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How to Prevent Rust Buildup in a Fuel Tank

How to Prevent Rust Buildup in a Fuel Tank

Modern motorcycles are fitted with plastic fuel tanks, making them lightweight and rust-free. However, most motorcycle fuel tanks are made of metal, with rust forming inside them over time. Rust buildup in a motorcycle fuel tank can degrade the fuel quality and affect a motorcycle’s performance. Rust can mix with the fuel and enter the fuel delivery system, affecting fuel consumption.


The motorcycle can also stall during a ride due to running on contaminated fuel.


Cleaning the motorcycle properly including the engine, fuel injectors, and fuel tanks is essential as it helps improve your motorcycle’s look and performance.


Read this article to learn how to prevent rust buildup in a fuel tank.

1. Reasons Why Rust Develops Inside the Motorcycle Fuel Tank

All types of fuel contain small traces of water that causes the metal in the fuel tank to oxidize over time as the water gradually starts to settle at the bottom of the fuel tank. The process of water-fuel separation speeds up when the motorcycle is not used for a long period.


Water settles in the fuel tank due to being denser than fuel. Fuel starts reacting to the metal due to the presence of water, which initiates rusting.


When you turn on a motorcycle after a long period, the water accumulated at the bottom of the fuel tank enters the engine and makes it difficult to initiate combustion.


Seasonal riders who ride their motorcycles occasionally may encounter this issue more often than riders who ride regularly.


Water can also enter the fuel tank when the motorcycle is washed. Before washing or cleaning the motorcycle, make sure that the fuel tank cap is completely closed and the lid is covered to prevent water from entering the fuel tank.


When cleaning the fuel tank from the inside, make sure to dry it completely before reinstalling it. Do not turn on the motorcycle until the fuel tank is completely dry.


Rusting in the fuel tank will speed up in humid conditions.

2. How to Prevent Rust Buildup in a Fuel Tank

Rust buildup in a fuel tank can be prevented if you maintain your motorcycle’s fuel tank regularly.

2.1 Keep Your Motorcycle’s Fuel Tank Filled Up

The small traces of water in the fuel will start to evaporate due to the difference in the interior and exterior temperatures of the fuel tank. The evaporated water then condenses to become a liquid that separates from the fuel until it accumulates at the bottom. If you keep your tank filled up with good-quality fuel, it leaves no space for condensation to occur and prevents rusting.

2.2 Use High-Octane Fuel

High-octane fuel has a lower alcohol content which reduces water contaminating the fuel. Alcohol in the fuel traps water droplets, promoting rusting inside the fuel tank.


The quality of fuel available at different fuel stations can also differ depending on their storage conditions. Make sure to refuel your fuel tank from trustworthy fuel stations.

2.3 Ride Your Motorcycle Regularly

If the same fuel settles in the fuel tank for a long period, rust can start to form inside. When you ride your motorcycle regularly, it ensures a continuous flow of fuel through the fuel pump, fuel lines, carburetors, fuel injectors, and combustion chamber. If you are a casual rider, ride your motorcycle at least once per week.

2.4 Drain the Fuel Tank Completely While Storing the Motorcycle

If you have to store your motorcycle for a long period, make sure to drain the fuel tank completely as the fuel quality will degrade over time. After draining the fuel tank, give it some time to air-dry. To get rid of all the small water droplets, place silica gel packets inside the fuel tank. Removing the fuel tank and sealing it completely before storing the motorcycle can also help prevent rust buildup inside the fuel tank.

2.5 Adding Fuel Stabilizer to the Fuel

Fuel stabilizer is a chemical additive that strengthens the bond of the fuel molecules. It is mostly used by riders before they store their motorcycle for long periods since it helps prevent the petrol from breaking down and water from evaporating and undergoing condensation.

3. What to Do If Rust Forms Inside the Fuel Tank

  • If you see rust building up inside the fuel tank, it is time to properly clean it. You will need to remove the fuel tank before filling it with half a liter of distilled water and adding the same amount of pure sand. Shake and rinse the fuel tank and let the mixture remove the rust completely.
  • Another safe way to remove rust inside the fuel tank is by using baking soda and vinegar. Wait for some time until the mixture starts to change color and bubbles start forming due to reacting with the rust. Shake and rinse the fuel tank well to remove rust flakes completely.
  • There are also several rust-removing products available in the market.
    These products are highly effective but require handling with care since they contain chemicals.

4. Frequently Asked Questions (FAQs)

4.1 Can Rust in the Fuel Tank Damage the Engine?

Rust inside the fuel tank can degrade fuel efficiency and performance but can also damage the engine. It can clog the fuel filter, fuel pump, and fuel lines which can disrupt fuel flow. In severe cases, it can completely cut off fuel flow and cause the engine to malfunction.

4.2 What Chemical Can Break Down Rust?

Strong acids, including phosphoric acid, sulfuric acid, and hydrochloric acid (also known as muriatic acid in its diluted form), break down rust but can also react with the finish, paint, and metal.

5. Final Words

Rust forming inside the motorcycle fuel tank can degrade performance, fuel quality, and fuel consumption. There are several ways to remove rust formed inside the fuel tank, including wet sanding and chemicals. However, every rider should learn how to prevent rust buildup inside a fuel tank. By riding your motorcycle regularly, draining the fuel tank completely during storage, and keeping your motorcycle fuel tank filled with high-octane fuel, you can prevent rust from forming inside the fuel tank.


A clean and well-maintained motorcycle has better-holding value. If you are looking for high-quality aftermarket parts to make your motorcycle look good and perform better, Viking Bags offer sissy bars, crash bars, fairings, handlebars, and backrests. If you love motorcycle touring, you can choose from a wide range of luggage options available at Viking Bags, including saddlebags, sissy bar bags, and handlebar bags.

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