How to Prevent & Remove Motorcycle Exhaust Rust (Full Guide)


Rusty motorcycle exhaust can cause engine overheating. So preventing or removing rust is of paramount importance because the alternative is ugly appearance, more money spent on fuel and repairs.

How to remove motorcycle exhaust rust? To prevent rust clean the motorcycle exhaust and apply oil to it. To get rid of rust on a motorcycle exhaust, use a metal cleaner like Coca-Cola, a Chrome spray or follow the steps outlined in article.

Before we look into the process of preventing and getting rid of rust on motorcycle exhaust, lets briefly look at how an exhaust system work. This will help you understand why the following methods work.

Why a rusty exhaust is bad

Imagine the motorcycles exhaust system like a blowgun. If you have a leak in any sections of the plastic tube, you will not be able to send the small projectile very far. It will lose pressure and vacuum that are responsible for generating the force to shoot. Also, if there is an obstruction in the barrel, stone or other elements, the projectile would simply not exit.

In the case of the exhaust system, it is very similar: when the exhaust valves are opened, the piston pushes the gases towards the exhaust pipes, and these, when exiting, generate a vacuum effect that “pulls” the other gases, allowing them to leave.

Why a motorcycle exhaust gets rusty

There are two main causes of exhaust pipe rust: heat and water. Most times, water vapour condenses in the motorcycle exhaust when it cools down. You probably noticed water dripping from your motorcycle exhaust when you start your motorcycle in the morning.

When driving on wet grounds or in the rain, water is constantly splashed. However, you might say water also touches other parts of the motorcycle. However, the exhaust rusts faster. The reason is heat. The motorcycle exhaust is made of metal, and heated metals oxidize faster.

Corrosion Inside the Exhaust

Rust or corrosion inside metals (exhaust pipe) can be generated when a hole has been created in the exhaust which would not allow the correct removal of carbon dioxide gases. This also makes the metals develop tumour-like formations that grow larger until they block the exit of gaseous wastes, which can cause significant damage to the motorcycle engine.

Summary of the rust formation process:

  • The exhaust gases are extremely hot and corrosive.
  • Heat also causes condensation when gases come into contact with cold air, sometimes leaving water droplets on parts of the exhaust pipe.
  • This condensation is more of a problem if you only ride your motorcycle for short rides.
  • High temperatures are the main reason behind external rust mold, and water condensation is the cause of internal oxidation.

How to Check For Rust in Motorcycle Exhaust

Don’t let it get this far!

If the bike gradually loses power, yet the carburetor, cylinder and transmission work fine, then it’s time to check the exhaust pipe for any obstruction. Since oil is constantly burning in two-stroke engines, it is not surprising that sooner or later the exhaust pipe is clogged with carbon.

The reservoir can reach such a thickness that it will significantly reduce the diameter of the hole inside the exhaust pipe. The exhaust system will not be able to function to the prescribed standard, and the engine power will decrease.

The exhaust system of a motorcycle is especially vulnerable to corrosion, as it is exposed to a lot of moisture, heat, and other elements that cause oxidation.

Check For Obstruction

Check the exhaust pipe at least once every 5000 km. To check, you need to remove the exhaust pipe and blow into the exhaust pipe. If the air meets resistance the exhaust pipe is clogged.

Rust can be easily removed from the outside of an exhaust pipe, and the exhaust can be used as long as none of the oxides corrodes through the pipe.

If you have noticed rust stains on your motorcycle’s exhaust, you can use several simple methods to remove the rust. However, before we look into how to get rid of rust on motorcycle exhaust, let’s see how we can prevent rust.

How To Prevent Rust On Motorcycle Exhaust

The exhaust pipe and it is especially prone to rust. Since rust removal is not a pleasant task, it’s best to prevent rust before it begins to form by following these instructions:

  • Apply lubricating oil to the cooled exhaust pipe. The oil should be rubbed all over the pipe. It is also recommended to apply the lubrication oil weekly, especially during winter.
  • Keep your vehicle parked inside during winter or covered with protective material. This will prevent the salt content in the snow from melting and forming rust on the exhaust pipe.
  • Use a soft cloth to wipe moisture from rain or snow out of the exhaust pipe. The exhaust pipe should ideally be cleaned every day, to remove moisture.
  • Inspect the exhaust pipe daily for signs of rust. If you see a little rust, lightly sand the rust spots with super fine sandpaper.
  • Apply some wax paste after sanding the rust. Rub a cloth over the exhaust pipe to completely cover the pipe with the wax. It is essential that even the slightest oxidation is removed, to prevent it from spreading.

Use Machine Oil and Exhaust Cover

Some motorcycle exhausts have a part that is designed to be painted or covered with some kind of protective coating to stop rust from forming. The problem is that you might prefer the bare steel look (or don’t have a coating option), but you don’t want to deal with scrubbing the rust often.

An affordable alternative will give you all the look and style that comes with bare steel, without any of the rust problems; it just involves a little oil.

Note: You need to get an exhaust cover to protect the oil from being washed out by high-velocity water or rain.

Step-by-step guide:

  • Clean the surface of the item you want to prevent rust on by using a degreaser and a rag. Make sure the exhaust is completely clean before applying the oil.
  • Apply machine oil to the motorcycle exhaust surfaces by pouring it onto a shop towel and rubbing all of the parts.
  • Rub the machine oil everywhere on the motorcycle exhaust. As you do so, the steel will turn a slightly darker shade, showing that the part is saturated with oil. If you see a dry spot, go back and reapply.
  • Wipe off all excess machine oil using a clean rag. This will make the surface as dry as possible and will not leave an oily residue on anything that you put on it.
  • Discard the rags and keep them away from a heat source.

