Jeeps equipped with the original 2.5-liter four-cylinder or 4.2-liter six-cylinder engines came from the factory with a Carter carburetor. There are several variations of the Carter carburetor that have either a single- or two-barrel body and electronic emission controls. Some owners may feel the carburetor does not deliver sufficient fuel and air to meet their off-road needs. If you want to change yours, Weber makes several replacement carburetors for Jeep CJ and Wrangler YJ models.
Disconnect the cable from the negative terminal on the battery. Remove the air cleaner assembly and fuel supply hose. Label the hose and plug it to prevent fuel from leaking. Remove and plug any vacuum hoses. Separate the vacuum advance hose and set it aside. Disconnect any electrical connectors.
Disconnect the throttle linkage and remove the carburetor and any spacers from the intake manifold using a wrench. Double-nut the manifold studs and use a wrench to remove them.
Clean the manifold. Use the gasket scraper to remove the gasket and all leftover gasket material. Use carburetor cleaner to remove residue. Take care not to get any material in the intake manifold.
Mount the gasket using sealant adhesive. Use the hex wrenches to mount the plate to the manifold. Ensure that the hex bolts are flush. Mount the second adapter plate to the first and install the PCV fitting. Connect the provided 3/8-inch hose to the PCV source using the provided hose clamps and a screwdriver.
Install the Weber Carburetor. The second adapter plate has four mounting studs that match the carburetor. Set the carburetor on the studs, ensuring the fuel inlet faces toward the front of the Jeep. Install the linkage bracket on the left side and bolt the assembly in place using a wrench.
Reinstall the throttle linkage. Attach the long rod to the bell crank linkage. Connect the throttle return spring to the lower lever on the carburetor. Make sure the choke plates and throttle open and close completely.
Locate the fuel supply hose and connect it to the fuel inlet using a screwdriver and the provided hose clamp. Connect the vacuum advance hose to the vacuum advance hose port on the carburetor. Leave all other vacuum hoses plugged. Connect the electric choke wire to the electric choke on the carburetor.
Re-connect the cable to the negative terminal of the battery and start the Jeep to test. Warm the engine to operating speed before adjusting the idle speed. Use a screwdriver to adjust the idle mixture by turning the mixture screw clockwise until the idle drops off. Turn the screw counterclockwise until the idle drops again. Rotate the screw until it is halfway between the two idle drop points. Set the fast idle when the engine is cold. With the engine off, press the gas pedal to the floor, then release. Start the engine without touching the gas pedal and adjust the fast idle screw until the engine rpm is between 2000 and 2500.
