Fix It

Remove the fuel line from the carburetors fuel bowl. Fuel line attachments vary. The most typical style is a slip-on fitting with a hose clamp. Use a screwdriver to loosen the hose clamp, and pull the hose from the carburetor. Use a rag to soak up any spilled fuel.

Remove the fuel bowl from the carburetor. Remove the four hex head bolts that retain the fuel bowl and metering block using the 5/16-inch nut driver. Using the handle of the screwdriver, tap lightly on the fuel bowl to loosen it, and set the fuel bowl aside.

Remove the metering block to expose the power valve. Again, tap gently on the metering block to free it from the carburetor main body.

Unscrew the power valve from the metering block using a 1-inch wrench.

Install a gasket on the new power valve, and thread the valve into the metering block. Tighten hand-tight plus 1/8 turn.

Using new gaskets, reassemble the carburetor. Attach the power valve side of the metering block to the main body, followed by the fuel bowl. Insert the fuel bowl bolts into the fuel bowl, and tighten the bolts finger tight plus 1/4 turn.

Reattach the fuel line to the inlet on the fuel bowl, and tighten the hose clamp.

Remove air cleaner assembly from engine. Remove air box and tuning, then remove hoses and tubing leading to carburetor. Wrap tape around hoses and tubes to mark proper location for return.

Remove nuts and bolts of carburetor with wrenches from the intake manifold.

Remove old carburetor gasket from intake manifold.

Clean gasket area. Use degreaser and rag to clean gasket area. Spray degreaser directly to surface and allow degreaser to work. Prep area for new gasket to secure a proper fit.

Apply gasket sealer to both sides of the new gasket and place new gasket in proper position.

Attach new carburetor and use screwdriver and wrench to secure it to the intake manifold.

Notice the locations marked on the masking tape wrapping the hoses and tubing of the carburetor. Reconnect hoses and tubing to proper positions according to the locations marked on the tape.

Pour a small amount of gasoline into carburetor and start the engine. Pump the gas pedal a few times to get gas flowing to the carburetor.

Replace air cleaner assembly and take a short test drive on the highway to make sure carburetor is operating. After returning from the highway, let car idle for a few minutes to check for leaks.

Disassemble the carburetor completely. Remove the top air horn from the float bowl. Remove the float, accelerator pump, metering rods and jets. Remove the body flange assembly from the float bowl assembly. Do not remove the throttle valve or choke valve from the shafts. Keep small parts in a container such as an old coffee can to prevent them from becoming lost or damaged.

Soak all metal carburetor parts in carburetor cleaning dip. Do not soak any rubber or leather parts such as the accelerator pump or choke housing. Allow the parts to soak until all grease and dirt has been removed. In warmer weather soaking the parts for as little as 20 minutes is usually sufficient. In colder weather, cleaning may take several hours. Remove the parts from the carburetor dip and rinse off with clean water. Blow dry the parts using compressed air making sure that all passages in the carburetor body are clear. It may be necessary on a very dirty carburetor to use a wire brush and pipe cleaners to properly clean everything.

Install the float bowl onto the body flange using a new gasket. Install the jets into the float bowl. Install the needle valve and float. Adjust the float by turning the carburetor upside down and allow the float to hang freely. Measure the distance from the soldered seam on the float to the machined surface of the float bowl. Bend the tab on the float with a slotted screwdriver to adjust the float to the proper specifications for the model carburetor you are working on.

Install and adjust the metering rods on W1 and WGD models. Record the metering rod numbers stamped on the rods and select the proper rod gauge from the carburetor gauge kit. Adjust the metering rods by backing off on the throttle adjusting screw until the throttle valve is fully closed. Insert the metering rod gauge in place of one of the metering rods making sure the tapered end is inserted into the jet. Push down on the vacuum piston link until the finger of the piston link touches the lip of the metering arm. Clearance should be .005 inch between the bearing on the metering arm and the lower notch on the gauge. Bend the lip on the metering arm with a pair of needle nose pliers to make the adjustment.

Install and adjust the metering rods on WE models. Hold the throttle lever set screw and back out the throttle valve seated in the bore. Press down on the vacuum meter link until the rods bottom out. Hold the rods in this position and revolve the metering rod arm until the lip on the arm contacts the vacuum meter link. Hold the the metering rod in this position and tighten the metering arm set screw.

Adjust the accelerator pump for seasonal variations. The accelerator pump is adjustable by means of three holes in the pump arm. Set the pump link in the lower hole for summer, the middle hole for intermediate climate, and the upper hole for winter.

Adjust the unloader cam and boss. Close the choke manually and insert a .010 feeler gauge between the cam and boss. Loosen the choke arm and move the boss to set to specification. Adjust the lip on the throttle arm with a pair of needle-nose pliers so the choke valve will open 3/16 inch at wide open throttle.

Adjust the pump jets for proper aim. On most models there is a target mark in the venture on the opposite wall form the jets. Gasoline should squirt directly on the target when the throttle is opened. Bend the jets gently with a pair of needle nose pliers until the stream of gasoline hits the target. On carburetors without a target mark aim the gas stream to hit in a 3/16 inch diameter circle located 11/64 inch form the opposite side of the bore.

Adjust the fast idle. Close the choke valve by hand. Turn the fast idle screw until a .0012 inch wire gauge just fits between the throttle valve and and carburetor casting.

Multiply the engine displacement, in cubic inches, by the engines maximum speed, in revolutions per minute (RPM). If your engine displaces 300 cubic inches with each stroke and works at up to 3,200 RPM: 300 x 3,200 = 960,000.

Divide your answer by 3,456. 960,000 / 3,456 = 277.78.

Divide your answer by the engines efficiency, which is typically close to 85 percent. 277.78 / 0.85 = 326.8. This is your required carburetor size in cubic feet per minute.