Carter WCFB 4 - Pontiac Custom Safari 55 56 & 57

ENGINE FUEL-CARTER FOUR BARREL 6B-21 

INLET 

Fig. 68-40 

Float Circuit 

Fig. 68-39 

Carter WCF8 Four-Barrel Climatic (R) 

Control Carburetor 

DESCRIPTION 

CARTER WCFB FOUR-BARREL 

CLIMATIC (R) CONTROL 

CARBURETOR 

NOTE: The following illustrations are used by 

permission of the copyright owner, Carter Carburetor 

Corporation, St. Louis, Missouri: Figs. 6B- 

39 through 6B-47 and Figs. 6B-64 through 6B-70. 

The Carter Model WCFB carburetor (Fig. 6B-39) 

is basically two dual carburetors contained in one 

assembly. The section containing the metering rods, 

accelerating pump and choke is termed the primary 

side of the carburetor; the other section, the secondary 

side. It has five (5) conventional circuits, as have 

been used in previous carburetors. They are: 

2-Float Circuits 

I-Low Speed Circuit 

2-High Speed Circuits 

I-Pump Circuit 

I-Climatic (R) Control (choke) Circuit 

flOAT CIRCUITS (FIG. 68-40J 

The purpose of the float circuits is to maintain an 

adequate supply of fuel at the proper level in the 

bowls for use by the low speed, high speed, pump and 

choke circuits. Primary and secondary bowls are 

separated by a partition. A connecting passage along 

the outside of the body effects a balance of the fuel 

levels and pressures between the two bowls. The fuel 

line connection is on the primary side. Fuel is supplied 

to the primary and secondary intake needles 

and seats through a passage in the bowl cover. There 

are three strainer screens in the bowl cover. They are 

located at the fuel inlet and at both primary and secondary 

needle seats. 

Setting the floats to specifications assures an adequate 

supply of fuel in the bowls for all operating conditions. 

Float adjustments must be made with the 

bowl cover gasket removed and should be checked 

vertically (specified distance between bowl cover and 

bottom of floats) and laterally (sides of floats should 

just clear the arms of gauge) (see adjustment-page 

6B-33). Correct lateral adjustment is important. If the 

floats are misaligned, they may bind or drag against 

the walls of the bowl. 

Intake needles and seats are carefully matched 

during manufacture. Do not use the primary needle 

in the secondary seat or vice versa. To avoid unnecessary 

bending, floats should be reinstalled in their 

original positions and then adjusted. 

The bowls are vented to the inside of the air 

cleaner and also to atmosphere. The bowl vents are 

calibrated to provide proper pressure above the fuel 

at all times. The bowl cover gasket seals the fuel 

bowl, idle and vacuum passages. To assure a positive 

seal, always use a new bOWl cover gasket when reassembling. 

An air leak at this point can result in a 

performance or economy complaint. 

www.PontiacSafari.com

6B-22 1955 PONTIAC SHOP MANUAL 

SECONDARY SIDE PRIMARY SIDE JET 

Fig. 68-41 

Low Speed Circuit 

Fig. 68-42 

High Speed Circuits 

LOW SPEED CIRCUIT (fIG. 6B-4JJ 

Fuel for idle and early part throttle operation is 

metered through the low speed circuit. 

Fuel enters the idle wells through the metering rod 

jets on the primary side of the carburetor. No idle 

system is used in the secondary side of the carburetor. 

The low speed jets measure the amount of fuel for 

idle and early part throttle operation. The air by-pass, 

economizer, and idle air bleed are carefully calibrated 

and serve to break up the liquid fuel and mix it with 

air as it moves thrpugh the passages to the idle ports 

and idle adjustment screw ports. Turning the idle 

adjustment screws toward their seats reduces the 

quantity of fuel mixture supplied by the idle circuit. 

The idle ports are slot shaped. As the throttle 

valves are opened, more of the idle ports are uncovered 

allowing a greater quantity of fuel and air 

mixture to enter the carburetor bores. The secondary 

throttle valves remain seated at idle. 

Air leakage at the gasketed surface surrounding 

the low speed mixture passages or between the flange 

and manifold may cause poor idle and low speed 

operation. Always use new gaskets. 

All by-passes, bleeds, economizers, idle ports, idle 

mixture adjustment screw ports, as well as the bores 

of the flange must be clean and free of carbon. Obstructions 

will cause poor low speed engine operation. 

Worn or damaged idle adjustment screws or low 

speed jets should be replaced. 

To combat engine stalling during warm-up on cool, 

humid days, caused by "carburetor icing", exhaust 

gas is circulated through a passage in the base of the 

carburetor flange. The heat transferred is sufficient 

to eliminate ice formation at the throttle valve edges 

and idle ports. 

