How to clean a lawnmower gas tank?


The Lawnmowers fuel tanks’ primary purpose is to store gas, but they are also essential to keep your engine’s fuel clean, secure, and vented. If your lawnmower is not used for a long time, it may fail to start when you are trying to start mowing your lawn. This occurs mainly due to the residual fuel left in the tank. But also debris, old fuel, or condensation may result in a blocked fuel line. If you spot debris or dust in the gas tank, or worse, gas is leaking. It is time for fuel tank maintenance.

How to clean a lawnmower gas tank:

  • Step 1: Examine the spark plug
  • Step 2: Drain the tank
  • Step 3: Clean the carburetor
  • Step 4: Rinse the tank
  • Step 5: Check the fuel filter for deposits or debris.
  • Step 6: Install a new tank if needed

A fuel tank’s core purpose is to deliver and store enough fuel and ensure that it stays clean and prevents it from degrading. Due to the carburetor’s tiny channels, the fuel must be free from debris and clean. If you do not maintain your gas tank, your lawnmower can stop functioning soon, so start with removing the fuel and cleaning the fuel tank. This blog will help you with the necessary steps.

Steps To Clean a Lawnmower Gas Tank:

For your lawnmower’s smooth working, follow these steps to clean it yourself without calling in a professional. We have broken down the steps in simple and user-friendly instructions.

● Step 1. Examining the spark plug:

One of the most essential and core components of a gas tank is the spark plug. A spark plug serves the essential purpose of igniting the air-fuel mixture during combustion to keep your engine running. The plug consists of two leads that create an electric arc, which eventually produces the spark. Over time, carbon buildup can affect spark creation. Moreover, the electrode can also weaken due to wear and tear.

– Inspection of the spark plug:

Inspecting the plug for damage or wear and tear should help you check if the component is working or not. You should check if there is a considerable carbon buildup or if any electrode is broken or not.

– Ignition tester:

To check if the plug is producing the spark, you can use an ignition tester. The tester’s terminals will show a vital spark indicating that the component is working correctly. No spark means that the plug is defective and must be replaced.

– Replacing the plug:

You cannot repair a defective spark plug. New spark plugs are not expensive and can make a considerable difference in functioning. As a general guideline, you should refurbish your spark plug every once a year.

This is just an additional preventive measure – by chance, there are some vapors remaining that are sufficient to start the engine and rotate the blade when you’re cleaning the lawnmower as the tank. Do not clean the mower with the attached spark plug.

● Step 2. Drain the tank:

Before you get cracking, get ready with the gas container. Now, detach the fuel line attached to the carburetor. Put the gas container below the tank and drain the gas out. When the tank will be empty, use the flashlight to check for debris and beads of light that will show cracks or holes. Use a baster to remove slack debris. If you find damage, substitute or replace the tank with the original manufacturer’s equipment.

● Step 3. Clean the carburetor:

The carburetor is a crucial component responsible for providing the correct air fuel mixture and leading up to the combustion chamber. The clogging can cause the pipes to thin down, providing insufficient fuel. In extreme cases, the engine power drastically reduces and starts making a gurgling noise.

– Steps to clean the carburetor: 

  • Step 1: Remove the outer casing of the engine.
  • Step 2: Check Air Filters and their housing.
  • Step 3: Unbolt the carburetor and remove it from the fuel line.
  • Step 4: Unbolt the bowl and clean the nuts.
  • Step 5: Replace the central gasket.
  • Step 6: Replace the needle.
  • Step 7: Check All Connections.
  • Step 8: Use Carburetor Cleaner.
  • Step 9: Reassemble and reattach.

This video will give you an insight on how to follow the above steps:

– Preventive maintenance:

To enhance the lifetime of your lawnmower and to make sure that your machine will start without problems, it is wise to do some preventive maintenance

  • Fresh fuel: To ensure better performance and effectiveness of the carburetor, it is recommended that you should always use new gas for your mower. Gas will go bad after a few months.
  • Fuel stabilizer: We also recommend that you add a fuel stabilizer in the fuel tank if you plan not to use it for some time so that its quality does not deteriorate.
  • Carburetor cleaner: Carefully spray carb cleaner into the intake hole from where the fuel goes into the carburetor. Spray the cleaner into the outtake hole and spray thoroughly in the inner part of the tank. With all the grass, twigs, and debris, the need for the hour is to use a carburetor cleaner to clear out all the deposits within the carburetor, as these deposits can congest the passage of both air and fuel decrease the efficiency, thus stop the engine altogether.
  • Carburetor repair kit: You can also purchase a carburetor repair kit to help you repair and replace the defective parts.

