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How to clean a rusty lawnmower gas tank, step by step

A fuel tank’s fundamental task is to store and supply gas to the engine and ensure that the gas stays clean. If the fuel contains dirt, it can clog the carburetor. This can result in a poorly starting lawnmower and can eventually stop working altogether. A fuel tank that is not a good condition can be a source of dirt and debris that gets mixed with the fuel. Before this can happen, you need to make sure that you clean your fuel tank.

When your lawnmower is older and uses a metal gas tank, one of the more common reasons for clogging the carburetor is rust. When you notice this, you can replace the gas tank or clean it. Cleaning can take some time but will be a lot cheaper than replacing it. This blog will help you with the needed steps to clean a rusty or eroded gas tank yourself.

How to clean a rusty lawnmower gas tank, step by step:

  • Step 1. Make sure that the lawnmower can not accidentally start
  • Step 2. Drain the tank
  • Step 3. Preventively clean the carburetor
  • Step 4. Rinse the tank with different techniques
  • Step 5. Check the fuel filter for deposits, dirt, or debris.
  • Step 6. Close the tank and reattach it
(CC BY 2.0) by rbarnesdotcom

Cleaning a rusty lawnmower tank Step-by-Step:

Cleaning your gas tank is not a difficult task. But before you start with the cleaning, you first should look at some preventive measures. Then we can look into the steps in more detail. What tools do you need, and what is required to finish each step.

● Step 1. Make sure that the lawnmower can not accidentally start

The first step is to make sure that your lawnmower can not start unintentionally. An easy way is to remove the spark plug cables. If there is a little bit of fuel left in the system, this will make sure that the engine can not start while working on it.

Also, make sure that you park the lawnmower in a location with a hard floor capable of dealing with some fuel spill.

● Step 2. Drain the tank

After opening the cap, get prepared with the gas container. Now, remove the fuel line attached to the carburetor. If your lawnmower is liquid fuel operated, drain the fuel into a tank. If it is gas operated, let the air pass out in an open environment. Make sure that you have no source of heat or spark present near it. When the tank is empty, use the flashlight to inspect for dirt, debris, and beads of light that will show cracks or spores. You can use a simple scrapper or blade to remove the slack debris. If you discover the damage in the tank that is too major, stop right there. Either replace it or take it to some expert.

● Step 3. Clean the carburetor thoroughly 

The carburetor is a vital component responsible for the correct air-fuel mixture and leads to the combustion chamber. As it is directly connected to the fuel tank, the dirt and rust from the tank may propagate to its core. Now, if you have opened the machine, cleaning the carburetor is a mandatory step. The clogging or congestion causes the foundation of pipes to thin down, providing inadequate fuel. In extreme cases, the engine power severely reduces and starts making a gurgling or burbling noise.

Cleaning it is simple. Use a pneumatic pump to wipe away the dirt from the insides using strong air pressure. Check the fuel lines, air intake, distributor connected to it; clean them all thoroughly with a petrol wash and air pressure. Make sure that you adjust the right tubes into the right places when you’re done cleaning.

● Step 4. Rinse the tank with different techniques

Now, it is time to get back to the gas tank, especially for the rusty gas tank to be dealt with. Removing the gas tank is pretty simple. You will find 2-3 nut bolts at the bottom. Grease them and remove them carefully. In some lawnmowers, you will have to remove the carburetor first to remove the gas tank. The rust can be removed using the following techniques:

– Abrasive

Abrasive materials are ordinary for confiscating rust from gas tanks. Pea or aquarium gravel and plain gravel are widely used abrasive materials, scrubbing away the rust effectively.

All the gravel must come out of the tank after applying this method. It is recommended to use a liquid like water or an amalgamation of soap and water, which aids the abrasive material and extricates the dust particles.

– Chemicals

Vinegar and baking soda are widely used chemicals. Muriatic acid or isopropyl alcohol is beneficial in loosening the rusty stuff. Using a mixture of abrasives and chemicals can be highly effective for removing rust. You have to ensure that the amalgamation of different substances is compatible not to damage the tank further. In less severe cases, simply using WD-40 will solve your problems.  

– Electrolysis

Carrying out electrolysis to get rid of rust is beneficial for smaller objects; however, it can be used to remove rust from a gas tank with a few amendments. It is significant to practice caution when linking and detaching the power or voltage source, make sure that the ferrous metal is not exposed to the edge of the gas tank. Probably it is better to ask an expert for help with this method.