HIGH SPEED CIRCUITS (fIG. 6B-421 

Fuel for part throttle and full throttle operation 

is supplied through the high speed circuits. Main discharge 

nozzles are permanently installed and must 

not be removed in service. 

PRIMARY SIDE 

The position of the metering rods in the metering 

rod jets controls the amount of fuel flowing in the 

high speed circuit of the primary side of the carburetor. 

The position of the metering rods is dual controlled; 

mechanically by movement of the throttle, 

and by manifold vacuum applied to the vacuum 

piston on the vacumeter link. 

MECHANICAL METERING ROD ACTION 

During part throttle operation, manifold vacuum 

pulls the vacumeter piston, link and metering rod assembly 

down holding the vacumeter link against the 

metering rod countershaft arm (Fig. 6B-43). Movement 

of the metering rods will then be controlled by 

the metering rod countershaft arm which is connected 

to the throttle shaft. This is true at all times that the 

vacuum under the piston is strong enough to overcome 

the tension of the vacumeter spring. 

VACUUM METERING ROD ACTION 

Under any operating condition (acceleration, hill 

climbing, etc.) when the tension of the vacumeter 



METERING ROD 

COUNTERSHAFT AR~'\7";'m~;::::,".w 

METERING 

PUMP 

JET 

NOZZLE 

-====~ DISCHARGE 

..::::=~I-t-- CHECK 

NEEDLE 

Fig. 68-43 

Metering Rods and Vacumeter Piston 

spring overcomes the pull of vacuum under the 

piston, the metering rods will move toward their wide 

open throttle or power position. 

Fig. 68-44 

Pump Circuit 

SECONDARY SIDE 

Fuel for the high speed circuit of the secondary 

side is metered at the secondary main metering jets 

(no metering rods used). 

Throttle valves in the secondary side remain closed 

until the primary throttle valves have been opened 

a predetermined amount. They arrive at wide open 

throttle position at the same time as the primary 

valves. This is accomplished by linkage between the 

throttle levers. 

Secondary throttle valves are locked closed during 

choke operation to assure proper cold engine starting 

and warm-up. 

ANTI-PERCOLATOR 

To prevent vapor bubbles in the nozzle passages 

and low speed wells from forcing fuel out of the 

nozzles, anti-percolator passages with calibrated vents 

are used. Their purpose is to vent the vapors and relieve 

the pressure before it is sufficient to push the 

fuel out of the nozzles and into the intake manifold. 

Anti-percolator vent plugs and bushings are permanently 

installed and must not be removed in service. 

PUMP CIRCUIT (FIG. 68-44J 

The pump circuit is located only in the primary 

side of the carburetor. 

The accelerating pump circuit provides the measured 

amount of fuel necessary to ensure smooth engine 

operation during acceleration at speeds below 

approximately 30 MPH. 

When the throttle is closed the pump plunger 

moves upward in its cylinder and fuel is drawn into 

the pump cylinder through the inlet passage. The 

discharge needle is seated at this time to prevent air 

being drawn into the cylinder. When the throttle is 

opened the pump plunger moves downward forcing 

fuel out through the discharge passage, past the discharge 

needle, and out of the pump jets. When the 

plunger moves downward the inlet valve is closed preventing 

fuel from being forced back into the bowl. 

If the throttle is opened suddenly, the plunger 

shaft will telescope compressing the pump spring. 

The spring will then push the plunger down resulting 

in a smoother pump discharge of longer duration. 

At speeds above approximately 30 MPH pump discharge 

is no longer necessary to ensure smooth acceleration. 

When the throttle valves are opened a predetermined 

amount, the pump plunger bottoms in the 

pump cylinder eliminating pump discharge. 



REVOLVING TYPE 

BAFFLE 

CHOKE OPERATING 

TH 

SLOTS IN CHOKE 

PISTON CYLINDER 

Fig. 68-46 

Choke Housing Detail 

Fig. 68-45 

CHOKE CIRCUIT (FIG. 68-45) 

Choke Circuit 

The Climatic (R) control circuit provides a correct 

mixture necessary for quick cold engine starting 

and warm-up. 

When the engine is cold, tension of the thermostatic 

coil holds the choke valve closed. When the engine 

is started, air velocity against the offset choke 

valve causes the valve to open slightly against the 

thermostatic coil tension. Intake manifold vacuum 

applied to the choke piston also tends to pull the 

choke valve open. The choke valve assumes a position 

where tension of the thermostatic coil is balanced 

by the pull of vacuum on the piston and air velocity 

on the offset choke valve. 

entering the housing from striking the thermostatic 

coil until the choke valve opens a predetermined 

amount. This serves to delay the opening of the choke. 

