Fix It

Put the motorcycle in neutral and ensure the petcock is closed. Start and run the motorcycle until it coughs to a stop. Attempt to restart the motorcycle to ensure that the carburetor is completely out of gasoline.

Reach under the fuel tank, just in front of your left knee, and unclip the enrichener knob. Let the knob and cable hang free.

Loosen the air cleaner cover bolts. The air cleaner is between the cylinders and the original cleaner is either round or elliptical depending on the year of your FXST. Remove the bolts using either a Torx or Allen socket, depending on the year of your bike and whether you have already replaced this cover, and a socket wrench.

Pull out the two breather tubes that plug into the body of your air cleaner and let them hang free.

Unbolt and remove the air cleaner, which contains a metal or paper filter, using either a Torx or an Allen socket and a socket wrench.

Loosen the fuel line hose clamp with a flat-head screwdriver and pull this tube from the body of the carburetor.

Follow both throttle cables from the throttle to the carburetor throttle cam. Mark the front and back cables with masking tape and a pen, then unscrew and disconnect both cables. Let those cables hang free.

Unbolt and remove the air cleaner backing plate with an Allen socket and a socket wrench.

Rock the carburetor from side to side and pull it out of the black, rubber boot that connects the carburetor to the intake manifold. Gently pull the enrichener assembly through the engine and remove the carburetor and enrichener assembly as a unit.

Unscrew and remove the enrichener cable from the back of the old carburetor. Screw the enrichener cable assembly into the same location on the back of the replacement carburetor. Hand-tighten the plastic cable sealing cap.

Snake the enrichener knob and cable through the engine under the fuel tank. Seat the new carburetor in the intake manifold boot.

Replace the air cleaner backing plate with an Allen socket and socket wrench. This is the plate that actually holds the carb to the engine.

Replace both throttle cables on the throttle cam exactly as they were when you started. Remove the masking tape.

Replace the air cleaner and the air cleaner cover using either a Torx or an Allen socket and a socket wrench. Re-secure the enrichener knob into the clip on the left side of the motorcycle.

Replace the breather tubes. Start the bike to ensure it runs before replacing the air cleaner cover.

Replace the air cleaner cover using a Torx or Allen socket and socket wrench.

Set the carburetor, top-side up, on a bed of rags on a stable surface. Remove the four screws that hold the top on the carburetor with a flat-head screwdriver.

Remove the top, the small collar and the long spring. Lift out the vacuum piston from the middle of the carburetor along with the small parts inside.

Remove the needle and the spring seat from the vacuum piston.

Reassemble by placing the needle through the center hole in the vacuum piston. Place the spring seat over the top of the needle.

Reinsert the vacuum piston into the carburetor body so the vacuum piston fits in the slide track grooves. If the piston does not fit, turn it 180 degrees. Ensure the diaphragm seats evenly in the groove on top of the carburetor body.

Place the spring over the spring seat, and carefully lower the top. Hold the top down with one hand.

Insert one finger from your other hand into the venturi, and raise and lower the vacuum piston to ensure the spring is not binding.

Screw the top back on the carburetor with a flat-head screwdriver.

Locate the two idle mixture screws (one on each side) of the Holley carburetor and turn both screws carefully counterclockwise with a screwdriver until they bottom out and you feel resistance. Do not over-tighten the idle screws.

Turn both screws one-and-a-quarter turns clockwise with a screwdriver to find the idle adjustment starting point. Start the motor and allow it to warm up for about five minutes.

Remove the rubber vacuum hose from the metal vacuum port on the side of the carburetor and attach the vacuum gauge hose to the end of the port. Have someone place the car in gear and hold it still while you are adjusting the idle mixture screws.

Turn the idle screws one quarter-turn clockwise at a time in sequence with a screwdriver until you have the highest vacuum readings for both idle mixture screws. Put the car into park and leave it idling.

Repeat the procedure in Step 4, adjusting the idle mixture screws with a screwdriver while the vehicle is in park, until you get the highest vacuum readings. Remove the vacuum gauge from the carburetor vacuum port and reattach the vacuum hose to the port.