Disassembly

Fig. 2 Fabricating paper clip removal tool:

Fig. 3 Removing idle channel restrictor:

1. To prevent damaging carburetor throttle plate and to facilitate overhaul procedure, use an EGR spacer as a holding fixture.
2. Remove four throttle body to main body attaching screws, then the lower throttle position sensor mounting screw, if equipped.
3. Tap assembly gently to separate throttle body and main body.
4. Rotate throttle body and disconnect accelerator pump operating link from throttle return spring lever, noting position of link.
5. Remove throttle body from main body.
6. Remove throttle position sensor actuating pin before inverting air horn/main body assembly and retain pin.
7. Remove throttle body gasket and clean gasket mating surfaces as necessary using suitable plastic scraper. Do not use metal scraper.
8. Remove three solekicker to main body attaching screws, then the solekicker.
9. Remove choke shaft nut and lock washer and the choke pulldown lever. Hold choke plate in closed position at its upper edge while removing nut.
10. Remove choke control lever retaining screw and fast idle cam retainer.
11. Note position of fast idle cam anti- entrapment spring in relation to fast idle cam and fast idle cam link, then carefully remove fast idle cam, anti- entrapment spring and bushing, fast idle cam link and retaining bushing and choke control lever as an assembly.
12. Remove eight air horn to main body attaching screws, noting location of choke wire clip and part number tag for proper assembly. Do not pry air horn from main body. Tap air horn gently upward, not from side to side, with plastic hammer or screwdriver handle.
13. Remove air horn from main body by lifting straight up. Do not rotate air horn.
14. Remove air horn gasket, cleaning gasket mating surfaces with suitable plastic scraper. Do not use metal scraper.
15. Remove choke bi-metal assembly as follows:
a. Check rivets to determine if mandrel is well below rivet head. If mandrel is within rivet head thickness, drive it down or out using a 1/16 inch diameter tip punch.
b. Select a 1/8 inch diameter or No. 30 drill and drill into rivet head until head comes loose from rivet body. Excessive pressure on drill bit may cause rivet to spin in hole.
c. Drive remaining rivet out of hole using 1/8 inch diameter punch.
d. Repeat steps 15a through 15c on other rivet.
e. Remove standard screws, then the choke cap. Do not immerse electric choke in cleaner. Clean by wiping dirt from choke cap and gently blowing out the inside with compressed air. Replace corroded or damaged assemblies.
16. Remove accelerator pump piston bracket retaining screw and the pump/piston bracket assembly. Do not immerse pump plunger and cup assembly in cleaner.
17. Remove auxiliary main jet/pullover valve operating rod and spring from air horn. Do not immerse auxiliary main jet seal puck in cleaner.
18. Remove accelerator pump operating rod attaching screw and retainer clamp.
19. Rotate accelerator pump operating rod and remove rod and grommet from air horn. Do not immerse operating rod grommet in cleaner.
20. Remove main system feedback diaphragm and actuator assembly retaining screws.
21. Remove main system feedback diaphragm and actuator assembly, diaphragm seat, O-ring and spring from air horn.
22. Remove main system feedback diaphragm adjustment lead sealing disc from air horn screw boss by drilling a 3/32 inch diameter hole through disc and inserting a small punch to pry disc out. Do not immerse main system feedback diaphragm and actuator assembly, diaphragm seat and O-ring in cleaner.
23. Remove mechanical fuel bowl vent paddle by tightly gripping bowl vent arm and pulling firmly outboard from air horn casting, noting position of bowl vent arm spring for proper assembly. Use caution when handling components so that they will not be damaged. Always rest air horn upside down so that gasket surface, pump assembly, auxiliary main jet/pullover jet operating rod and main system feedback actuator will not be damaged.
24. Remove bowl vent arm grommet. Do not immerse bowl vent seal puck and grommet in cleaner.
25. Inspect choke plate for nicks, burrs or wear and replace as necessary.
26. Invert carburetor main body and catch accelerator pump discharge weight and ball.
27. Remove fuel inlet valve and fitting assembly and the gasket.
28. Remove float shaft retainer, float shaft and float and bushing assembly.
29. Using suitable tool, remove main metering jet, being careful not to damage jet. The auxiliary main metering jet is pressed into main body and must not be removed.
30. Using suitable tool, remove main system feedback valve assembly.
31. Remove WOT pullover enrichment valve assembly.
32. Remove main nozzle from main body by lightly tapping it upward from bottom of main body. O-ring at main well end of nozzle will tear. Be sure to remove any O-ring fragments from nozzle and/or main well.
33. Remove two pulldown diaphragm and linkage attaching screws, disconnect vacuum hose from main body and remove pulldown diaphragm and linkage assembly, noting location of exhaust gas oxygen sensor wire clip for proper assembly. Do not immerse pulldown diaphragm and linkage assembly or vacuum hose in cleaner.
34. Remove two throttle position sensor to main body attaching screws and the throttle position sensor from main body.
35. Remove WOT A/C cut-off switch to main body attaching screws and the WOT A/C cut-off switch from main body.
36. Remove two retaining screws securing hot idle compensator cover, then the cover and gasket. The hot idle compensator valve is pressed into main body and must not be removed.
37. Remove idle mixture concealment plug as described under ``Concealment Plug Removal.''
38. Turn mixture screw clockwise until it seats lightly, recording number of turns required. Do not tighten needle against its seat. If screw is bent or grooved where it seats, replace screw.
39. Inspect throttle plate and shaft for nicks, burrs or wear. Do not remove throttle place or shaft from throttle body. If wear or damage is evident, replace complete throttle body assembly.
40. Remove idle channel restrictor and O-ring assembly from throttle body using paper clip bent to specifications, Fig. 2. Insert paper clip carefully through restrictor and hook it under bottom edge, then gently pull restrictor and O-ring from throttle body, Fig. 3. Do not immerse idle mixture screw O-ring or idle channel restrictor O-ring in cleaner.