Assembly

1. Before assembling carburetor, parts should be soaked in suitable carburetor cleaning solvent, except for choke diaphragm, choke heater and some plastic parts. Do not place these parts in any liquid. Clean external surfaces of these parts with clean cloth or soft brush. Shake dirt or other foreign matter from plunger side of diaphragm. If water is used as a rinse, all traces of water must be blown from passages with compressed air.
2. Check throttle shaft for excessive wear in throttle body. If wear is extreme, replace throttle body assembly.
3. Install idle mixture screws in body, ensuring that tapered portion is straight and smooth. If tapered portion is grooved or ridged, use new screws.
4. Install plastic caps or new concealment plugs.
5. Invert main body, place insulator in position, place throttle body on main body, align parts, install attaching screws and tighten securely.
6. Install 5/32 inch diameter accelerator pump discharge check ball in discharge passage.
7. Drop 3/16 inch diameter accelerator pump intake check ball into bottom of pump cylinder.
8. Check operation of accelerator pump system as follows:
a. Pour clean gasoline into carburetor bowl, approximately 1/2 inch deep.
b. Remove pump plunger from container of mineral spirits and slide down into pump cylinder.
c. Raise plunger and press lightly on plunger shaft to expel air from pump passage.
d. Using a small clean brass rod, hold discharge check ball down firmly on its seat and again raise plunger and press downward.
e. If fuel is emitted from intake or discharge passage, clean passage again and repeat test.
f. If leakage is still apparent, stake check ball seats, remove and discard old check balls and install new check balls.
9. Install new gaskets on venturi cluster, install cluster in position in main body, install attaching screws and tighten securely.
10. Install main metering jets.
11. Install floats and fulcrum pin.
12. Install fulcrum pin retainer and baffle.
13. Install fulcrum inlet needle valve, seat and gasket in main body, then adjust float as described under ``Adjustments''.
14. Place accelerator pump drive spring on pump plunger shaft and insert shaft into air horn, then compress spring far enough to insert ``S'' link.
15. Install pump lever, vacuum piston rod lifter and accelerator pump arm in air horn.
16. Drop intake check ball into pump bore and install baffle into main body.
17. Place step-up piston spring in piston vacuum bore, position new gasket on main body and install air horn.
18. Install air horn retaining screws and tighten alternately, a little at a time, to compress gasket securely.
19. Qualify step-up piston by adjusting gap by turning Allen head adjustment screw on top of piston until gap is .035 inch. Record number of turns and direction required to obtain this dimension as it must be set to its original position after adjusting vacuum step-up piston.
20. Carefully position vacuum piston metering rod assembly into bore in air horn, ensuring that metering rods are in main metering jets.
21. Place two lifting tangs of plastic rod lifter under piston yoke.
22. Slide shaft of accelerator pump lever through rod lifter and pump arm.
23. Install two locks and adjusting screws, but do not tighten until after adjustment is made.
24. Install fast idle cam and linkage, tightening retaining screws securely.
25. Connect accelerator pump linkage to pump lever and throttle lever, then install retaining clip.
26. Inspect diaphragm vacuum fitting to ensure that passage is not plugged, then leak check diaphragm to determine if it has internal leaks.
27. To leak check diaphragm, proceed as follows:
a. Depress diaphragm stem.
b. Place finger over vacuum fitting to seal opening.
c. Release diaphragm stem.
d. If stem moves more than 1/16 inch in ten seconds, replace assembly.
28. Install diaphragm assembly on air horn as follows:
a. Engage choke link in slot in choke lever.
b. Install diaphragm assembly and secure with attaching bolts.
c. Inspect rubber hose for cracks before placing it on correct carburetor fitting. Do not connect vacuum hose to diaphragm fitting until after vacuum kick adjustment has been made.
d. Loosen choke valve attaching screws slightly.
e. Hold valve closed with fingers pressing on high side of valve, then tap valve lightly with screwdriver to seat it in air horn.
f. Tighten attaching screws securely, then stake them by squeezing with pliers.