When the engine is accelerated dUring the warmup 

period, the corresponding drop in manifold vacuum 

applied to the choke piston allows the thermostatic 

coil to momentarily close the choke, providing 

a richer mixture. 

'I.",'I: ...... ~ ,-;,;;J/j/'--CHOKE LEVER 

When the engine starts, slots located in the sides 

of the choke piston cylinder (Fig. 6B-46) are uncovered 

allowing intake manifold vacuum to draw 

warm air from the hot air tube, located in the exhaust 

crossover passage of the intake manifold, through 

the Climatic (R) control housing. The flow of warm 

air in turn heats the thermostatic coil and causes it 

to lose some of its tension. The thermostatic coil loses 

its tension gradually until the choke valve reaches 

wide open position. 

A secondary baffle plate revolves with the choke 

valve. The revolving baffle prevents the warm air 

Fig. 68-47 

Choke Linkage 



During the warm-up period it is necessary to provide 

a fast idle speed to prevent engine stalling. This 

is accomplished by a fast idle cam which is rotated 

by a connector rod attached to the choke shaft (Fig. 

6B-47). The fast idle cam prevents the primary throttle 

valves from returning to a normal warm engine 

idle position while the Climatic (R) control is in operation. 

During the starting period if the engine becomes 

flooded the choke valve can be partially opened manually. 

This can be accomplished by depressing the 

accelerator pedal to the floor. The unloader projection 

on the throttle lever will rotate the fast idle cam 

and in turn partially open the choke valve. 

ADJUSTMENTS ON CAR 

All adjustments with the exception of Fast Idle 

Adjustment, are included in the "OVERHAUL AND 

ADJUSTMENTS" procedure and can be done with 

the carburetor on the car. The fast idle can be adjusted 

on the car as follows: 

1. Start engine and run until engine reaches normal 

temperature. 

2. Move fast idle cam so that highest step is under 

end of fast idle screw. 

3. Observing tachometer, adjust fast idle screw to 

give an engine speed of 1900 RPM. 

OVERHAUL AND ADJUSTMENTS 

Flooding, stumble on acceleration and other performance 

complaints are, in many instances, caused 

by the presence of dirt, water or other foreign matter 

in the carburetor. To aid in diagnosing the cause of 

the complaint, the carburetor should be carefully removed 

from the engine without draining the fuel from 

the bowl. The contents of the fuel bowl may then be 

examined for contamination as the carburetor is disassembled. 

CAUTION: Whenever the carburetor is 

removed from the engine, care must be exercised to 

avoid damaging the throttle valves, as the lower edge 

of the valves project below the throttle flange when 

the valves are in the open position. 

The following is a step-by-step sequence by which 

the Carter model WCFB Carburetor may be completely 

disassembled and reassembled. Adjustments 

may be made and the various parts of the carburetor 

may be serviced without completely disassembling 

the entire unit. 

Fig. 68-48 

DISASSEMBL Y OF AIR HORN 

Metering Rod and Pump Linkage 

1. Remove gasoline strainer nut and gasket assemblies 

from primary and secondary sides and screen 

from primary side. 

2. Remove throttle connector rod. 

3. Remove choke connector rod. 

4. Remove 2 metering rod housing dust cover attaching 

screws, dust cover and gasket. 

S. Unhook countershaft return spring (Fig. 6B-48). 

6. Loosen. but do not remove screw holding the 

pump operating lever to pump countershaft. 

7. Loosen. but do not remove metering rod arm 

screw. 

8. Slide pump countershaft and lever assembly from 

air horn assembly. 

9. Remove pump arm and link assembly. spacer 

bushing and metering rod arm from metering rod 

housing. 

10. Remove both metering rods. 

11. Remove choke lever from choke shaft. 

12. Remove 3 choke coil housing screws and retainers. 



L -LONG M. -MEDIUM 5 -SHORT 

Fig. 68-49 

Location of Air Horn Attaching Screws 

Fig. 68-50 

Removing Air Horn Assembly 

13. Remove choke coil housing, gasket and then 

baffle plate. 

NOTE: Under normal service the carburetor air 

horn may be cleaned without further disassembly. 

If complete disassembly is necessary, perform operations 

a, b, and c. 

a. File off staked end of choke valve screws. Remove 

screws and valve. 

18. Remove primary needle seat with strainer 

screen and gasket. 

19. Remove secondary needle seat, strainer screen, 

and gasket. 

20. Remove vacumeter piston and vacumeter piston 

link. 

21. Remove gasket from air horn. 

b. Rotate choke shaft counter-clockwise, and remove 

shaft and piston assembly. 

c. Remove 3 self-tapping screws, choke piston 

housing and gasket. 

