You’re ready to tackle the weekend lawn care, but your mower starts sputtering and coughing, spraying gas instead of diligently cutting grass. Frustrating, right? This article dives into the common culprits behind a lawn mower spitting out gas, providing you with the knowledge to diagnose the problem and get your mower back in working order. We’ll explore the potential causes, from carburetor issues to fuel line problems, and provide step-by-step troubleshooting tips to help you get your lawn mower back on track.
In short, a lawn mower spitting out gas is usually a sign of a fuel-related issue. The most common culprits are a clogged carburetor, a faulty fuel filter, or a problem with the fuel line itself.
Fuel Delivery Problems: The Root of the Issue
A lawn mower spitting gas is a telltale sign of a problem with the fuel delivery system. The fuel needs to flow smoothly from the tank, through the lines, and into the carburetor to be mixed with air and ignited. If any part of this process is disrupted, you’ll see that telltale gas expulsion.
1. Carburetor Woes: The Most Frequent Culprit
The carburetor is the heart of your lawn mower’s fuel system, responsible for mixing fuel and air. A clogged carburetor is the most common reason for a lawn mower spitting gas. Here’s why:
- Dirt and Debris: Over time, dirt, debris, and varnish can accumulate in the carburetor’s tiny passages, restricting fuel flow. This can lead to an inconsistent fuel mixture and cause the mower to sputter and spit gas.
- Fuel Evaporation: Older gasoline can evaporate, leaving behind a sticky residue that can clog the carburetor.
- Incorrect Fuel/Oil Mixture: If you’re using a two-stroke engine mower, an incorrect fuel/oil mixture can also lead to carburetor problems.
How to Troubleshoot a Clogged Carburetor:
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Clean the Carburetor: This is the first step in fixing a clogged carburetor. You’ll need a carburetor cleaning kit and some patience. Follow these steps:
- Disconnect the fuel line: This prevents fuel from spilling while you work.
- Remove the carburetor: Refer to your owner’s manual for specific instructions.
- Disassemble the carburetor: Carefully take apart the carburetor using the tools provided in the cleaning kit.
- Clean each component thoroughly: Use a carburetor cleaner and a small brush to remove dirt and debris.
- Reassemble the carburetor: Make sure everything is properly aligned and secure.
- Reconnect the fuel line: Be sure to tighten the connections securely.
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Replace the Carburetor: If cleaning the carburetor doesn’t solve the problem, it may be damaged or beyond repair. In this case, you’ll need to replace it with a new one.
2. Fuel Filter Failure: A Hidden Culprit
The fuel filter is a small but crucial component that traps dirt and debris in the fuel line. A clogged fuel filter can prevent fuel from reaching the carburetor, causing your mower to sputter and spit gas.
How to Troubleshoot a Clogged Fuel Filter:
- Locate the Fuel Filter: The fuel filter is usually located near the fuel tank or on the fuel line between the tank and the carburetor.
- Inspect the Fuel Filter: Check for any visible dirt or debris on the filter. If it looks dirty, replace it.
- Replace the Fuel Filter: If you need to replace the filter, make sure you get one that’s compatible with your lawn mower. Follow the instructions in your owner’s manual for replacing the filter.
3. Fuel Line Troubles: A Less Common Issue
While less common, problems with the fuel line itself can also cause a lawn mower to spit gas. The fuel line may be cracked, kinked, or clogged, hindering fuel flow.
How to Troubleshoot Fuel Line Issues:
- Inspect the Fuel Line: Visually inspect the fuel line for any cracks, kinks, or damage.
- Replace the Fuel Line: If you find any problems, replace the fuel line with a new one.
- Check Fuel Line Connections: Ensure that the fuel line connections at the fuel tank, fuel filter, and carburetor are tight and secure.
Other Potential Causes: Beyond the Fuel System
While fuel delivery problems are the most common culprits, other factors can contribute to a lawn mower spitting gas. Here are a few possibilities to explore:
1. Spark Plug Issues: Ignition Trouble
A faulty spark plug can disrupt the ignition process, leading to incomplete combustion and causing the mower to sputter and spit gas.
How to Troubleshoot Spark Plug Issues:
- Inspect the Spark Plug: Check for signs of wear, damage, or fouling on the spark plug.
- Replace the Spark Plug: If the spark plug is damaged or fouled, replace it with a new one that’s compatible with your lawn mower.
2. Air Filter Obstruction: Poor Air/Fuel Ratio
A clogged air filter restricts airflow, affecting the air-fuel mixture and leading to sputtering and spitting.
How to Troubleshoot Air Filter Issues:
- Clean the Air Filter: Remove the air filter and clean it using a brush and compressed air.
- Replace the Air Filter: If the air filter is heavily soiled or damaged, replace it with a new one.
