How to Clean a Carburetor?Step-by-Step Guide

Even as electronic fuel injection systems become mainstream, the carburetor, as a classic mechanical fuel metering device, remains a vital and valuable tool. Not only is it a milestone in the development of the internal combustion engine, but its irreplaceable reliability continues to make it widely used in motorcycles, small general-purpose engines, garden machinery, and classic cars.

What is a carburetor? 

A carburetor is a precision mechanical device responsible for "preparing a meal" for the engine. Its main task is to mix liquid gasoline and air, create a perfectly proportioned combustible mixture, and deliver it to the engine cylinders for combustion, thereby generating power.

What does a carburetor do?

When the engine piston descends on the intake stroke, air is drawn into the carburetor and flows through a constricted passage called the "throat" or "venturi." According to the principles of fluid mechanics, the airflow accelerates here, causing a significant drop in static pressure, creating a low-pressure area (vacuum) at the throat.

The carburetor has a float chamber at the bottom, which acts like a constant fuel reserve. The float works in conjunction with the needle valve to maintain a stable oil level within the chamber. When a vacuum is created in the throat, the pressure differential between it and the float chamber (which is usually open to the atmosphere) becomes the driving force for fuel flow. This pressure differential draws fuel out of the main jet and into the high-velocity airstream.

The drawn-in fuel and high-speed air collide and shear violently in the throat, initially atomizing. The mixture then flows through the throttle valve and into the intake manifold. During this process, the carburetor incorporates a complex oil circuit system consisting of an idle jet, main jet, air compensation jet, and enrichment device. This system enables precise and adaptive adjustment of mixture concentration and flow rate for various engine operating conditions, including idle, medium load, high load, and acceleration.

A thorough understanding of its operating principles is the cornerstone of high-performance commissioning and precise fault diagnosis.

Why should you clean your carburetor regularly? Benefits of a Clean Carburetor

A clean carburetor is important for several reasons. Most importantly:

• Restore Power: A clogged fuel orifice restricts fuel flow, resulting in a lean mixture (less fuel, more gas), preventing the engine from receiving enough fuel to generate its full power. After cleaning, the fuel supply is restored, and power returns naturally.

• Improve fuel economy: A dirty carburetor can cause an imbalance in the air-fuel mixture, most commonly a rich mixture (more fuel than air), resulting in fuel waste and incomplete combustion. Cleaning restores the air-fuel ratio to a precise level, ensuring every drop of fuel is fully burned, naturally improving efficiency.

• Extend engine life: A neglected carburetor can accelerate the deterioration of engine components and may even lead to early engine failure. Keeping your carburetor clean and regularly serviced ensures your engine operates smoothly and lasts as long as possible.

• Reduce maintenance costs: A carburetor that has not been functioning properly for a long time is like a ticking time bomb. The problems it can cause—such as severe carbon buildup, fouled spark plugs, or a clogged catalytic converter—often result in repair costs far greater than a simple cleaning and maintenance would have.
• Friendly to the environment: When the air-fuel mixture is too rich, a large amount of unburned hydrocarbons (HC) and carbon monoxide (CO) will be emitted. Keeping the carburetor clean and ensuring it operates in optimal condition is the most direct and effective way to reduce harmful gas emissions.

How to tell if your carb needs cleaning?

There are a number of warning signs that suggest your carburetor needs a thorough cleaning. The specific symptoms can vary depending on how severe the problem is, but you might notice the following issues:

• Hard Starting: If your engine is slow to start or fails to start altogether, a dirty carburetor may be preventing the right fuel-air mixture from reaching the combustion chamber. 
• Uneven or Rough Idling: When the carburetor is clogged, the engine may idle inconsistently, resulting in vibrations, frequent stalling, or even potential engine damage. 
• Loss of Power: Restricted airflow and fuel delivery due to build-up in the carburetor can make your engine sluggish and noticeably less powerful than usual. 
• Frequent Stalling: Especially at idle or low speeds, a dirty carburetor can cause your engine to stall unexpectedly. 
• Increased Fuel Consumption: If your engine is burning more fuel than normal, a clogged carburetor could be to blame, reducing overall efficiency and driving up operating costs. 

What should you look for in the best carburetor cleaner?

A quality carburetor cleaner must thoroughly eliminate the dirt and residue that accumulate within carburetors and related engine components. When choosing the right product, focus on options that deliver powerful cleaning performance to ensure your engine runs smoothly and efficiently:

• Fast and efficient: The best carburetor cleaners should act quickly to dissolve and remove stubborn deposits, making it easy to clean carburetors and related engine parts. 
• Safe for Carburetor Components: The best carburetor cleaners should be safe for all carburetor components—such as rubber, plastic, and unpainted metal—without causing any corrosion or damage. 
• Easy to use: The best carburetor cleaners should be user-friendly, ideally equipped with a spray nozzle or similar applicator that allows targeted application to problem areas, ensuring efficient and convenient use.
• International Certification: Including ISO9001 for quality, REACH for chemical safety, IATF16949 for automotive standards, ISO14001 for environmental responsibility, and ISO45001 for occupational health and safety.

Biaobang Carburetor Cleaner is an advanced, high-performance formulation engineered for rapid and thorough cleaning of carburetors. Its powerful solvents penetrate and break down persistent carbon, grease, and contaminants, restoring optimal airflow and fuel atomization, which are essential for peak engine efficiency and reliability. Additionally, Biaobang Carburetor Cleaner is available in a compliant, low-VOC version, meeting stringent regulatory requirements while maintaining exceptional cleaning performance.

How to clean the carburetor for a car?