14. Remove 16 air horn attaching screws (Fig. 

6B-49). 

15. Carefully remove air horn assembly with gasket 

and attached parts by lifting straight up from 

carburetor body assembly (Fig. 6B-sO). 

NOTE: To avoid bending floats, be sure bowl cover 

gasket is not sticking to body casting. 

16. Remove primary float hinge pin, float assembly, 

and intake needle. IMPORTANT: Mark and group 

float assemblies with needle and needle seat together 

as units. Extreme care should be used to avoid mixing 

needles and seats. 

17. Remove secondary float hinge pin, float assembly 

and intake needle in the same manner. 

Fig. 68-51 

Carburetor 8ody-Top View 



DISASSEMBLY Of CARBURETOR BODY 

1. Remove pump plunger assembly and lower pump 

spring. 

2. Remove vacumeter spring (Fig. 6B-Sl). 

3. Check the fuel in the bowl for contamination by 

dirt, water, gum or other foreign matter, then drain 

fuel from bowl. 

NOTE: Magnet swept around bottom of bowl 

while fuel is still present will pick up iron oxide dust 

which may have contributed to float needle leaks. 

4. Remove pump jet cluster attaching screw, then 

remove cluster and gasket. 

S. Invert carburetor and remove small brass pump 

discharge needle. 

6. Remove pump inlet ball retainer and check ball 

from bottom of pump cylinder. 

NOTE: Use o/!r," six point socket to pry sideways 

on dome of retainer to loosen it. 

Fig. 68-52 

Location of Throttle Flange Attaching Screws 

7. Remove pump passage screw plug and gasket. 

8. Remove 2 primary metering rod jets (located on 

pump cylinder side of carburetor). 

9. Remove 2 secondary main jets. NOTE: Primary 

metering rod jets have larger openings than the- secondary 

main jets. Never mix these jets. 

10. Remove two low speed jets (primary side). 

NOTE: The anti-percolator vent plugs and bushings, 

and main discharge nozzles are pressed in place 

and should not be removed. 

11. Remove the 6 throttle flange to carburetor body 

attaching screws (Fig. 6B-S2). 

12. Remove throttle flange. 

13. Remove body flange gasket. 

DISASSEMBL Y OF THROTTLE FLANGE 

1. Remove idle mixture adjusting screws with 

springs. NOTE: Under normal service the carburetor 

flange may be cleaned without further disassembly. 

If complete disassembly is necessary, perform the 

remaining operations. 

2. Remove fast idle cam screw, fast idle cam assembly, 

lockout arm and lockout arm spring. 

3. Remove primary to secondary connector rod 

pin springs and washers, then remove rod. 

4. Remove primary throttle shaft screw and washer. 

S. Remove primary throttle levers and spring as an 

assembly. 

6. Remove primary throttle shaft spring thrust 

washer. 

7. Remove secondary throttle shaft screw and 

washer. 

8. Remove secondary throttle lever, and secondary 

throttle return spring. 

9. File off staked ends of throttle valve attaching 

screws and remove screws and throttle valves from 

the four bores. 

10. Remove primary and secondary throttle shafts. 

11. Remove idle speed screw and spring. 

CLEANING AND INSPECTION 

OF PARTS 

Dirt, gum, water or carbon contamination in the 

carburetor or on the exterior moving parts of a carburetor 

are often responsible for unsatisfactory performance. 

For this reason, efficient carburetion depends 

upon careful cleaning and inspection while 

servicing. 

1. Thoroughly clean carburetor castings and all 

metal parts in clean carburetor cleaning solution. 

CAUTION: Composition and plastic parts such as 

thermostatic coil housing and pump plunger should 

not be immersed in cleaner. 



VACUUM PASSAGE TO 

CHOKE VACUUM PISTON 

Fig. 6B-53 

Passage Identification-Body to Air Horn 


ENGINE FUEL-CARTER FOUR BARREL 68-29 

VACUUM PASSAGE TO 

VACUMETER PISTON 

Fig. 6B-54 

Passage Identification-Body to Throttle Flange 

2. Blowout all passages (Figs. 6B-53-6B-55) in 

casting with compressed air and blow off all parts so 

they are free of cleaner (be sure to follow instructions 

furnished with cleaning solution). CAUTION: Do 

not use drills or wire to clean out jets or ports as this 

may enlarge the opening and affect carburetor operation. 

