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How To Clean A Dirt Bike Motor (Degreasing & Deep Cleaning)


Cleaning a dirt bike motor correctly.

When it comes to keeping your sweet ride clean, it can be easy to forget the engine. You likely spend some time rinsing off the seat and maybe the front if the dust is unusually thick, but many people forget that when an engine is dirty, it can impact the way your bike runs. No one wants to deal with a bad motor, so you should remember to clean it regularly. 

The easiest method to clean a dirt bike motor is to: 

  • Zip-tie plastic bags around orifices 
  • Spritz the motor with degreasing solvents
  • Use water and dish soap on a rag to gently wipe down the motor by hand.

If you have been wondering how to clean a dirt bike motor without wasting an entire afternoon, we will shed some light on the most painless cleaning method. You will not have to worry about being intricately thorough or anal about your cleaning, but it is essential to take pride in your bike and its inner workings by keeping them shiny and well-oiled.

How To Clean A Dirt Bike Motor

You will need special cleaners for your motor. Plain water can damage your engine if you try spraying that everywhere so we do not recommend simply taking a wet rag and going at it. Additionally, depending on how long it has been since the last time you cleaned it, you might need some extra cleaning power to cut through the grease and remove everything.

Many people swear by Scotch-Brite pads for getting a real deep clean. You will need to tape everything off and bolt in the clutch cylinder so that the cleaning process does not disturb any of the motor’s mechanical insides or allow any water to get inside. As a machine, you will need to be careful about where you put the water and cleaner to keep everything running smoothly.

Plenty of people spray down the motor with their cleaner of choice, or simple dish soap, before hosing down or handwashing the engine to break down the dirt and grease coating it. If you do not want to spend hours breaking your back scrubbing endlessly at that one spot, use some soap or cleaner to do the hard part first.

Then, once you have entirely rinsed it, you can use a brush or pad to rub it down and get anything that the soap and water missed. Remember to be careful with the water not to get any inside of the motor during the process. Pretty soon, your engine will be looking as shiny and chrome as it was when you first bought your bike. 

This YouTuber walks through the process of cleaning a dirt bike engine with a degreaser:

How to degrease a dirtbike engine!

Should You Remove The Engine Before Cleaning It?

If you are looking to do a true deep cleaning, it is recommended to remove the engine from the bike during cleaning for several reasons. First of all, power washing your bike and cleaning the machine are two very different processes. If you forget to remove the engine before hosing down your bike and you have opened the engine compartment, there is a high chance that you will get water where it should not go.

Hosing down a bike regularly right after use is always recommended, but the bike’s guts are a little more sensitive and require more TLC than the rest. Having the engine separate from the bike allows you to get in all of the nooks and crannies and seal off the openings once again and stop the water from getting inside.

When the engine is out of the bike, you can also access the inside of the compartment where the engine sits. Washing that part of the bike out, too, is not a bad idea either. When you wash the engine, take the opportunity to do all of the minor fixes and tightenings for your bike that you usually neglect or forget about. 

Did we mention how important it is that water does not get inside? It is critical if you do not want to slow your roll! The same thing goes for the soap or cleaner and anything else you might be using to polish up the engine. Removing a bike engine is not difficult or time-consuming. It merely requires a little bit of elbow grease.

Watch this YouTube video for an excellent demonstration of cleaning an engine that’s been removed.

How to Wash Your Dirt Bike Engine

How To Remove A Bike Engine

The absolute first thing to do is make sure that you have the help you need. The hardest part of getting an engine out of a dirtbike is knowing that it can easily weigh over 80 lbs. If you are worried about lifting that weight, ask a friend to come, give you a hand. Once you have established that aspect, it is time to prep the bike to have its motor removed.

Prepping the bike includes:

  • Draining the oil
  • Removing the bodywork
  • Mounting the bike on a stand
  • Removing the carburetor
  • Disconnecting electrical cables and hoses

You should put a bowl or pan underneath the bike to let the oil drain out before removal. After the oil is out, you can set the bike on a service stand to hold it steady while you work. You will need to take off the bodywork, subframe, and gas tank to reach the engine. Many motocross bikes let you take off everything at once, which is handy. 

Usually, it is better to clean as you go, not to end up putting a clean engine into a dirty dirt bike. You will also need to remove the carburetor before taking the engine out. This provides an excellent opportunity to clean the carburetor as well, which many people take advantage of. You will need to cap up the fuel opening so that it is not contaminated while out.

There will likely be hoses or cables that need to be disconnected before you can finally remove the engine from the bike chassis, but once you have, you will need to actually put in the effort of lifting the engine out and setting it to the side. If your bike is on the smaller side, this may not be as heavy or difficult, but you should be careful nonetheless. 

This YouTuber really takes the time to walk you through each step of the process and he’s got some handy tips along the way:

How to remove the motor from a dirt bike Part 1 (2007 RM125)

How Often Do You Need To Clean A Motor?

For motocross bikes, you might not notice as much of a build-up when it comes to dirt, rust, and grease, but for off-road bikes, the dirt can pile up quickly. Generally, it is recommended to perform a deep and thorough clean of your dirt bike motor at least once a year, possibly more often if you frequently take it off the beaten path.

Some people make the mistake of washing their motor too frequently, which is not typically recommended. You should always try to get away with the least amount of polishing and buffing as possible so that you do not wear down the metal or accidentally damage the engine in your quest for the ultimate clean machine. 

Once in a while, if you want to get fancy with your yearly cleans, you can use a tool for cross-buffing, which is a type of cleaning using high-pressure air blown through a small opening to give your motor that extra bit of shine it needs before you put it back inside your bike. However, you should not do this very often because it wears away the metal.

In Summary

If you want your bike to look as awesome as the day you first brought it home, you will need to remember to give your motor at least a once yearly wash. The process of removing it from the bike, spritzing it with a cleanser, and then carefully rinsing it off is quick and easy. You will finish it up early enough in the afternoon to catch your favorite game on TV afterward. 

Teddy Henderson

Teddy is always fiddling with small engines, picking up thrown-out string trimmers or tearing apart dirt bikes. He shares what he learns along the way. Hopefully, you'll have less headaches than he has had by learning from his mistakes.

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