel stabilizer to prevent fuel from deteriorating.
2. Clogged Fuel Filter
The fuel filter prevents debris from entering the engine, but it can get clogged over time, restricting fuel flow.
Solution:
- Locate the fuel filter: The fuel filter is typically located near the fuel tank or the carburetor.
- Replace the fuel filter: Remove the old filter and install a new one.
3. Faulty Carburetor
The carburetor is responsible for mixing fuel and air, and if it’s malfunctioning, it can lead to sputtering.
Solution:
- Clean the carburetor: You can clean the carburetor yourself using a carburetor cleaner kit.
- Replace the carburetor: If the carburetor is beyond repair, it may need to be replaced.
Ignition System Problems
1. Worn Spark Plugs
Spark plugs ignite the fuel-air mixture, and a worn-out spark plug can cause misfires and sputtering.
Solution:
- Replace the spark plug: Remove the old spark plug using a spark plug socket and install a new one.
Tip: Ensure the gap on the new spark plug matches the manufacturer’s recommendation.
2. Damaged Ignition Coil
The ignition coil delivers a high-voltage spark to the spark plug, and a damaged coil can prevent proper ignition.
Solution:
- Test the ignition coil: You can test the ignition coil using a multimeter.
- Replace the ignition coil: If the coil is faulty, it needs to be replaced.
3. Faulty Ignition Switch
The ignition switch controls the flow of electricity to the ignition system, and a faulty switch can prevent the engine from starting or running properly.
Solution:
- Check the ignition switch: You can test the ignition switch using a multimeter.
- Replace the ignition switch: If the switch is defective, it needs to be replaced.
Air Intake Issues
1. Clogged Air Filter
A clogged air filter restricts airflow, which can cause sputtering and poor performance.
Solution:
- Clean the air filter: Remove the air filter and clean it with compressed air or a brush.
- Replace the air filter: If the filter is damaged or beyond cleaning, replace it with a new one.
2. Air Intake Leak
A leak in the air intake can allow unfiltered air into the engine, causing sputtering.
Solution:
- Inspect the air intake hose: Look for cracks, tears, or loose connections.
- Repair or replace the air intake hose: If necessary, repair or replace the damaged hose.
3. Faulty Choke
The choke regulates airflow to the engine during startup, and a faulty choke can cause sputtering, especially when cold.
Solution:
- Check the choke cable: Make sure the choke cable is properly adjusted and operating smoothly.
- Replace the choke: If the choke is defective, it may need to be replaced.
Other Potential Causes
- Low engine oil: Low oil levels can cause engine damage and lead to sputtering.
- Dirty carburetor jets: Over time, carburetor jets can become clogged with dirt and debris, restricting fuel flow.
- Fuel pump problems: A faulty fuel pump may not be supplying enough fuel to the engine.
- Spark plug wires: Damaged or worn spark plug wires can prevent a proper spark from reaching the spark plug.
Troubleshooting Tips
- Start with the basics: Before you start troubleshooting, make sure your lawn mower has fresh fuel, enough oil, and a clean air filter.
- Check the spark plug: A simple test can determine if the spark plug is working properly.
- Listen for unusual sounds: Pay attention to any unusual noises coming from the engine, such as a clicking, grinding, or rattling sound.
- Use a multimeter: A multimeter can be helpful for testing electrical components, such as the ignition coil and the ignition switch.
When to Call a Professional
If you’ve tried all the troubleshooting steps and your lawn mower is still sputtering, it’s time to call a professional. A mechanic can diagnose the problem and make the necessary repairs.
Conclusion
A sputtering lawn mower can be a frustrating problem, but with a little knowledge and some troubleshooting tips, you can often fix the problem yourself. Remember to always practice safety precautions when working with gasoline and mechanical equipment. If you’re unsure about any repair, it’s always best to consult a professional. Now get out there and enjoy your freshly mowed lawn!
FAQs
Why is my lawn mower sputtering?
There are a number of reasons why your lawnmower might be sputtering. The most common cause is a problem with the fuel system, such as a clogged fuel filter, dirty carburetor, or bad fuel. Other potential causes include a faulty spark plug, ignition coil, or air filter. If you’ve recently used fuel that’s been sitting for a while, it could be stale and causing issues with the engine.
To determine the cause of the sputtering, you’ll need to troubleshoot the fuel system and ignition system. Start by checking the fuel filter and carburetor for dirt and debris. If they’re clean, then check the spark plug and ignition coil. If all of these components are in good working order, then the problem might be with the air filter.
How do I clean the carburetor?
Cleaning the carburetor can be a bit tricky, but it’s a fairly common fix for a sputtering lawnmower. First, you’ll need to remove the carburetor from the lawnmower. Then, you’ll need to disassemble the carburetor and clean all of the parts with carburetor cleaner. Be sure to use a soft-bristled brush to remove any stubborn dirt or debris.
Once the parts are clean, reassemble the carburetor and reinstall it on the lawnmower. You’ll also want to replace the fuel filter while you’re at it, as a dirty filter can often contribute to carburetor problems. If you’re not comfortable disassembling the carburetor, you can take it to a small engine repair shop.
What if the problem is the spark plug?
If the problem is the spark plug, you’ll need to replace it. To do this, you’ll need to remove the spark plug from the engine. You can do this by using a spark plug wrench. Once the spark plug is removed, inspect it for signs of wear or damage.
If the spark plug is worn or damaged, replace it with a new one. If the spark plug looks fine, then the problem may be with the ignition coil. You can test the ignition coil with a multimeter. If the ignition coil is faulty, you’ll need to replace it.
How can I tell if it’s the air filter?
A dirty air filter can restrict airflow to the engine, causing it to sputter. To check the air filter, simply remove it from the lawnmower and inspect it. If it’s dirty, you’ll need to replace it with a new one.
To replace the air filter, you’ll need to remove the air filter housing. This is usually done by loosening a few screws or clips. Once the air filter housing is removed, you can simply remove the old air filter and insert the new one. Then, reinstall the air filter housing.
Why is my lawnmower sputtering even after I’ve cleaned the carburetor?
If your lawnmower is still sputtering after you’ve cleaned the carburetor, there are a few other things you can check. First, make sure that the fuel lines are clear and not kinked. If they are, you’ll need to replace them.
You should also check the fuel tank for any debris or water. If there is, you’ll need to clean it out. Finally, you should make sure that the fuel cap vent is not blocked. If it is, you’ll need to clean it or replace it.
Should I replace the spark plug if it looks fine?
It’s a good idea to replace your spark plug every year, even if it looks fine. Spark plugs wear down over time, and a worn-out spark plug can cause the engine to run poorly. This includes sputtering.
Replacing the spark plug is a relatively simple task that can be done in just a few minutes. If you’re not comfortable doing it yourself, you can take your lawnmower to a small engine repair shop. They will be able to replace the spark plug for you.
What if I’ve tried all of these things and my lawnmower is still sputtering?
If you’ve tried all of the above steps and your lawnmower is still sputtering, it’s possible that there’s a more serious problem with the engine. In this case, you should take your lawnmower to a small engine repair shop.
A mechanic will be able to diagnose the problem and make the necessary repairs. Keep in mind that a small engine repair shop may not be as affordable as DIY solutions. However, if the problem is serious, it’s better to get it fixed by a professional.