3. Carefully inspect parts for wear and replace 

those which are worn. Check the following specific 

points: 

a. If choke housing was disassembled in ste~ 13 

a, b, and c for complete overhaul, remove Welch plug 

in the bottom of the choke piston housing. Plug can 

be removed by piercing center with a small pointed 



Fig. 68-55 

Passage at Manifold Side of Throttle Flange 

instrument and prying outward. Care should be exercised 

so that damage will not result to the casting 

when I:(moving this plug. Before installing new plug, 

carbon,,:present in piston cylinder slots should be removed- 

and the Welch plug seat should be carefully 

cleaned. 

b. Remove carbon from bores of throttle flange 

with sandpaper; never use emery cloth. 

c. Inspect needle or seat for wear; if worn, both 

must be replaced. 

d. Inspe,ct float pin for excessive wear. 

e. Inspect float for dents and excessive wear on 

lip. Check for fluid inside float by shaking. Replace 

float if any of above are present. 

f. Inspect air horn for wear in countershaft hole 

(hole worn egg shaped). 

g. In'spect .throttle shafts for excessive wear (looseness 

or rattle in body flange casting). 

h. Inspect idle mixture adjusting screws for burrs. 

Replace if burred. 

i. In~ect metering rods and jets for bent rods and 

signs of wear, and replace if bent rods or wear are 

noted. Always replace both metering rod and jet; do 

not install new rod in old jet or vice versa. 

j. Inspect pump plunger assembly. If leather is not 

in good condition, replace plunger. 

k. Inspect gasketed surfaces between body and air 

horn, and between body and flange. Small nicks or 

burrs should be smoothed down to eliminate air or 

fuel leakage. Be especially particular when inspecting 

choke vacuum passages and the top surface of the 

inner wall of the bowl. 

4. Check part numbers of jets, metering rods, etc. 

(where stamped with Carter part number), against 

Master Parts Catalog to make. sure correct parts will 

be installed. 

ASSEMBL Y OF THROTTLE FLANGE 

l. Install idle mixture adjusting $crews and springs 

finger tight, then back out 1 turn. CAUTION: Do not 

tighten idle mixture adjusting screws more than finger 

tight. 

If throttle flange was fully disassembled, reassemble 

as follows: 

2. Install primary and secondary throttle shafts. 

3. Install primary throttle valves from top or body 

side, with trade mark (C in circle) toward idle ports 

when viewing flange from manifold side. Use NEW 



Fig. 6B-58 

Outer Throttle Lever Installed 

Fig. 6B-56 

Proper Assembly of Secondary Throttle Lever 

screws. Install secondary throttle valves with trade 

mark (C in circle) away from center of carburetor 

when viewing flange from manifold side. 

4. Install secondary throttle return spring and secondary 

throttle lever (Fig. 6B-56). 

5. Install secondary throttle washer and screw 

(Fig. 6B-56). 

6. Wind spring 1 % turns with tag wire and hook 

over secondary throttle lever (Fig. 6B-56). 

7. Install primary shaft thrust washer and inner 

throttle shaft arm (Fig. 6B-57). 

8. Install outer throttle lever (Fig. 6B-58). 

9. Install throttle shaft dog, washer, and screw. 

Hook throttle flex spring on outer throttle lever and 

throttle shaft dog (Fig. 6B-59). 

10. Using a flat washer on each side of the levers, 

install connector rod (Fig. 6B-59). Retain with pin 

springs. 

11. Install fast idle cam assembly, consisting of 

secondary lockout lever spring, secondary lockout 

lever, lower choke lever, fast idle cam and spring and 

attaching screw as follows: 

a. Assemble fast idle cam and spring assembly and 

lower choke lever and place over attaching screw and 

set aside (Fig. 6B-60). 

b. Hook secondary lockout lever spring in lockout 

lever and place lever against boss with spring hooked 

on casting (Fig. 6B-61). 

c. Install fast idle cam assembly with screw (assembled 

in step a) in position on boss (Fig. 6B-62). 

Make sure cam and levers operate freely. 

12. Install idle speed screw and spring. 

Fig. 68-57 

Inner Throttle Shaft Arm Installed 

Fig. 6B-59 

Proper Assembly of Primary and Secondary 

Throttle Levers 



FAST IDLE CAM 

Fig. 68-60 

Fast Idle Cam and lower Choke lever 

Fig. 68-62 

Fast Idle Cam and Secondary 

lockout Assembly 

ASSEMBLY OF CARBURETOR BODY 

1. Place NEW body to flange gasket on carburetor 

body being sure slot in gasket is lined up with vacumeter 

passage. 

2. Install throttle flange on carburetor body with 

6 attaching screws and lock washers (Fig. 6B-52). 

3. Install primary metering rod jets. NOTE: The 

primary metering rod jets have the large holes and 

must be installed in the primary side of the carburetor. 

