How to Adjust a Carburetor

A carburetor is a crucial part of any car's engine. The carburetor is used to mix gas and air together, aiding the combustion process. Parts of a carburetor can become contaminated by all kinds of environmental filth, such as dirt, grass or even small sticks. It's important for a car owner to clean and adjust a carburetors regularly to ensure the engine functions as efficiently as possible.

Instructions

Adjust the Idle Speed and Mixture of Your Carburetor

1. Turn off your car's engine and lift the hood.

2. Locate the air filter and remove it. Locate and remove the accompanying air cartridge.

3. Turn the "idle mixture screw" clockwise. Stop turning it once the registering needle reaches the seat.

4. Turn the same screw back counterclockwise. Complete one and a half rotations. If your vehicle has a carburetor with a main jet adjustment located at the bottom of the float bowl, you'll need to turn that screw counterclockwise until it touches the emulsion tube's seat.

5. Secure the air filter and cartridge back in their original positions.

6. Restart your engine.

7. Allow the engine to run for a few minutes. This will raise the engine's temperature. Run the engine at half throttle.

8. Locate the "idle mixture screw." Turn it clockwise. Once the engine has slowed, turn the screw back half way again.

9. Set an aluminum-cylinder engine to run at 1,750 RPM. An engine that features a cylinder sleeve made of cast-iron should be set to run at 1,200 RPM.

Adjust a Carburetor's Choke Linkage

1. Remove the air filter and cartridge from your engine.

2. Find the choke lever. It will either be found on the engine itself or within the remote speed controls.

3. Change the settings to "fast" or "high," as described on your equipment.

4. Relax the mounting brackets around the cable casings. You'll want the casings to move freely.

5. Adjust the cable casings until the engine's choke is closed.

6. Screw the cable mounting back into place.

7. Inspect the control lever's motion. Continue these adjustments until the choke linkage has been set to your liking.

Tips & Warnings

• It might be possible to clean or adjust a carburetor without removing it from the engine. There are several products specially designed to make it easy for even a automotive repair novice to care for his carburetor.

• You may want to invest in a tachometer to help get a good understanding of the speed at which your car's engine runs.

• Bad cases of carburetor contamination can cause an engine to fail completely.