Lawn Mower Carb Cleaning – A Step-by-Step Guide

Welcome to the world of lawn mower maintenance, where a clean carburetor is the key to optimal performance.

In this comprehensive guide, I will take you through the step-by-step process of cleaning your lawn mower’s carburetor, ensuring a smooth and efficient mowing experience.

So, let’s dive in and master the art of lawn mower maintenance!

The only tools you’ll need are a small flat screwdriver, a socket set, safety glasses and shop towels. Specialty tools are convenient, but not mandatory.

My personal carb cleaning preferences

These are my personal preferences for cleaning a carburetor (that I don’t plan to rebuild).

1. Remove the carburetor.
2. Scrape away any remaining gasket material from the carburetor and the mower.
3. Remove the jets from the carburetor after taking note of how many turns it was from fully seated.
4. I drop the entire carburetor, and jet screws, into an ultrasonic parts cleaner for 15-20 minutes.
5. I like to use dish soap as my ultrasonic cleaning solution because it works well on grease but doesn’t ruin the gaskets.
6. I also leave the emulsion tube intact unless it’s damaged.
7. I then rinse off the carb in warm water and dry it thoroughly with compressed air.
8. I reinstall the jet screws and, using a new gasket, I reinstall the carb.

The entire process isn’t difficult, it only takes patience. If you plan to clean AND rebuild the mower carb I recommend you follow similar steps but do it on a clean workbench and expect to need all the internal carb gaskets too.

The following is how I recommend others clean a mower carb properly, until they’ve cleaned a few and gained a little experience and see what works for them.

Regardless of experience level, a good carb cleaning can add years to your lawn mower lifespan.

Preparing for Carburetor Cleaning

Before we begin, take some necessary precautions to ensure your safety and the proper functioning of your lawn mower. Follow these steps:

1. Turn off the mower and allow it to cool down

   The inside of your lawn mower can get extremely hot during operation, so it’s crucial to let it cool down before starting any maintenance tasks.

2. Remove the spark plug wire

   This step is vital for your safety. Grip the spark plug wire boot (usually black) and pull it directly away from the spark plug. Make sure to pull on the plug boot itself, not the cable, to avoid any damage.

3. Set up a well-ventilated workspace

   Open all doors and windows to ensure proper ventilation. Consider using a fan to increase airflow and minimize exposure to toxic fumes.

Accessing the Carburetor

Now that you’re ready to begin, let’s locate and access the carburetor on your lawn mower:

1. Find the carburetor

   Depending on your lawn mower model, the carburetor can usually be found near the engine or beneath the air filter housing.

2. Remove the fuel tank, if neccessary

   On some mower models you’ll find that you can’t remove the carburetor without removing the fuel tank too.

   In fact, the carburetor of many mower models is mounted directly onto the fuel tank, such as with older Briggs and Stratton or Honda engines.

Cleaning the Carburetor

Cleaning the carburetor is a crucial step to remove dirt, debris, and old fuel residue that may be clogging its components. Follow these steps for a thorough cleaning:

1. Use carburetor cleaner or a brush

   Apply carburetor cleaner or use a small brush to clean the carburetor’s various parts, such as the float bowl, jets, and passages. Ensure you remove all accumulated grime and deposits.

2. Pay attention to small passages and jets

   These tiny openings are susceptible to clogs, affecting fuel flow. Use a thin wire or needle to clear any obstructions carefully.

3. Clean the fuel filter and fuel lines

   The fuel filter and fuel lines can also accumulate debris and blockages. Remove the fuel filter and inspect it for any dirt or sediment. If necessary, replace it with a new one. Clean the fuel lines using compressed air or a small brush to ensure unrestricted fuel flow.

4. Inspect and clean the carburetor gasket

   Check the carburetor gasket for any signs of wear or damage. If needed, replace it to prevent air leaks that can affect the engine’s performance.

5. Reassemble the carburetor

   Once all the components are clean and dry, carefully reassemble the carburetor, ensuring everything is properly aligned and tightened according to the manufacturer’s specifications.

Final Steps and Maintenance Tips

With the carburetor now clean and reassembled, it’s time to wrap up the process:

1. Reinstall the fuel tank

   Carefully place the fuel tank back in its position, ensuring a secure fit. Reattach any fuel lines or connections that were disconnected.

2. Reconnect the spark plug cable

   Slide the spark plug cable back onto the spark plug, ensuring a tight connection. This will reactivate the engine.

3. Test the mower

   Start the lawn mower and observe its performance. If the carburetor cleaning was successful, you should notice improved engine response and smoother operation.

4. Maintain regular carburetor cleaning

   To keep your lawn mower in optimal condition, make a habit of cleaning the carburetor at regular intervals, especially if you notice any performance issues or irregularities.

Happy mowing!