This is the pump cylinder side of the carburet()r 

body. 

4. Install secondary main jets. 

5. Install 2 low speed jets on primary side of body. 

NOTE: Low speed jets are mounted at a slight angle. 

6. Install steel pump inlet ball check and retainer 

(Fig. 6B-51). Press retainer into place with a %6" 

six point socket. 

7. Install pump passage screw plug and gasket. 

8. Install brass pump discharge check needle (Fig. 

6B-63). Be sure needle is installed point down. 

9. Install pump discharge cluster gasket, cluster 

assembly and attaching screw. 

10. Install vacumeter spring in vacumeter bore. 

NOTE: The vacumeter spring affects both economy 

and performance. If vacumeter piston spring appears 

to be damaged or distorted, it should be replaced. If 

any doubt exists, use a new spring for comparison. 

Fig. 68-61 

Positioning Secondary lockout lever 

Fig. 68-63 

Installing Pump Discharge Check Needle 



Fig. 68-65 

Float Drop 

5. Remove floats and install new air horn gasket. 

Fig. 68-64 

Float Gauge in Position for Checking Floats 

11. Install lower pump spring in pump cylinder. 

ASSfMBL Y OF AIR HORN 

1. Install strainer screen in primary intake needle 

seat. Then install primary needle and seat with new 

gasket. IMPORTANT: Float needles and seats are 

factory matched and must never be mixed. 

2. Install secondary intake needle and seat with 

new gasket. 

3. Temporarily install both the primary and secondary 

float assemblies. NOTE: Float adjustments 

must be measured with air horn gasket removed. 

4. Three separate float adjustments must be made 

-lateral, vertical, and float drop. 

a. Lateral Adjustment: Place float gauge ] -545B 

under center of float with notched portion of gauge 

fitted over edge of casting (Fig. 6B-64). Sides of float 

should just clear the vertical uprights of float gauge. 

Adjustment should be made by bending arms of 

float. 

b. Vertical Adjustment: With float gauge in position, 

(Fig. 6B-64) floats should just clear the horizontal 

portion of gauge. Vertical distance between top 

of float (at center) and machined surface of casting 

is ~i6" (gauge]-545B) for both primary and secondary 

floats. Adjust by bending at center portion of 

float arms. Remove gauge. 

c. Float Drop Adjustment: With bowl cover held 

in upright position and measuring from center of 

float, the distance between top of floats and bowl 

cover should be ~i6" for both primary and secondary 

floats (Fig. 6B-65). Adjust by bending stop tabs on 

float brackets. 

6. Install vacumeter link and vacumeter piston 

with lip on link toward center of air horn. 

7. Insert pump plunger shaft through air horn and 

retain in position with link and pump arm assembly. 

B. Reinstall the primary and secondary float assemblies. 

9. Carefully position the air horn assembly on the 

carburetor body being sure the vacumeter piston and 

pump plunger are aligned so they enter their respective 

bores. 

10. Install 16 air horn attaching screws. See Fig 

6B-49 for proper location of different length screws. 

11. Tighten all screws evenly and securely in alternate 

order. 

12. Install both metering rods as follows: Catch 

metering rod spring loop with lower end of rod before 

rod is inserted, then twist "eye" of rod onto 

vacumeter piston link assembly. 

13. Install countershaft return spring on countershaft. 

14. Install pump countershaft by sliding shaft 

through pump operating arm, spacer bushing and 

metering rod arm (Fig. 6B-4B). CAUTION: Be certain 

metering rod operating arm is positioned in slot 

in vacumeter piston link. 

15. Tighten pump arm screw. 

16. Using tag wire wind countershaft spring Yz 

turn and hook over pump arm. 

17. Place washer on lower end of throttle connector 

rod, install rod into throttle lever while holding 

lever in wide open position. and retain with spring 

and retainer. 

lB. Install throttle connector rod in pump countershaft 

lever and retain with pin spring. 


68-34 1955 PONTIAC SHOP MANUAL 

19. Install choke piston housing and NEW gasket 

using three self-tapping screws. 

20. Assemble choke piston on link and install choke 

shaft and piston assembly through air horn while 

guiding piston into cylinder. 

21. Place choke valve in position on choke shaft 

with the "C" (in circle) on valve visible from the top 

of carburetor. Center choke valve and install screws. 

Use new screws. IMPORTANT: Make sure that 

neither valve nor shaft binds in any position and that 

valve drops free by its own weight. 

22. Position baffle plate into choke housing with 

choke operating lever extending through slot in stationary 

baffle and small hole in rotating baffle. 