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

The oil or fuel filter is the final stage before the fuel comes into the combustion process. As the filter’s name suggests, it is responsible for preventing impurities, dirt, and dangerous objects such as insects and residues and let the fuel pass through only. If insufficient or dirty fuel comes in contact, it may become the prime reason for clogged up and lose functionality. In all this, the engine action gets rough, lumpy, and can cause stalling problems.

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

● Step 6. Reattach the fuel tank

Fix the old fuel tank properly. Fasten it tightly with the cap screw. Ensure that the connections with the carburetor are proper. Use mild greasing while tightening a nut anywhere. Now it is good to change the filter and fuel line. You may use the liquid fuel you stored. However, add some anti-knocking agents to it, along with fuel stabilizers. Engage the spark plug, and you’re ready to go.

Additional Precautionary actions:

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

  • Protection: Goggles and facemask must be used for protection.
  • Ventilation: It is recommended to work in a well-ventilated area to avoid full exhausts.
  • Chemicals: Mixing products will cause corrosive chemical reactions. So only amalgamate those chemicals, which are defined on the manufacturer’s instructions.
  • Explosion: Ensure that heating and energy sources are far from the area before removing the gas tank.
  • Gas Storage: Gas must be stored appropriately, and keep an extra tank nearby to dilute any chemicals’ spillage.

Frequently asked questions:

1. How do you clean a gas tank that has been sitting?

Fill the tank with water at once. Add a half gallon of muriatic acid into the tank. For a few seconds, shake a tank properly. Make it sit for a minimum of 24-hours so that proper residual vanish out, and you get a clean and clear tank. In doing so, make sure that you have no fuel in the tank and the spark plug has been removed.

2. Does vinegar dissolve rust?

Yes, it can dissolve rust. Persistent rust is best removed by using white vinegar. To dissolve rust is the best way to use acetic acid, which is a familiar domestic product. You can immerse minor things such as earrings or rings, then wipe them onto a rusty surface with some rag or cloth. By just pouring it directly over rust spots will remove the rust. Apply this anti-rust technique on the bolts and screws that have rusted together.

3. How do you clean the inside of an old gas tank?

Remove the fuel pump from the tank and ensure no residual debris or dirt falls into the tank. Attach the hose into the fuel tank and shoot down a stream of hot and clean water. Keep filling the water and at the same time spray mild detergent in the tank. If opening lets, use a brush to loosen dirt, twigs, and debris from the tank’s rims.

Final Remarks:

Learning how to clean rust out of a gas tank will save you time and is cheaper than replacing it. There are several ways to remove rust inside a gas tank. A clean and well-maintained gas tank will help evade the potential negative influences corrosion can cause to your lawnmower. Different approaches, such as abrasives (gravel or washers), acids like muriatic acid or vinegar or, battery and washing soda, are useful to solve the rust issue. You can also use the methods mentioned above in an appropriate mix if the rust problem is severe. In case the rust has left holes in the gas tank, it is better to take it to a professional. You might need to replace it now.

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  1. Mason Anderson says:

    I appreciate the additional precautions provided to ensure safety while cleaning the tank.

    • Allard Vdhooft says:

      Thank you, Mason Anderson! Safety is a top priority while cleaning a gas tank. I’m glad you found the precautions helpful. Stay safe and happy cleaning!

  2. Dwight Brooks says:

    What precautions should one take when cleaning the fuel filter?

    • Allard Vdhooft says:

      When cleaning the fuel filter, take the necessary precautions to prevent injury and damage to property. Always refer to the equipment manual for safety guidelines. Stay safe!

  3. Richard Butler says:

    Is it recommended to clean the gas tank myself or seek professional help?

    • Allard Vdhooft says:

      It’s best to seek professional help to clean a gas tank with rust or other issues to ensure it’s done safely and effectively. Your lawnmower’s performance depends on it.

  4. Layla Lee says:

    What type of fuel stabilizers should be used when reattaching the tank?

    • Allard Vdhooft says:

      Use a fuel stabilizer like Stabil or Sea Foam when reattaching the tank to prevent rust and dirt buildup. Regular maintenance is key to keeping your lawnmower running smoothly.

  5. Sharlene Sims says:

    How often should I clean my lawnmower’s gas tank to prevent rust?

    • Allard Vdhooft says:

      To prevent rust and clogs, clean your lawnmower gas tank annually or whenever you notice issues. Follow these steps for a successful cleaning process.

  6. Crystal Perkins says:

    Thank you for explaining the importance of maintaining a clean gas tank for a lawnmower.

