Dirt Bike Flooded? Here’s the Best Way to Fix It

There are many possible reasons why your dirt bike won’t start, so the first thing you need to ask yourself is: “how do you tell if a dirt bike is flooded?”. Only after you’ve correctly determined the problem, can you fix it. But do not worry, I am here as an experienced off-roader to give you a complete guide to flooded dirt bikes, from diagnosis to fixing.

As a general rule, you can tell that your engine is flooded when your dirt bike isn’t starting and you feel a faint smell of fuel. In order to make sure this is in fact the issue, you need to remove the spark plug and examine it. If the spark plug is wet, then you can be certain that your dirt bike is flooded.

To fix this issue, start by drying off the spark plug with a towel. Turn the choke and gas line off, then lean the bike to the side so that the excess fuel can evaporate easier. Kick start the dirt bike for 5 times or so to dry the compression cylinders. The last step is to put the dry spark plug back and turn the gas back on.

Unflooding your dirt bike’s engine is not a difficult task, but it needs to be done correctly. I will now expand on these steps so that you can be certain you are doing it right. Keep on reading to learn all about flooded engines and discover an even quicker alternative method to fix this issue for 2 stroke dirt bikes.

How Do You Tell If a Dirt Bike is Flooded?

muddy dirt bike

I will repeat myself once again: there are quite a few reasons why your dirt bike won’t start, and flooding is not always the first thing you would think about. However, this is quite a frequent occurrence for regular riders, so knowing how to spot it is essential information. Personally, I am a practical guy and I like to understand the process behind an issue before I do any troubleshooting.

If you are similar to me, then you will definitely appreciate learning the reason behind why a dirt bike engine gets flooded. The culprit is almost always the spark plug, but a dirty air filter is a frequent cause of this issue as well. When your spark plug doesn’t produce the necessary spark to create combustion, the carburetor keeps sending more fuel into the cylinder with each kick start. This causes, quite literally, flooding of your cylinder and renders your dirt bike unusable.

In some cases, the spark plug is actually completely fine and the issue starts from a dirty air filter. When the air filter is not working properly, not enough air gets into the engine, making the combustion process impossible. If you haven’t checked your air filter in a while, then it’s time for a cleaning ASAP. A little engine flooding that can be fixed in less than an hour is the least of your worries when you have a dirty air filter!

Right from the gecko, you can tell that your bike is prone to flooding if you know your spark plug needs changing or your air filter is full of dust. Another easy-to-spot sign of this issue is a faint (or sometimes strong) smell of fuel. Nevertheless, you can tell for sure your dirt bike was flooded when you remove the spark plug and you see it covered in oil.

How Do You Unflood a Dirt Bike?

When you are positive that your engine is flooded, here are the five steps that I recommend you take:

1. Dry off the spark plug

After removing the spark plug, use a towel or an air compressor to remove the fuel. Leave it in the sun for an additional 10 to 15 minutes to evaporate any remaining residue.

2. Turn off the choke and the gas line

This way, you will allow more air to enter the engine when you kick start it.

3. Lay the bike slightly on its side

This allows excess fuel to drain off if your bike is severely flooded. It also ensures better airflow and faster evaporation of the fuel. Let the bike sit like this for at least 15 minutes.

4. Kick start the bike a few times

Without adding the spark plug, you can kick start the dirt bike 5 or more times to dry off the compression cylinders.

5. Add in the spark plug and give it another kick

After your spark plug has completely dried off, put it back in and kick start your bike again. If the engine still doesn’t start, then it’s probably a sign that you need to change your spark plug.

How do you start a 2 stroke flooded dirt bike?

determine if dirt bike is flooded

If your 2 stroke dirt bike won’t start, you can use an even simpler method of unflooding your engine that has been a lifesaver for me on more than a few occasions. You start out by switching off the petcock valve, in order to reduce the fuel in the carburetor and push in more air into the engine. Kick the bike on WOT (wide open throttle) to lean the fuel mixture and get the motor started. This two-step method works like a charm for most 2 stroke dirt bikes, so I highly recommend it.

Keep in mind that if your dirt bike is too flooded, this quick method will not work. If you try out this technique and it doesn’t make your engine start, it’s best to stick to the five steps I’ve explained earlier. These work just as well for a 2 stroke dirt bike and should solve your flooding. In case neither of these methods works for you, then you might have another problem.

Are you planning to buy a second hard dirt bike? If yes, you might want to check out the article I wrote on how to determine the best mileage for second hand dirt bikes.

What Can Cause a Dirt Bike Not to Start?

Flooding is not uncommon, and most avid dirt bike riders will encounter this issue at least once in their lifetime. But what happens if you try fixing it and your engine still won’t start? Well, there are four factors that influence combustion: air, fuel, compression, and spark. If fuel mixture is not the issue, then you might be dealing with a dirty air filter, little to no compression, or a faulty spark plug.

Here’s a video guide (verified by yours truly) on how to check your dirt bike when the engine won’t start:

Bob Kelly

Hey there, my name is Bob and I've been riding ATVs, dirt bikes, and UTVs for most of my life. Going on outdoor adventures has always been my passion. I love sharing tips and tricks with beginners who are getting ready to join the world of outdoor enthusiasts. You can reach me at bobtheatvguy@gmail.com if you want to get in touch.

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