Warning:

  • Oil soaked rags can catch fire quite easily. Put them in a metal garbage container, if possible; at the very least, keep them away from any source of heat.

Conclusion: Preventing Exhaust From Rusting

First, you need to keep your motorcycle exhaust clean. Your motorcycle exhaust needs to be regularly checked and cleaned to ensure that rust doesn’t form overnight.

Most people complain about oil causing more rust on motorcycle exhausts than actually preventing it. However, they are missing the point: The applied oil protects the motorcycle exhaust against moisture, and the exhaust cover protects the oil from being washed away. By applying these two ideas together the rust stands little chance of forming on the exhaust.

How To Remove Rust From Motorcycle Exhaust

When the exhaust pipe is too dirty, the motorcycle consumes more fuel and the engine strains. This effort ends up wearing down the engine and decreasing the performance of the motorcycle. And vice-versa, maintaining a good level of cleanliness in the exhaust pipe will help keep your motorcycle in top shape, and it’s better for your health and the environment.

Things you will need:

  • Caustic soda
  • Hot water
  • Pressure hose
  • Screwdriver

Instructions For Cleaning The Motorcycle’s Exhaust Pipe

Begin By Removing The Exhaust Pipe: In order to clean the pipe, remove it from the motorcycle’s exhaust system. We can take advantage of this clearing to clean the spout as well. We will only need a brush with strong bristles that can help us remove the residues.

Unscrew The Muffler From The Bike: Remove the tube completely. Begin by disassembling it using a screwdriver. We must do this with relative caution.

Take Special Care When You Disassemble The Pieces: If you do this in a very rough way or with tools that are not of adequate size, you could end up damaging the parts. Usually a number 12 socket can be used to disassemble the end of the tube.

Remove The Packing From The Exhaust: It needs to be removed to clean the entrance.

Once you’ve carefully removed the tube, it’s time to close the bottom of the tube. Then you can add a cleaning solution inside the tube.

Add Caustic Soda And Hot Water: It is best that you do this by wearing gloves that can protect you from the chemicals, also wear a face mask to avoid breathing in toxic fumes. Avoid skin contact with this solution as much as possible.

Let The Solution Sit And Allow It To Take Effect: This should sit for 10-15 minutes to provide a good cleaning effect.

Afterwards, remove the residues by emptying the tube. Be careful that none of the residue touches your skin. Make sure this goes straight to the drain.

With The Hose, Apply Water Under Pressure With The Tube Uncovered: We apply water to remove excess residue because although the exhaust pipe material is resistant, caustic soda is highly corrosive and can damage the metal. As if that were not enough, breathing soda residue when the motorcycle is hot could be harmful.

Leave the exhaust parts to dry before assembling them back on the motorcycle.

Here’s a helpful video tutorial for cleaning the exhaust faster:

Tips For Cleaning The Motorcycle Exhaust Pipe

Don’t Use Scourer

One of the main mistakes most people make when trying to get rid of the rust that has formed on the bike is using a scourer. It is possible that by rubbing hard you will be able to remove the rust, but it is also very possible that you will scratch the outside of the motorcycle, and keep in mind that there is no going back after that.

Otherwise, we recommend that you use a cloth rag or a sponge. Although you may have to try a little harder to remove the rust, you will ensure that the motorcycle does not suffer any damage.

Use A Quality Metal Cleaner

Your best ally will be a specific metal cleaner, applying it in those areas where rust is present. However, you can also take advantage of it to do general cleaning of the rest of the metal areas of the motorcycle.

Coca-Cola, A Great Metal Cleaner

You would be surprised at how effective Coca-Cola can be when it comes to removing rust, to the point that many motorcycle owners use it regularly. It contains phosphoric acid, which can remove rust from all types of metals.

Another product that would surprise you by its effectiveness is vinegar, which contains acetic acid and is almost as effective as Coca – Cola.

Use A Chrome Spray

If you want your motorcycle to look perfect, we recommend that after finishing with the rust you apply a specific spray for chrome, which will make it possible for your motorcycle to look extra fresh.

What If The Rust Doesn’t Disappear?

If these solutions don’t work for you, the last resort is to use sandpaper. The rust will disappear if you remove it forcefully with sandpaper, but the exhaust might also suffer visible damage. So if you opt for this solution, we recommend that you later paint the area to cover the damage.

Summary: Cleaning Motorcycle Exhaust

Detergent and similar cleaners often do not remove or thoroughly remove rust, so the best option is to use caustic soda. However, if you think that this product is too aggressive, opt for a pro cleaner instead.

Also, for safety reasons, it’s recommended to change the packing/cover of the exhaust every time you clean.

Final Words

Keeping a motorcycle in top condition requires some basic regular maintenance and cleaning. Luckily, rust removal is not a complicated or difficult procedure. There are several ways to go about it, and each method uses readily available supplies.

If the exhaust is badly rusted, consider changing the exhaust. A badly rusted exhaust pipe does not work as designed, and it allows harmful gases into the air.

By implementing these tips, I’m confident you will be able to make your motorcycle exhaust rust-free and keep it that way in the long run.

Luka Barron

Motorcycle mechanic, writer and Heineken lover. A bit like Hank Moody on a Suzuki.

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