If you want to do your job well, you must first sharpen your tools; sufficient tool preparation is the basic guarantee for the quality, efficiency, and safety of automobile maintenance.

Cleaning Tools and Materials List

1. Biaobang carburetor cleaner and compressed air are required to dissolve grease and clear the channels.
2. Basic hand tools like screwdrivers and socket wrenches are also needed.
3. A full carburetor repair kit (with all gaskets and seals) and a parts storage box are required.
4. Goggles and chemical-resistant gloves are required as safety precautions.
5. It is recommended that you utilize a camera to capture the state of the pipe connections before disassembly, since this is critical for a smooth restoration.

Step-by-Step Guide

1. Safety Preparations
   

   Disconnect the battery and drain the fuel.

   Take photos to document all fuel line and cable connections.

2. Disassembly
   Remove the air filter, disconnect all cables, and remove the carburetor.

   Open the float chamber and remove the float and ejector pin.

   Unscrew the main jet and idle jet (the most critical components).

3. Deep Cleaning
   

   Thoroughly spray all parts and passages with carburetor cleaner.

   Blow out all small holes with compressed air.

   Use a thin copper wire or toothpick to unclog the jets; do not use wire!

4. Reassembly and Installation
   

   Replace all gaskets (using a repair kit).

   Reassemble all parts in reverse order.

   Referring to the photos, reinstall the carburetor and connect all lines.

5. Commissioning
   

   Check for oil leaks.

   Start the engine and adjust the idle speed screw until the rpm is stable.

In short: Disassemble → Disassemble → Focus on cleaning the two jets → Replace all gaskets → Reassemble accurately. The operation requires patience and meticulousness.

How to clean a carburetor without removing it?

There are situations where you can clean the carburetor without needing to remove it from the vehicle. Provided the carburetor isn’t experiencing serious issues, you can follow the steps below to clean it while it remains in place.

Step-by-Step Guide

1. Preparation:

   Turn off the engine after it has reached operating temperature.

   Buy  Biaobang carburetor cleaner or fuel system cleaning additive.

2. Method 1: Fuel Additives (Simplest)

   Add the cleaning additive to the gasoline tank in the appropriate proportion.

   Fill the tank with gasoline and drive normally. The cleaner will circulate with the gasoline, dissolving contaminants.

3. Method 2: Intake Cleaning (more Direct)

   Remove the air filter to reveal the carburetor intake.

   Start the engine and maintain a constant rpm of around 1500.

   Insert the carburetor cleaner tube into the carburetor throat and spray it intermittently.

   Note: Apply small, frequent sprays to prevent staling or fuel slugging. This process should take approximately 5-10 minutes.

   
   

Important note: This approach is used for cleaning the main jet, oil tubes, and throats. It works less well on heavily clogged or fragile components (such as the idle jet). If the problem persists after cleaning, the carburetor should be disassembled and thoroughly cleaned.

How to clean carburetor on small engine?

Carburetor technology is still dominated by small, general-purpose gasoline engines. Instead of being used as vehicle propulsion systems, these engines are mainly used as mobile energy sources for different independent devices. These engines are frequently found in small agricultural machinery (like tillers and sprayers), construction equipment (such as vibrators, trowels, tiny generators, and water pumps), and garden equipment (like lawn mowers, chainsaws, and brush cutters). These gadgets must function in complex situations away from fixed power sources and are typically very cost-sensitive. Consequently, carburetors continue to be the most cost-effective and sensible option for their power systems due to their straightforward design, affordable cost, and ease of maintenance.

Step-by-Step Guide

1. Safety Preparation:
   Ensure the machine is stable and the engine is completely cool. 
   Remove the spark plug cap to prevent accidental starting.
   Work in a well-ventilated area, away from ignition sources.
   
2. Disassembling the Carburetor:
   Close the fuel valve. Remove the air filter housing.
   Disconnect the fuel line and throttle linkage.
   Loosen the retaining clamp and carefully remove the carburetor from the engine.
   
3. Disassembly and Cleaning:
   Remove the float chamber at the bottom of the carburetor.
   Remove the float and ejector valve.
   Locate and remove the main jet and idle jet (usually two brass screws with small holes). Clogged jets are the cause of most problems.
   Use a special carburetor cleaner and thoroughly spray all holes, passages, and jets. Clogged jets can be carefully unblocked with a very fine wire (such as a guitar string) or compressed air.
   
4. Reassembly and Installation:
   Reassemble all parts in reverse order. 
   Replace the gasket from the carburetor repair kit to ensure a tight seal. 
   Reinstall the carburetor, reconnecting all lines and linkages. 
   
5. Test:
   Open the fuel valve and replace the spark plug cap.
   Attempt to start the engine. After starting, you may need to readjust the idle speed and mixture ratio screws.

With these small engines, "prevention is better than cure." Ninety percent of carburetor problems can be avoided by using stabilizer and draining the fuel. When a problem does occur, cleaning the carburetor, especially those two small jets, can often give your machine a new lease of life.

How Often Should You Clean a Carburetor?

The optimal cleaning interval for a carburetor is influenced by multiple factors, including vehicle usage patterns, operational environment, and fuel quality. Industry best practices recommend servicing the carburetor at least annually or every 12,000 to 15,000 miles, whichever occurs first. If performance symptoms such as rough idling, hard starting, or loss of power are observed, more frequent cleaning may be warranted to maintain peak engine operation and prevent further issues.

How to Clean a Carburetor - All in all

Whether your ride is a roaring Harley, a rugged ATV, a cherished classic car, or a hardworking lawnmower or generator, if its engine relies on a carburetor, then regular carburetor cleaning isn’t an optional maintenance task—it’s an essential practice crucial to performance, longevity, and safety.