Disassembly/Assembly

Carburetor - Exploded View:

UPPER BODY

1. Remove the fuel inlet fitting, fuel filter, gasket and spring (1, 2, 3, 4).
2. Remove the E-rings on the accelerator pump rod and the choke control rod and disengage the rods (5, 6, 7).
3. Remove the air cleaner stud.
4. Remove the seven screws retaining the upper body assembly. Remove the upper body.
NOTE: Position of all long screws for assembly. (Five long-silver; two short-black).
5. Remove the float hinge pin and the float assembly (10, 11).
6. Remove the float bowl gasket (12).
7. Remove the fuel inlet valve, seat and gasket (13, 14, 15).
8. Remove the accelerator pump link retaining screw (17) and nut (17A). Accelerator pump adjusting nut (20) and accelerator pump link (18). Remove the accelerator pump overtravel spring (6A), E-clip (6C), and washer (6B).
9. Remove the accelerator pump rod and the dust seal (6, 16).
10. Remove the E-ring on the choke hinge pin and slide the pin out of the casting (5, 21).
11. Remove the cold enrichment rod (CER) adjusting nut (23A) (turn counterclockwise).
NOTE: Epoxy on the nut cavity may cause breakage of the choke control rod (7). The rod has a circular undercut designed to break a 1.13 N-m (10 lb. in.) torque. If breakage occurs, a new choke control rod and a new service swivel assembly must be installed.

Cold Enrichment Rod:

12. Remove the cold enrichment rod lever, adjusting swivel, control vacuum regulator, and adjusting nut as an assembly. Disassemble as required (22, 23, 24, 25).

Venturi Valve Pivot Pin:

13. Slide the cold enrichment rod out of the upper body casting (2-6).
14. Remove the two Torx-head screws securing the venturi valve cover using venturi valve cover screw bit. Invert carburetor assembly, holding venturi valve cover in place, and remove venturi valve cover, gasket and bearings as an assembly (27, 28, 29, 30).
15. Using a pivot pin tool, press the tapered plugs out of the venturi valve pivot pins (32).

Removing Jet Plugs:

16. Push the venturi pivot pins out and slide the venturi valve to the rear until it is free of the casting (31, 32).
17. Remove the venturi valve pivot pin bushings (34).
18. Remove the metering rod pins (on the outboard sides of the venturi valve), the metering rods and the springs (35, 36, 37).
NOTE: Identify the rods, "throttle" or "choke" side, for proper assembly.
CAUTION: Always block the venturi valve wide open when working on the jets.
19. Using jet plug remover, remove the cup plugs recessed in the upper body casting (38).

Main Metering Jets:

NOTE: The main metering jet setting is an important factor in the overall carburetor calibration. For this reason the following steps must be carefully followed.

20. Using the metering jet adjusting tool, turn each main metering jet clockwise counting the number of turns, until they bottom lightly in the casting. Record the number of turns (39, 40).
21. Turn the jet assembly counterclockwise to remove. Remove 0-ring and identify the jets, "throttle" or "choke" side, for proper assembly (39, 40).
22. Remove the accelerator pump plunger, assemble and disassemble as required (41, 42, 43).
23. Remove the venturi valve limiter adjusting screw from the throttle side of the venturi valve (44).
24. Remove the 1/8-inch pipe plug in the fuel inlet boss if required for cleaning (45).

MAIN BODY

Venturi Valve - Exploded View:

1. Remove venturi valve diaphragm cover retaining screws, cover, spring guide and spring. Tap lightly to loosen cover, do not pry (1, 2, 3, 4).
2. Carefully loosen the diaphragm and slide it out of the main body (5).
3. Place the carburetor inverted on a clean surface, hold your hand in position to catch the accelerator pump check ball and weight while turning the carburetor over (9, 10).
4. Remove the five screws retaining the throttle body and remove the throttle body and gasket (11).
5. Using a 1-5/8-inch socket, remove the feedback stepper motor, gasket pintle valve and pintle spring (12, 12A, 12B, 12C).