23. Install choke coil housing and new gasket on 

piston housing with index mark on plastic housing at 

the bottom. Revolve coil housing in direction opposite 

to arrow (counterclockwise) until index mark on coil 

housing is aligned with index mark on piston housing, 

and retain with 3 screws and retainers. 

24. Install choke operating lever on shaft and 

tighten screw only enough to permit lever to be 

moved. 

25. Install choke connector rod in choke operating 

lever and choke lower lever, and retain lower end of 

rod with pin spring. 

26. Install strainer plug, gasket, and strainer in 

primary side. 

27. Drop secondary strainer into place around 

stand pipe. Carefully press down into bore around 

standpipe. Install strainer plug and gasket. 

Fig. 68-66 

Accelerating Pump Arm Adjustment 

rod at lower angle (use tool J-5496) until flat on top 

of pump arm is parallel with straight edge while 

throttle valves are seated (Fig. 6B-66). 

METERING ROD ADJUSTMENT 

1. Back out idle speed screw and fast idle speed 

screw until throttle valves seat. 

2. Press down on vacumeter piston link until metering 

rods bottom in carburetor body (Fig. 6B-67). 

3. Holding rods in this downward position and with 

throttle valves seated, revolve metering rod arm until 

finger on arm contacts lip of vacumeter link. Hold 

in place and carefully tighten clamp screw (Fig. 

6B-67). 

ADJUSTMENTS 

The float adjustments have been described and 

made during assembly of the air horn. The remaining 

adjustments should be made in the following sequence: 

1. Pump Adjustment 

2. Metering Rod Adjustment 

3. Fast Idle Cam Clearance Adjustment 

4. Unloader Adjustment 

5. Secondary Throttle Lever Adjustment 

6. Secondary Throttle Lockout Adjustment 

PUMP ADJUSTMENT 

1. Back out idle speed screw and fast idle speed 

screw until throttle valves seat in bores of carburetor. 

2. Hold straight edge across top of dust cover boss 

at pump arm (Fig. 6B-66). Bend throttle connector 

Fig. 68-67 

Metering Rod Arm Adjustment 



Fig. 68-68 

Fast Idle Cam Clearance Adjustment 

Fig. 68-69 

Unloader Adjustment 

4. Lubricate countershaft by dropping engine oil 

in 2 oil holes and install dust cover. 

FAST IDLE CAM CLEARANCE ADJUSTMENT 

1. Make sure choke lever clamp screw is still loose. 

2. Hold choke valve closed. 

3. Place .020" wire gauge (J-1388) on boss, rotate 

choke lever on shaft until tang on fast idle cam contacts 

wire gauge and all slack in linkage is removed 

(Fig. 6B-68)~ While holding in this position, tighten 

choke lever clamp screw. 

UNLOADER ADJUSTMENT 

1. Hold throttle lever wide open. 

2. There should be %" (gauge J -818-5) between 

top edge of choke valve and inner wall of air horn 

(Fig. 6B-69). If necessary, adjust by bending unloader 

projection on throttle lever. 

SECONDARY THROTTLE LEVER ADJUSTMENT 

1. Open choke valve to unlock secondary throttle 

valves. 

2. Open primary throttle lever to wide open position. 

3. Secondary throttle valves should reach wide open 

position at the same time as primary valves. If necessary, 

bend throttle operating rod at upper angle 

(Fig. 6B-70) (use bending tool T-I09-2l3). 

Fig. 68-70 

Primary and Secondary Throttle Levers 

4. Check to see that there is .017" to .022" clearance 

between primary and secondary throttle positive 

closing shoes (Fig. 6B-70). 

LOCKOUT ADJUSTMENT 

1. Hold choke valve wide open. 

2. Hold throttle lever closed. 

3. Allow choke valve to close slowly. Lockout step 

on secondary lockout lever should freely engage tang 

on secondary throttle lever (Fig. 6B-71). If adjustment 

is necessary, bend tang (Fig. 6B-7l). 



TEST BEFORE INSTALLATION 

ON ENGINE 

It is good shop practice to fill the carburetor bowl 

before installing the carburetor. This reduces the 

strain on the starting motor and battery and reduces 

the possibility of backfiring while attempting to start 

the engine. A fuel pump clamped on the bench, a 

small supply of fuel and the necessary fittings enable 

the carburetor to be filled and the operation of the 

float and intake needle and seat to be checked. Operate 

the throttle several times and check the discharge 

from the pump jets. 

Before installing the carburetor, hold choke valve 

open and turn the idle speed screw until it just contacts 

the throttle lever, then % of a turn more to open 

the throttle valves enough to keep the engine running 

until the idle mixture and final RPM adjustment 

can be made. 