● Step 4. Rinse the tank:

Never use water to wash the tank. Residual water can be an issue for fuel carburetors or injectors. As an alternative, rinse the tank with a little amount of gas. Now close the tank and shake it well so that gas can clean the inside of the tank thoroughly. Draw off this used gas into the old gas can. This consumed gas could not be utilized in other operational engines because this used gas will clog or damage them. Discard all old and un-used fuel in a safe way.

● Step 5. Examine the fuel filter for dust and deposits:

The oil or fuel filter is the final shield before the fuel enters the combustion process. As the name suggests, the filter is responsible for stopping impurities, dirt, and harmful objects like insects, residues and let the fuel pass only. If lousy fuel comes in contact, it may cause the filter to get clogged up and lose functionality way before its everyday life. In all this, the engine action gets rough and cause cranking issues.

  • Clean fuel: It is always preferable to use clean fuel with fuel stabilizers when the pressure has to be used. Extra fuel in the tank will always cause problems.
  • Replacement: Like all filters, fuel filters should be replaced annually unless the black residue is visible to the naked eye.

● Step 6. Reattach the fuel tank:

Reaffix an old fuel tank or mount a new one, fasten it vigorously with the cap screws. Now it is good to change the filter and fuel line. Don’t ever try to overhaul an impaired tank. It is vulnerable to leaks, fuel contamination, or fire. Many tanks use a vented gas cap to maintain the pressure difference between the environment and fuel system. If the fuel is leaking, a duly fitted back up cap can resolve the issue.

Additional Precautionary measures:

Before starting, operating, or servicing your engine, always read the engine and equipment manual or equipment to prevent property damage or personal injury.

  • Fuel and the fumes of fuel are exceptionally explosive and inflammable. Try to handle fuel with care.
  • Fuel tanks should be made of material corrosion-resistant or glazed with a corrosion-resilient substance to withstand against harmful effects of alcohol, water, or salt. The tank should be replaced if it is damaged or corroded. Use only recommended parts by the engine manufacturer if you are attempting to change the tank.
  • Some engines like those used on walk-behind mowers use a fuel filter placed inside the fuel outlet tank. These cannot be replaced – consult your local dealers on how to service in-tank filters. A filter may also be located outside the tank, midway along the fuel line.

Frequently asked questions:

1. How do you flush out a gas tank?

Remove fuel pump from the tank (prevent residual debris from falling into the tank). Put the hose into the fuel tank and start pouring a stream of clean, hot water. When the water is being filled, spray mild detergent in the tank. If opening permits, use a brush to remove debris from the sides of the tank.

2. How do you clean a metal gas tank?

A suitable cleaning solvent is acetone because of its affinity to vaporize quickly. The cleaner will help to clean the interior of the tank free of no matter what would stick. Close the cap of the tank, and then agitate it thoroughly before pouring out the solvent.

Steps to follow:

  • Step 1: Draw off any gas inside the tank into a container, which is safe to use.
  • Step 2: Detach the fuel lines running from the tank to the engine.
  • Step 3: Remove the fuel source from the top of the tank by rotating it anticlockwise until it breaks free.
  • Step 4: Wash the tank with a garden hose.
  • Step 5: Put on rubber gloves and eye protection.

3. How do you keep a gas tank from rusting after cleaning?

After that, you acid clean it, rinse it with baking soda water mixture, then use soap water for final cleansing, then put a little diesel fuel and splash it around, the fuel will coat inside of the tank and prevent it from flash rusting, then as you pass gas through it. It will create a light oily coating on it.

4. How do you get rust out of a metal gas tank?

Vinegar contains acetic acid that is used to clean corrosion. This can be done first by filling the tank with water and then draining that. Next, plug the hole and fill the tank with the vinegar, leaving it for a night to dissolve and soften the rust.

Final Remarks:

In the future, buy smaller quantities of gas to make sure you are using good-quality gas. If the gas stays for a more extended period, I will decay. Buy only that quantity of gas that lasts for 2 to 4 weeks. When you are on an extended vacation and letting your mower sit, add a fuel stabilizer to prevent fuel from degradation. When you are mowing, try to open the throttle so that you can help us with all the fuel before putting it back in the shed. When you do this regularly, the gas will not stale in the tank. Stale gas decays, damages rubber lines, corrode the tank, and produced debris and junk that destroys carburetors.

The benefits of cleaning your gas tank:

  • Improve efficiency
  • Prevent costly repair
  • Reduce emissions
  • Extend the life of your lawnmower

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