    • Allard Vdhooft says:

      Thank you for reading! I’m glad you found the information on maintaining a clean gas tank for a lawnmower helpful. Happy mowing!

  7. Perry Hill says:

    I never knew about the importance of checking the fuel filter, thanks for the tip!

    • Allard Vdhooft says:

      Thank you, Perry! Keeping the fuel filter clean is crucial for your lawnmower’s performance. I’m glad you found the tip helpful!

  8. Martha Carr says:

    Is it safe to use abrasive materials like gravel inside the gas tank?

    • Allard Vdhooft says:

      Thank you for your question, Martha. Abrasive materials like gravel can be used to clean a gas tank, but it’s essential to ensure all the gravel is removed before refilling to prevent clogging issues.

  9. Harvey Moreno says:

    What should I do if I encounter major damage or holes in the gas tank while cleaning it?

    • Allard Vdhooft says:

      If you encounter major damage or holes in your gas tank while cleaning it, it may be best to replace it or consult a professional for repair. Safety first!

  10. Genesis Payne says:

    Great step-by-step guide for cleaning a rusty gas tank, very informative!

    • Allard Vdhooft says:

      Thank you, Genesis! I’m glad you found the guide informative. Feel free to reach out if you have any more questions or need further assistance. Happy cleaning!

  11. Diane Rose says:

    Can I use a different method besides electrolysis to remove rust from the gas tank?

    • Allard Vdhooft says:

      Yes, you can use alternative methods like using chemicals or abrasives to remove rust from the gas tank. Make sure to follow safety precautions and read the blog for detailed steps.

  12. Marshall Wood says:

    I appreciate the detailed explanation of how to clean the carburetor properly.

    • Allard Vdhooft says:

      Thank you, Marshall Wood! I’m glad you found the explanation helpful for cleaning your carburetor properly. Remember, keeping your fuel tank clean is essential for maintaining your lawnmower’s performance.

  13. Christian Arnold says:

    What are the signs that my lawnmower’s gas tank needs to be cleaned?

    • Allard Vdhooft says:

      To check for a dirty gas tank, look for trouble starting or running smoothly. Rust in the carburetor is a common sign. For cleaning steps, remove old gas, clean the carburetor, rinse the tank, inspect the fuel filter, & reattach the tank.

  14. Lori Long says:

    I feel more confident now in cleaning my lawnmower’s gas tank after reading this article.

    • Allard Vdhooft says:

      Thank you, Lori! I’m glad the article helped you feel more confident in cleaning your lawnmower’s gas tank. Happy mowing!

  15. Isaac Collins says:

    What are the best practices for storing a lawnmower with a clean gas tank?

    • Allard Vdhooft says:

      To keep your lawnmower’s gas tank clean, make sure to periodically rinse it with different techniques to remove rust and debris. Here are the steps to clean a rusty gas tank. Hope this helps!

  16. Teresa Hoffman says:

    Excellent step-by-step instructions on how to safely clean a rusty gas tank!

    • Allard Vdhooft says:

      Thank you, Teresa! I’m glad you found the instructions helpful for cleaning your gas tank. Let me know if you have any more questions!

  17. Terry Hale says:

    Great video resources shared for better understanding of the cleaning process.

    • Allard Vdhooft says:

      Thank you, Terry Hale! I’m glad you found the video resources helpful for understanding the cleaning process of a rusty lawnmower gas tank.

  18. Elsie Wallace says:

    Very useful tips on safely handling chemicals while cleaning the tank.

    • Allard Vdhooft says:

      Thank you, Elsie! I’m glad you found the tips on handling chemicals while cleaning the tank useful. Stay safe and happy cleaning!

  19. Myrtle Lawrence says:

    Are there any environmental concerns to be aware of when using chemicals or other methods to clean out a gas tank?

    • Allard Vdhooft says:

      Hi Myrtle Lawrence, when cleaning a gas tank, make sure to use the right methods to prevent harming the environment. Avoid spilling fuel or chemicals, dispose of waste properly, and consider using environmentally friendly cleaning products.

  20. Chris Freeman says:

    Can I clean the gas tank without removing it from the lawnmower?

    • Allard Vdhooft says:

      It’s recommended to remove the gas tank before cleaning to ensure a thorough job. This will allow you to access all areas of the tank and clean it properly.

  21. Kelly Adams says:

    I never knew about using vinegar to dissolve rust, thanks for the tip!

    • Allard Vdhooft says:

      Thank you, Kelly! I’m glad you found the tip about using vinegar to dissolve rust helpful. Let me know if you have any other questions or need more tips!