THROTTLE BODY

Throttle Body - Exploded View:

1. Remove the throttle return control device sol-a-dash, solenoid, dashpot and bracket. Disengage the kickdown return spring (1, 2, 3, 4, 37, 38).
2. To remove the thermostatic choke cap retaining screws:
a. Center punch the choke cap retaining screw heads and using a 1/4-inch drill, drill the screw heads deep enough to remove the retainer from the choke cap.
b. Carefully remove the cap.
c. Remove the remaining portion of the choke cap screws with small locking pliers.
3. Remove the choke thermostatic lever screw and lever (10, 11).
4. Slide the choke shaft and lever assembly out of the casing and remove the fast idle cam and the E-clip. Remove the fast idle cam adjusting screw. Remove the choke diaphragm rod E-clip attaching the rod to the fast idle intermediate lever (12, 13, 13A, 36). Disengage the deloading rod, if so equipped.
5. Remove the fast idle intermediate lever (14).
6. Remove the choke control diaphragm cover screws, cover and return spring (15, 16, 17).
7. Remove the choke control diaphragm and rod. Disassemble if necessary. (18, 19).
8. The choke housing bushing is pressed into the casting and staked in place. Should replacement be required, it will have to be carefully pressed out. While pressing, the casting must be supported to prevent damage (20).
CAUTION: Before pressing, file or grind off the staked areas.
9. Remove (TSP off) idle speed adjusting screw (22).
10. Remove the throttle shaft retaining nut and spring, if so equipped, the fast idle adjusting lever, the nylon bushing (24A), the fast idle lever and the fast idle adjusting screw (23, 24, 24A, 25, 26). Remove the deloading lever, if so equipped. Remove the large E-clip (25A).
11. If it is necessary to remove the throttle plates, lightly scribe along the shaft and mark the plates T or C for throttle or choke side to ensure proper assembly.
CAUTION: The throttle plate screws are staked at assembly, the staked ends should be filed before removal. The old screws should be discarded.
Remove the throttle plate screws and the plates (27, 28).
12. In order to remove the throttle shaft assembly it is necessary to drive the limiter lever stop pin down until it is flush with the shaft (29). Remove the E-clip next to the venturi valve limiter lever (33).
13. Slide the throttle shaft assembly out of the casting and remove the transmission kickdown adjusting screw, if necessary (30, 31).
14. Remove the venturi valve limiter lever and bushing assembly (32).

INSTALLATION

CARBURETOR ASSEMBLY

THROTTLE BODY

Before installation, carefully support the throttle shaft assembly and drive the venturi valve limiter stop pin out of the shaft, if so equipped.

1. Place the venturi valve limiter assembly in the throttle body (32) and slide the throttle shaft into place (30). Install E-clip (33).
2. Place the throttle plates in the proper position. Note the scribed marks and turn the screws in until they are snug but not tight. With the throttle closed, tap the plates lightly to ensure proper centering. Tighten the screws to 1.1-1.7 N-m (10-15 lb-in). Stake the screws carefully (27, 28).
3. Drive the new venturi valve limiter stop pin into the shaft. Leave approximately 3.18mm (1/8 inch) exposed (29). Install attaching screws and E-clip (25A).
4. Install the E-clip fast idle lever, nylon bushing, fast idle adjusting lever, the throttle shaft retaining nut, and the fast idle adjusting screw (23, 24, 24A, 25, 25A, 26). Install deloading lever, if so equipped.
5. Install the (TSP off) idle speed adjusting screw (22).
6. If the choke housing bushing was removed, it must be carefully pressed into the housing and staked in place. The casting must be carefully supported while pressing and staking (20).
7. Install the fast idle intermediate lever, large E-clip, and the fast idle cam and adjusting screw (13, 13A, 14, 36). Install deloading lever, if so equipped.
8. Slide the choke control diaphragm rod into position and engage the rod and E-clip (18, 19).
9. Slide the choke shaft lever and pin assembly into the casting and install the choke thermostatic lever and screw (10, 11, 12).
10. Install the choke control diaphragm spring, cover and screws (15, 16, 17). Tighten screws to 1.5-2.1 N-m (10-15 lb-in).
11. Install the throttle return control device and bracket (1, 2, 3, 4, 5).