Preventative Maintenance: Keep Your Mower Running Smoothly
Regular preventative maintenance can help prevent fuel system problems and keep your lawn mower running smoothly:
- Use Fresh Fuel: Old gasoline can evaporate, leaving behind varnish and debris that can clog the fuel system. Always use fresh, high-quality gasoline and store it in a sealed container.
- Change the Fuel Filter: Replace the fuel filter at least once a year, or more often if you notice any signs of clogging.
- Clean the Carburetor: Clean the carburetor at least once a year, or more often if you use your mower frequently.
- Inspect the Air Filter: Check the air filter regularly and clean or replace it as needed.
Conclusion: Solving the Spitting Gas Mystery
A lawn mower spitting out gas is a frustrating problem, but by understanding the potential causes and troubleshooting steps, you can diagnose and fix the issue. The most likely culprits are carburetor problems, a clogged fuel filter, or a faulty fuel line. By following the steps outlined in this article, you can get your lawn mower back in working order and enjoy a smooth, hassle-free mowing experience.
Frequently Asked Questions
Why is my lawnmower spitting out gas?
This is a common issue that can be caused by several things. Most of the time, it’s a simple problem like a clogged fuel line or dirty air filter, but in some cases, it could be a more serious problem like a faulty carburetor.
Troubleshooting and fixing your lawnmower spitting out gas is easy if you follow these steps:
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Check the fuel line: The fuel line is the tube that connects the gas tank to the carburetor. If the fuel line is clogged, gas won’t be able to flow to the carburetor properly, causing the engine to sputter. To check the fuel line, simply disconnect it from the carburetor and blow through it. If you can’t blow through it easily, then the fuel line is clogged and needs to be replaced.
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Clean the air filter: The air filter prevents dirt and debris from entering the engine. If the air filter is dirty, it can restrict airflow to the engine, causing it to sputter. To clean the air filter, simply remove it from the engine and tap it gently against a hard surface. You can use a vacuum cleaner to remove any remaining debris.
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Inspect the carburetor: The carburetor is responsible for mixing fuel and air before it enters the engine. If the carburetor is dirty or damaged, it can cause the engine to sputter. To clean the carburetor, you can use a carburetor cleaning kit. If the carburetor is damaged, it will need to be replaced.
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Check the spark plug: The spark plug ignites the fuel-air mixture in the engine. If the spark plug is worn or fouled, it can cause the engine to sputter. To check the spark plug, simply remove it from the engine and inspect it. If the spark plug is worn or fouled, it will need to be replaced.
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Look for leaks: If there are any leaks in the fuel system, gas can escape and cause the engine to sputter. To check for leaks, inspect the fuel line, carburetor, and gas tank.
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Check the fuel: Old gas can cause problems with your lawnmower, such as sputtering and difficulty starting. Make sure you’re using fresh gas.
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Adjust the carburetor: The carburetor has an adjustment screw that controls the amount of fuel that enters the engine. If this screw is out of adjustment, it can cause the engine to sputter. To adjust the carburetor, you can refer to your lawnmower’s owner’s manual.
How do I know if it’s a carburetor issue?
If you’ve checked the fuel line, air filter, and spark plug and your lawnmower is still spitting out gas, then it’s likely a carburetor issue. A dirty or damaged carburetor can cause the engine to sputter, run rough, or even stall. A common symptom of a bad carburetor is a rich fuel mixture, which means that the engine is getting too much fuel.
What does a rich fuel mixture mean?
A rich fuel mixture means the engine is getting too much fuel and not enough air. This can be caused by a number of things, including a dirty carburetor, a clogged fuel line, a faulty fuel pump, or even a leaking fuel injector. A rich fuel mixture can cause the engine to sputter, run poorly, or even stall. In some cases, it can also cause black smoke to come out of the exhaust.
How do I fix a rich fuel mixture?
The best way to fix a rich fuel mixture is to clean or replace the carburetor. You can also try cleaning the fuel line and air filter, or replacing the fuel pump. If you have a fuel injector, make sure it’s not leaking.
What should I do if my lawnmower is spitting out gas after I cleaned the carburetor?
If your lawnmower is still spitting out gas after you cleaned the carburetor, then it’s possible that the carburetor is damaged and needs to be replaced. You can also try adjusting the carburetor’s adjustment screw to see if that helps.
Is it safe to run my lawnmower if it’s spitting out gas?
No, it’s not safe to run your lawnmower if it’s spitting out gas. The gas could ignite and cause a fire. You should stop using your lawnmower immediately and have it repaired by a qualified technician.
Can I just add gas line antifreeze to fix the problem?
While gas line antifreeze can help prevent fuel lines from freezing in cold weather, it won’t fix a lawnmower that’s spitting out gas. It’s important to address the underlying issue causing the problem, such as a clogged fuel line, a dirty carburetor, or a damaged fuel pump.