TROUBLE DIAGNOSIS AND TESTING 

Excessive leanness during cold engine operation 

may indicate that the secondary throttle valves are 

partially open. Check the secondary lockout and 

check for too rapid choke opening. 

Fig. 68-71 

Lockout Adjustment 

In all other respects 4 barrel trouble diagnosis is 

the same as on the 2 barrel carburetor. See page 

6B-18 for 2 barrel trouble diagnosis. 

CARTER CARBURETOR WCFB-SPECIFICATIONS 

ADJUSTMENT SPECIFICATIONS 

Float Adjustment-Vertical distance between center of float and surface of air 

horn '%6" (gauge J-5458) for both primary and secondary. 

Float Drop-Casting in operating position distance between center of floats and 

air horn is %6" (no gauge necessary; use an ordinary scale). 

Fast Idle-Cam to machined boss clearance minimum of .020" (gauge J-1388). 

Un loader-Distance between upper edges of choke valve and wall of air horn 

Ys" (gauge J-818-5). 

Clearance Between Positive Closing Shoes-is .017" to .022" with both valves 

seated (hold choke valve open to revolve fast idle cam and be sure idle speed 

screw is backed out so valves seat in bore). 

Fast Idle Speed 

Hot Idle Speed 

1900 RPM 

390-410 HM, 450-470 SM 

Choke-Carter Climatic (R) Control-Butterfly Type, Set on Index. Offset 

choke valve on primary side only. 


ENGINE FUEL-CARTER FOUR BARREL 

6B-37 

GENERAL SPECifiCATIONS 

Flange Size 

Primary Venturi (I.D.) 

Main Venturi, Primary (I.D.) 

Main Venturi, Secondary (I.D.) 

Float Level 

Vents 

Outside 

Inside 

Gasoline Intake (In Needle Seat) 

1:%" (Four Bore-4 Bolt Type) 

Iljg2" 

1%6" 

I" HM, 1%6" SM 

See Adjustments 

Five in Bowl Cover 

Two in Dust Cover 

Three on Primary Side 

Two on Secondary Side 

.......... No. 38 Drill (.1015") 

Low Speed Jet Tube (Primary Side Only) 

Jet (DO NOT REMOVE) .. No. 68 Drill (.031") HM, No. 67 Drill (.032") SM 

By-Pass (In Body) ......... . 

Economizer (In Screw Plug) 

Idle Bleed (In Body) 

Idle Port (Primary-Upper) 

(Secondary) 

No. 53 Drill (.0595") 

.0492" 

..... No. 52 Drill (.0635") 

Slot Length .195", Width .030" 

None 

Opening Above Throttle Valve When 

Valve Is Tightly Closed (Primary) .139" to .145" 

(Secondary) 

None 

Idle Port (lower for the idle screw-Primary) No. 53 Drill (.0595") 

(Secondary) . . . . . . . . . . ......... None 

Idle Adjustment Screw Setting 

Main Nozzle (DO NOT REMOVE) 

Anti-Percolating Jet (Off Nozzle Well) 

Metering Rod (Primary) 

Economy Step ......... . 

Middle Step Tapers To 

Power Step 

Metering Rod (Secondary) 

Metering Rod jet 

Primary (for metering rod) 

Secondary (no metering rod) 

Metering Rod Setting 

Accelerating Pump 

Discharge jet (Primary) 

(Secondary) 

Intake Ball Check Seat 

Discharge Needle Seat 

Pump Adjustment ... 

0/4 to 10/4 turns open 

. Permanently Installed 

.. No. 60 Drill (.040") 

.074" HM, .072" SM 

.067" HM, .069" SM 

.059" All 

.......... None 

.0935" 

.0492" HM, .0512" SM 

.... See Adjustments 

..... No. 72 Drill (.025") 

None 

.115" to .120" 

.070" 

See Adjustment 


6B-38 

1955 PONTIAC SHOP MANUAL 

Choke Heat Suction Hole Restriction 

In Piston Housing 

Vacuum Spark Port 

Diameter ......... . 

Distance from throttle valve with valve tightly closed 

No. 45 Drill (.082") 

.062" to .064" 

.029" to .039" 

(To Top of Port) 

I 

J-5458 

t 

CARTER 4-BARREL SPECIAL TOOLS 

J-1388 

J- 818-5 

J-1388 

J-5458 

J-5496 

J-5923 

Choke Un loader Gauge 

. Fast Idle Cam Clearance Gauge 

Float level Gauge 

. Bending Tool 

Holding Stand 

J-5923 

J-5496 

J-818-5 

SER VICE CRAFTSMAN NEWS REFERENCE 

News 

Year 

News 

No. 

Page 

No. 

Subject

Carter WCFB 4 - Pontiac Custom Safari 55 56 & 57

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