Dirt Bike Carburetor Cleaning & Adjustment

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Keeping your dirt bike’s carburetors clean and properly adjusted will ensure your bike can perform in top condition. 

It’s all part of keeping your bike it good condition. You can learn more here: How to Clean a Dirt Bike

Your carburetor plays a major role in how well or how poorly your dirt bike runs. 

If your dirt bike experiences issues while you ride, operate the throttle, or start it, it may be time for a carb cleaning. 

Symptoms of a dirt carburetor may include:

Use this guide along with MotorcycleZombies.com Carburetor Maintenance guides to get your bike back into peak condition. 

While you’re focused on your bike’s fuel/air circuit, it’s also a good time to learn how to clean the air filter on your dirt bike

If you ride frequently, keep your air filter clean, use a good fuel, and use a fuel treatment, you shouldn’t need to clean your carbs very often – maybe once every few years. 

However, if you’ve picked up a project bike or your dirt bike has been sitting for a while, you may need to clean the carburetor more frequently. 

How to Clean a Dirt Bike Carburetor

Before you get started, here’s what you’ll need to clean your dirt bike’s carb:

  • Carb cleaning solution (spray and dip).
  • Gloves and eye protection.
  • Clean rags/paper towels.
  • Flat head screwdriver and small socket wrenches.
  • Pliers. 
  • Replacement gaskets and jets, if necessary. 

First, you’ll need to remove the carb from the bike. Unscrew the clamps connecting the air box and the carb manifold. Unscrew the throttle cap and remove the throttle cable. 

You should now be able to remove the carb from the engine. 

Next, you’ll need to dismantle the carb, remove the floats, and unscrew all the jets.

Work carefully and keep the small components organized. 

Once everything is dismantled, you can start cleaning. 


For particularly dirty carbs, setting them in a carb cleaning dip solution for a few hours is often the most effective way to remove built up gunk and residue. 

You’ll need to clean all the metal parts, jets, and passages with a carb cleaning spray. (Don’t use carb cleaner on plastic or rubber parts).

You can use small carb cleaning wires to clear out any clogged jet holes. 

Once the carburetor is cleaned, dry it off completely with rags and compressed air. 

After that, you’ll be able to reassemble everything and put the carb back onto the bike. 

Continue reading for instructions on how to adjust the carb after it’s back on.  

How to Clean a Dirt Bike Carb without Taking it Off

Unfortunately, if your carb is dirty to the point where it is affecting your dirt bike’s performance, you will need to remove it in order to clean it properly. 

Leaving it on the bike usually will not solve the problem in most cases. 

However, you can minimize the need to removing the carb and cleaning it by:

  • Keeping the air filter clean.
  • Using an in-line fuel filter. 
  • Using quality fuel and a fuel treatment. 
  • Ride your bike frequently. 

How to Adjust a Dirt Bike Carburetor

After you clean and reassemble your carb, you’ll need to adjust it back to its proper settings. 

To adjust your dirt bike’s carb, you’ll need to:

  • Reinstall it onto the manifold and air filter. 
  • Install the throttle cable. 
  • Adjust the pilot screw by turning it about 1 to 1 ¼ turns out from seated
  • Adjust the throttle opening. 
  • Adjust the throttle’s free play by adjusting the throttle cable – start near with the adjustment near the carb body and finish with the adjustment near the throttle cable housing on the handlebars. 
  • Start the bike and make any necessary adjustments to the idle speed by making small adjustments to the pilot screw.

Further tuning can be achieved by:

  • Adjusting the clip position on the needle. 
  • Increasing or decreasing the main jet size. 

Check out some more of our carb tuning resources below. 

Refer to your bike’s service manual for exact adjustments for your carburetor. 

More Carb Tuning Resources

Looking for more information about cleaning, tuning, and adjusting your dirt bike’s carburetors? Check out some of these other free guides from MotorcycleZombies.com: