How to Clean a Carburetor on a Dirt Bike

Guide to Dirt Bike Carb Cleaning

Dirt bike carburetors keep motorcycles working at their peak condition. Riders should keep their bike carburets clean because a dirty carburetor hinders the efficient performance of the bike.

Besides, significantly dirty carburetors can prevent your dirt bike from starting or functioning at all. When maintaining your bike, spare some time to clean your carburetor.

Sometimes carburetors can get extremely dirty, making it difficult for you to clean. Many brands also design complicated carburetors, which prove hard and tiring to maintain. Regardless of their intricate designs, you shouldn’t feel intimidated when cleaning carburetors.

However, always ensure that you follow the right steps to clean and maintain your dirt bike’s mechanical parts. Before disassembling your carburetor, gather the right set of tools that will help you in unbolting and unscrewing the machine.

You should unbolt the carburetor with extreme care because every delicate part can suffer severe damage if mishandled.

In this paper, we discuss the different safest ways to clean your carburetor, the right tools to use, and additional safety precautions you ought to take when maintaining the essential parts of your bike.

Which tools do you need to clean your carburetor?

Before anything else, consider safety your first tool when cleaning carburetors. The carburetor contains and emits harmful gasoline compounds that can cause skin irritation and other health complications if inhaled.

Put on safety gloves and goggles throughout the cleaning exercise to protect the most critical parts of your body. After safely dressing up, ensure you clean your working location and its surroundings. Also, include proper lighting in the area to see clearly.

We advise riders to keep their working areas clean because dirt bike maintenance calls for adherence to high hygienic standards. Carburetors especially necessitate the observance of higher cleanliness standards than any other dirt bike machine.

You should include the following tools when undertaking the cleaning routine:

  • Socket wrench
  • Compressed air
  • Wrenches
  • Screwdrivers
  • Thread lockers (low and medium strength)
  • Gloves
  • Hex keys
  • Carburetor cleaners
  • Cleaning rags
  • Service manual

Before conducting the cleaning exercise, make sure that you first refer to your service manual before collecting other tools.

Service manuals indicate the right procedure to follow when operating different carburetors because manufacturers design models differently. It would be best if you stuck to the service manual provided by your dirt bike manufacturer and not consult any other guide.

A service guide shows you the significant differences in proper cleaning and fully outlines the different tool types and sizes you’ll need for your cleaning.

You can quickly find all your tools at the regional motor dealer. However, many dirt bike owners find it extremely difficult to find condensed industrial air.

Riders should visit retail stores around their locality for nonindustrial alternatives sold and stored in pressurized cans and at affordable prices.

You should purchase new screwdrivers because you’ll need them to remove brass spouts. If a screwdriver misses the exact location of a brass jet, it may easily destroy them.

You’ll need other necessary tools, including flat-blade screwdrivers, crosshead, scaled socket set, metric, carburetor cleaners, and steel rules.

How to remove your carburetor from the dirt bike

Most manufacturers use a pair of bolts or round clamps to keep the carburetor within the bike’s mechanical design.

We recommend bikers to stop the main fuel supply before pulling out the carburetor. Use a hose to drain the float cavity by connecting it to the small screw beneath the float chamber.

In many dirt bikes, removing the control cables and slides takes less time and effort after detaching the bike’s carburetor from the engine.

Some part of your disassembly will involve detaching the float chamber from the carburetor. To remove the section, turn the carburetor until the upper side faces downward to identify the bolts holding the float section in place.

Some chambers feature wire clips for tightening, while other units come with three bolts. After unscrewing the compartment, ensure your tap with the screwdriver’s handle can remain stable for a long time and proceed to unfix the chamber from its gasket.

You should see the pilot jet (primary jet), jets, and main floats immediately after unscrewing the float chamber from the carburetor. Ensure that you remove the floats before continuing with unbolting because of the floats’ delicate nature.

Most dirt bikes come with brass or plastic floats. Plastic floats easily leak, so inspect them to see if they hold any fuel before checking the jets.

The floats of Mikuni and Keihin carburetors should rotate without friction on their pressed-in pins. When detaching the pins from the floats, ensure that you observe extreme caution because the aluminum stands that hold the plugs tend to bend or break easily under pressure.

When unscrewing the pin with a tap, hold it in one direction.

Most bike carburetors come with two-jet structures. The first spout controls gasoline flow from the empty to the one-third asphyxiate valves while the other jet regulates fuel flow to the two-thirds throttle valves.

Jets often get blocked because of their narrow sizes. A blocked jet can significantly hamper the opening of the throttle openings and result in poor carburetor performance.

Dirt bikes can only overcome the blockage problem by creating a significant throttle to unblock the passages. Fixing the problem also involves the replacement or thorough cleaning of the old jets.

Aside from the jets, you should remove the air and fuel adjusting screws when cleaning carburetors. Carefully examine the screws’ position in connection to the slide to determine their types.

Air adjusting screws remain fixed beside the air filters, while fuel adjusting screws stay bolted on the bike engine’s side. The tapered or pointed screw significantly affects the medley strength – support or scope – in the choke aperture’s first tierce and functions alongside the primary jet.

You should always note the sharp pin’s position before unscrewing it because manufacturers fix the screw at a few spins from its tightly closed turn. You should return the screw to its original place when reassembling the carburetor.

Steps to follow when cleaning the carburetor

  • Thoroughly clean the float base using recommended carburetor cleaners and clean rags.
  • After cleaning the bowl, check other carburetor parts for dirt.
  • Wash out all the openings on the carburetor’s body with carburetor cleaners and subsequently blow condensed air through the holes.

Ensure that you keep your safety goggles when blowing and washing the carburetor because the machine contains dirty particles and harmful fluids that may enter and destroy your eyes if left unprotected.

Reinstalling the carburetor

It would help if you reassembled your carburetor correctly by following the reverse disassembly procedures. However, it would be best if you inspected the float acmes before reinstalling the float cavity.

An altered float height will most likely affect the overall functionality of the mixture and engine. Riders can regulate the measurements by twisting the metallic tangs. Bending the tang exerts a slight pressure on the motor’s needle opening.

You might cut off the gasoline inlet into the float chamber and affect the fuel height, so don’t twist the tang too much.

The maintenance manual will indicate the right fuel height, which manufacturers, with the aid of a ruler, determine by observing how the inverted carburetor positions from the gasket top to the floats’ peaks.

We recommend riders to fine-adjust their adjusting screws every time they reinstall their dirt bike carburetors. After reattaching the carburetor as instructed by the service manual, start the bike engine and leave the motor to warm up until it achieves its normal functioning temperature.

Regulate the screw position in quarter-turn rotations. A speeding engine will indicate optimum functionality and adjustment, while a slower machine will necessitate tighter adjustment.

Why should you clean dirt bike carburetors?

Clean carburetors keep dirt bikes in optimum functioning condition. Dirty carburetors require a lot of energy to power up and thus may degrade the engine. In extreme circumstances, contaminated carburetors can halt engine performance.

It would help if you immediately cleaned the carburetor when your dirt bike engine stops working. A carburetor comprises numerous challenging parts.

However, it would be best if you didn’t suffer any intimidation when cleaning the motor because a service manual and the right equipment will guarantee a successful cleaning, disassembly, and assembly process.

How will I know that my carburetor requires cleaning?

Healthy hearts will keep you alive and strong for ages to come. A healthy carburetor keeps the dirt bike in perfect working condition and warrants prolonged engine life.

Contaminants such as cholesterol can severely affect and damage the heart. If the carburetor carries a mixture of dirt and sticky gasoline residue in the float chamber, the engine will flunk easily, and your bike will most likely fail to start and run.

Riders should keep their carburetors clean at all times if they want their dirt bikes to run efficiently. The following signs will indicate that the carburetor requires cleaning:

  • The engine won’t start

If your engine produces a cranky noise during ignition but fails to start, your carburetor might contain a lot of dirt. Accumulated dirt in the carburetor prevents the realization of proper air and fuel combination.

Fuel in a dirty carburetor can’t reach the engine, resulting in repeated turnovers with no actual start.

  • The engine runs lean

A lean engine will occur when the balance of fuel and air gets thrown off-balance. The gasoline to air ratio shouldn’t surpass 1:15 or 1:12.

An excessively high or low amount of fuel or air will cause sneezy or popping noises in the course of intake. Engines often run lean when little gasoline arrives at the carburetor.

  • The engine runs rich

Motors that run rich suggest that the carburetors contain excessive fuel amounts in insufficient air levels. Engines often produce black smoke during the incomplete mixing of air and fuel in the carburetor.

  • A flooded engine

A lot of dirt and debris within the carburetors’ fuel bowls can clog the needle valves and prevent them from closing. When the needle valve closes, fuel levels increase within the cavity and thus overflow, and make the spark plugs wet.

While you shouldn’t blame the carburetor for most of your dirt bike complications, knowing and observing the different underperformance signs will help you identify if the faulty carburetor caused the problem.

How hard can cleaning the carburetor get?

Some dirt bike brands design simple engines, while others build complex ones. Generally, cleaning a carburetor shouldn’t cost you a lot of mental and physical effort, mainly if you learned a thing or two concerning dirt bike mechanical parts.

Taking your bike for a carburetor checkup to a mechanic or shop will cost you lots of cash. It would be best if you trained and learned to clean and repair your motorcycle carburetor because it would save you many repair costs in the long-run.

How regularly should you clean your carburetor?

It often gets confusing for dirt bike riders when they fail to know precisely the right times to run full-scale maintenance on their carburetors.

We advise riders to clean their carburetors once after two years. However, different motorcycle owners prefer to clean their engines depending on demand; some will clean them twice a year, and others only once.

Owners who rarely ride their bikes should clean them more frequently than those who often ride their bikes. When left unused for a long time, dirt bike carburetors tend to accumulate a lot of grime and dirt, making it critical for owners to clean them every once in a while.

Motorcyclists can use fuel filters to keep carburetors clean because they work exceedingly well in trapping tiny particles that the petcock and screens in the carburetor fail to catch.

Also, always ensure that you flush out the premixed gasoline because more sediments will likely accumulate in the carburetor if the rider uses pump gasoline.

The benefits of using WD40 cleaners

The strong cleaning power of WD40 cleaners will wash off grime, oil, and other resistant carbon residues. You can use the solvent-based agent to clean non-painted metallic sections, the throttle frame as well as the carburetor.

The dual-action functionality of the cleaner works by breaking down the dirt inside the carburetor.

The cleaner subsequently blasts the dirt with its effective spray to eliminate all residues. Cleaning your dirt bike parts with WD40 guarantees an efficient motor that starts quickly and runs consistently and powerfully.


Fuel and air mix in the carburetor before flowing into the motor. Sometimes the gases and fuels don’t mix properly, resulting in sticky linings on the carburetor walls that enlarge with time.

Cleaning your carburetor will eliminate all residues and guarantee the engine’s maximum performance.

Before cleaning the carburetor, remove all plastic and rubber parts because the cleaning agents may damage them. Also, ensure that you replace the gasoline in the fuel tank before starting the engine, or else your carburetor will experience the same problems.

If you keep your carburetor clean, you will enjoy better engine performance and save yourself the extra cost of replacing a worn-out engine if the problems pile up.

You can carry out the easy cleaning process by reading the manufacturer’s manual and using the right tools to disassemble and reassemble your carburetor carefully.