MAIN BODY

1. Position throttle body gasket on the main body and assemble main body to the throttle body (11).
2. Drop the accelerator pump check ball and weight into the pump discharge channel (9, 10).
3. Do not install the venturi valve limiter stop screw, torque retention spring, and plug at this time. They should be installed after complete assembly (7, 8). (Refer to the venturi valve WOT opening adjustment.)
4. Slide venturi valve diaphragm into main body (5).
5. Install the venturi valve diaphragm spring, spring guide, cover and retaining screws (1, 2, 3, 4). Tighten screws to 1.7-2.5 N-m (15-22 lb-in).
NOTE: Install screws loosely. Depress diaphragm stem with finger to prevent pinching diaphragm between cover and casting. Tighten screws diagonally. Release diaphragm stem.
6. Install the feedback motor (12), gasket (12A), pintle valve (12B) and pintle spring (12C). Tighten motor to 11-14 N-m (8-10 lb-ft).

UPPER BODY

1. Install the 1/8-inch pipe plug in fuel inlet boss (45).
2. Install the venturi valve limiter screw in the venturi valve (44).
3. Install 0-ring seals on main metering jets (40).
NOTE: 0-ring seals should be lubricated with a mild solution of soapy water before installation. Do not use silicone lubricant.
4. Using a metering jet adjusting tool, turn each main metering jet clockwise until it is seated lightly in the casting. Then turn each jet counterclockwise the number of turns recorded during disassembly (39).
5. Using the jet plug installer install the jet plugs. Tap lightly until the tool bottoms on the face of the casting.

Metering Rod Pivot Pins:

6. Install metering rods, the metering rod springs and the metering rod pivot pins on the venturi valve (35, 36, 37).
7. Install the venturi valve, carefully guide the metering rods into the main metering jets (33). Press down on the metering rods. If the springs are properly assembled they will spring back.
8. Install the venturi valve pivot pin bushings and the pivot pins (34, 35).
9. Carefully press the tapered plugs into the venturi valve pivot pins with a pivot pin tool.
10. Install the venturi valve cover plate roller bearings, a new gasket, and attaching screws (27, 28, 29, 30). Tighten screws to 2.7-4.0 N-m (24-35 lb. in.).
11. Install the accelerator pump operating rod and the dust seal (6, 16). Attach the E-clip and washer (6B, 6C). Slide the accelerator pump overtravel spring on to the rod (6A).
12. Insert the accelerator pump lever and swivel assembly into the pump link (18, 20).
Install the accelerator pump link screw and nut (17, 17A). Install the accelerator pump adjusting nut (20).
13. Install a new fuel inlet valve seat gasket, the seat and the valve (13, 14, 15).
14. Install a new float bowl gasket (12).
15. Install the float assembly and the float hinge E-pin (10, 11). Check and adjust float level to specification.
16. Assemble the accelerator pump return spring, cup and plunger. Place the pump piston assembly in position in the hole in the upper body (41, 42, 43).
17. Install a new service swivel assembly as follows: assemble lever (22) to swivel (23). Position the assembly and the CER nut (23A) 4-5 turns on choke control rod (7), seat the assembly.
18. Install the choke control rod. For final adjustment, see cold enrichment rod and control vacuum regulator adjustment (7).
NOTE: All choke settings must be adjusted after assembly.
19. Assemble upper body to the main body. Hold the pump piston assembly with finger and guide fit into the pump cavity in the main body (8, 8A). Install the choke control rod dust seal and tap gently to straighten the retainer (16). If the choke control rod broke during disassembly, prior to installing the upper body, a new rod must be positioned through the opening.
CAUTION: Ensure the venturi valve diaphragm stem engages the venturi valve.
20. Install the fuel filter spring, a new filter, a new inlet fitting gasket and the inlet fitting (1, 2, 3, 4). Tighten fitting to 10.2-14.1 N-m (90-125 lb-in).
21. After setting choke adjustment, install the air cleaner stud. Tighten stud to 8-12 N-m (6-9 lb-ft).
22. Slide cold enrichment rod into upper body (26).
23. Install the choke hinge pin and the E-ring (5, 21).
24. Engage the accelerator pump operating rod and the choke control rod and install the E-ring retainers (5, 6, 7).
25. Check and adjust fast idle cam.
26. After setting choke adjustment, position the gasket and install the choke cap, retaining shroud and new breakaway screws.
NOTE: Ensure the bimetal spring tab is engaged in the slotted choke shaft lever. Set the cap to specification, then tighten the screws until the torx-heads break off.
27. Install the venturi valve limiter stop screw and tighten retention spring. Follow the venturi valve limiter adjusting procedure. Install the plug after the adjustment is made (Main Body 10, 11).
28. Adjust the accelerator pump lash to specification on the vehicle after curb idle speed is set.