The sweet hum of a freshly tuned lawn mower is a summer symphony. But what happens when that melody turns into a sputtering cough and a plume of smoke? You’ve flooded your lawn mower engine. A common problem for both beginners and seasoned mowers, a flooded engine can be frustrating, but it’s a fixable issue. This article will guide you through the steps to revive your mower and get you back to mowing in no time. We’ll cover identifying the problem, understanding why it happens, and most importantly, how to troubleshoot and fix it.
Understanding the Problem
A flooded engine occurs when too much fuel enters the combustion chamber, preventing the spark plug from igniting the fuel-air mixture. This leads to a “flooded” condition where the engine won’t start. It can happen due to various factors, such as over-priming, a faulty carburetor, or a cold engine.
Identifying the Signs of a Flooded Engine
Knowing the telltale signs of a flooded engine can save you time and frustration. Here’s what to look for:
1. The Engine Won’t Start:
This is the most obvious sign. You crank the engine, but it just won’t fire up.
2. Backfiring or Popping Sounds:
You might hear backfires or popping sounds coming from the engine, indicating that the unburnt fuel is igniting in the exhaust manifold.
3. Smells of Excess Fuel:
You might notice a strong smell of gasoline around the mower, which is a clear indication of a flooded engine.
Troubleshooting and Fixing a Flooded Engine
Now, let’s get your mower back in working order. Here’s a step-by-step guide to troubleshooting and fixing a flooded engine:
1. Let the Engine Air Out:
The first step is to let the excess fuel evaporate. This is the most crucial step in fixing a flooded engine.
How to Air Out the Engine:
- Turn off the fuel valve: This prevents more fuel from entering the engine.
- Let the engine sit: Allow the engine to sit for 10-15 minutes to let the excess fuel evaporate.
- Remove the spark plug: This will speed up the evaporation process by allowing the fuel to escape.
- Check the spark plug for moisture: A wet spark plug indicates a flooded engine.
2. Try Starting the Engine:
Once you’ve allowed the engine to air out, try starting it again. If it still doesn’t start, move on to the next step.
3. Prime the Engine (If Necessary):
If the engine is still flooded, you may need to prime it. However, this should only be done if you are certain the engine is air-dried.
How to Prime the Engine:
- Locate the primer bulb: The primer bulb is typically located on the carburetor.
- Press the bulb several times: This will pump fuel into the carburetor, but do not over-prime it.
- Try starting the engine: See if it fires up.
4. Check the Spark Plug:
If the engine still won’t start, check the spark plug.
How to Check the Spark Plug:
- Remove the spark plug: Use a spark plug socket to remove the spark plug.
- Inspect the spark plug: Look for signs of wear, damage, or carbon buildup.
- Test the spark plug: Connect the spark plug wire to the spark plug and ground the spark plug to a metal surface. Crank the engine and observe for a spark. If there is no spark, you may need to replace the spark plug or check the spark plug wire.
5. Inspect the Carburetor:
If the spark plug is in good condition and the engine still won’t start, there may be a problem with the carburetor.
How to Inspect the Carburetor:
- Check for debris or obstructions: Remove the carburetor and inspect it for any debris or obstructions.
- Check the float needle: The float needle controls the fuel flow into the carburetor. If it’s not sealing properly, it could be causing the engine to flood.
- Clean the carburetor: If necessary, clean the carburetor with carburetor cleaner and a small brush.
- Replace the carburetor: If the carburetor is damaged or beyond repair, replace it with a new one.
Preventing a Flooded Engine
Now that you know how to fix a flooded engine, let’s talk about how to avoid it in the first place.
1. Avoid Over-Priming:
Over-priming is the most common cause of a flooded engine. Only use the primer bulb when necessary.
2. Use the Correct Fuel:
Using the wrong type of fuel can also cause problems. Always check the owner’s manual to determine the recommended fuel type and octane rating.
3. Keep the Carburetor Clean:
A clean carburetor will ensure proper fuel flow and help prevent flooding.
4. Don’t Choke the Engine for Too Long:
The choke restricts airflow, which helps the engine start in cold weather. However, keeping the choke engaged for too long can lead to flooding.
5. Maintain Your Mower:
Regular maintenance, including cleaning the air filter, changing the oil, and sharpening the blades, will keep your mower running smoothly and prevent potential problems.
Conclusion
A flooded lawn mower engine can be a frustrating issue, but it’s usually a simple fix. By understanding the causes and following these troubleshooting steps, you can revive your mower and get back to enjoying your well-maintained lawn. Remember, prevention is key. Proper maintenance and avoiding over-priming can save you a lot of headaches in the long run.
Frequently Asked Questions
What should I do if my lawn mower engine gets flooded?
The first thing you should do is turn off the engine and disconnect the spark plug. This will prevent the engine from starting and causing further damage. Next, you’ll need to drain the excess fuel from the carburetor. This can be done by removing the drain screw at the bottom of the carburetor or by tilting the mower on its side and letting the fuel drain out. Once the fuel is drained, you can reconnect the spark plug and try to start the engine. If it still won’t start, you may need to remove the carburetor and clean it thoroughly.
How do I prevent my lawn mower engine from flooding?
There are a few things you can do to prevent your lawn mower engine from flooding. First, make sure you’re using the correct type of fuel. Ethanol-blended fuel can cause problems with older lawn mowers, so it’s best to use non-ethanol fuel if possible. Second, be careful not to overfill the fuel tank. Overfilling can cause fuel to leak into the carburetor and cause flooding. Third, make sure the choke is properly adjusted. If the choke is stuck in the on position, it can cause the engine to flood.
How do I drain the fuel from the carburetor?
To drain the fuel from the carburetor, you’ll need to locate the drain screw. This is typically a small screw located at the bottom of the carburetor. Once you’ve located the drain screw, use a small wrench or screwdriver to loosen it. Be careful not to overtighten the screw when you’re finished draining the fuel.
How do I remove the carburetor?
Removing the carburetor can be a bit tricky, but it’s not impossible. You’ll need to locate the carburetor and disconnect the fuel line, the air filter, and the throttle cable. Once these are disconnected, you can remove the carburetor from the engine. Be sure to label the screws and bolts you remove so you can reassemble the carburetor correctly.
How do I clean the carburetor?
Once the carburetor is removed, you can clean it with carburetor cleaner. Spray the cleaner into the carburetor and let it sit for a few minutes. Then, use a small brush or cloth to scrub the inside of the carburetor. Once the carburetor is clean, let it dry completely before reinstalling it.
What if I can’t get the engine started after cleaning the carburetor?
If you’ve cleaned the carburetor and the engine still won’t start, there may be another problem. Check the spark plug to make sure it’s clean and dry. Also, check the fuel lines to make sure they’re not clogged. If you’re still having trouble, you may need to take the lawn mower to a qualified mechanic.
Can I use a different type of fuel in my lawn mower?
It’s not recommended to use a different type of fuel in your lawn mower than what the manufacturer specifies. Using the wrong type of fuel can damage the engine and void the warranty. If you’re unsure about the type of fuel to use, consult the owner’s manual or contact the lawn mower manufacturer.