GM Full-Size Trucks 1980-1987 Repair Guide

Carburetor Adjustments

Print

PRELIMINARY CHECKS (ALL CARBURETORS)



The following should be observed before attempting any adjustments.

  1. Run the engine to normal operating temperature.
  2.  
  3. Check the torque of all carburetor mounting nuts. Also check the intake manifold-to-cylinder head bolts. If air is leaking at any of these points, you will not get a proper adjustment.
  4.  
  5. Check the manifold heat control valve (if used) to be sure that it is free.
  6.  
  7. Check and adjust the choke as necessary.
  8.  
  9. Adjust the idle speed and mixture. If any adjustments are performed that might possibly change the idle speed or mixture, adjust the idle and mixture again when you are finished.
  10.  

ROCHESTER ME



Fast Idle
  1. Check and adjust the idle speed.
  2.  
  3. With the engine at normal operating temperature, air cleaner ON, EGR valve signal line disconnected and plugged and the air conditioning OFF, connect a tachometer.
  4.  
  5. Disconnect the vacuum advance hose at the distributor and plug the line.
  6.  
  7. With the transmission in Neutral, start the engine and set the fast idle cam follower on the high step of the cam.
  8.  
  9. Bend the tank in or out to obtain the fast idle speed.
  10.  

Fast Idle Cam
  1. Check and adjust the fast idle speed.
  2.  
  3. Set the fast idle cam follower on the second step of the cam.
  4.  
  5. Apply force to the choke coil rod and hold the choke valve toward the closed position.
  6.  
  7. Measure the clearance between the lower edge of the choke valve and the inside of the air horn wall.
  8.  
  9. Bend the cam to choke rod to obtain clearance.
  10.  

Choke Unloader
  1. Hold the choke valve down by applying light force to the choke coil lever.
  2.  
  3. Open the throttle valve to wide open.
  4.  
  5. Measure the clearance between the upper edge of the choke valve and the air horn wall. Measure at the lower edge of the choke valve.
  6.  
  7. If adjustment is necessary, bend the tang on the throttle lever.
  8.  

Choke Coil Rod
  1. Place the cam follower on the high step of the cam.
  2.  
  3. Hold the choke valve completely closed.
  4.  
  5. A 0.120 in. plug gauge must pass through the hole in the lever attached to the choke coil housing and enter the hole in the casting.
  6.  
  7. Bend link to adjust.
  8.  

Primary Vacuum Break
  1. Place cam follower on high step of cam.
  2.  
  3. Plug purge bleed hole with masking tape over vacuum break and cover. Not all models will have this hole.
  4.  
  5. Using an outside vacuum source, apply vacuum to primary vacuum break diaphragm until the plunger is fully seated.
  6.  
  7. Push down on the choke valve.
  8.  
  9. Insert a specified gauge between the upper edge of the choke valve and the air horn wall. Measure at the lower edge of the choke valve.
  10.  
  11. Bend vacuum break rod for adjustment.
  12.  
  13. After adjustment, check for binding or interference. Remove tape.
  14.  

Metering Rod Adjustment
  1. Remove metering rod by holding throttle valve wide open. Push downward on metering rod against spring tension, then slide metering rod out of slot in holder and remove from main metering jet.
  2.  
  3. Back out idle stop solenoid-hold throttle valve completely closed.
  4.  
  5. Hold power piston down and swing metering rod holder over flat surface (gasket removed) of bowl casting next to carburetor bore.
  6.  
  7. Insert specified gauge.
  8.  
  9. Bend the metering rod holder as necessary.
  10.  

ROCHESTER 2SE



Float Adjustment

See Figure 1

  1. Remove the air horn from the throttle body.
  2.  
  3. Use your fingers to hold the retainer in place, and to push the float down into light contact with the needle.
  4.  
  5. Measure the distance from the toe of the float (furthest from the hinge) to the top of the carburetor (gasket removed).
  6.  
  7. To adjust, remove the float and gently bend the arm to specification. After adjustment, check the float alignment in the chamber.
  8.  



Click image to see an enlarged view

Fig. Fig. 1: 2SE float adjustment

Pump Adjustment

See Figure 2

  1. With the throttle closed and the fast idle screw off the steps of the fast idle cam, measure the distance from the air horn casting to the top of the pump stem.
  2.  
  3. To adjust, remove the retaining screw and washer and remove the pump lever. Bend the end of the lever to correct the stem height. Do not twist the lever or bend it sideways.
  4.  
  5. Install the lever, washer and screw and check the adjustment. When correct, open and close the throttle a few times to check the linkage movement and alignment.
  6.  

1981 and later models do not require this adjustment.



Click image to see an enlarged view

Fig. Fig. 2: 2SE pump adjustment

Fast Idle Adjustment
  1. Set the ignition timing and curb idle speed, and disconnect and plug hoses as directed on the emission control decal.
  2.  
  3. Place the fast idle screw on the highest step of the cam.
  4.  
  5. Start the engine and adjust the engine speed to specification with the fast idle screw.
  6.  

Choke Coil Lever Adjustment
  1. Remove the three retaining screws and remove the choke cover and coil. On models with a riveted choke cover, drill out the three rivets and remove the cover and choke coil.
  2.  

A choke cover retainer kit is required for reassembly.

  1. Place the fast idle screw on the high step on the cam.
  2.  
  3. Close the choke by pushing in on the intermediate choke lever. The intermediate choke lever is behind the choke vacuum diaphragm.
  4.  
  5. Insert a 0.085 in. drill or gauge into the hole in the choke housing. The choke lever in the housing should be up against the side of the gauge.
  6.  
  7. If the lever does not just touch the gauge, bend the intermediate choke rod to adjust.
  8.  

Fast Idle Cam (Choke Rod) Adjustment

A special angle gauge should be used.

  1. Adjust the choke coil lever and fast idle first.
  2.  
  3. Rotate the degree scale until it is zeroed.
  4.  
  5. Close the choke and install the degree scale onto the choke plate. Center the leveling bubble.
  6.  
  7. Rotate the scale so that the specified degree is opposite the scale pointer.
  8.  
  9. Place the fast idle screw on the second step of the cam. Close the choke by pushing in the intermediate lever.
  10.  
  11. Push on the vacuum break lever in the direction of opening choke until the lever is against the rear tang on the choke lever.
  12.  
  13. Bend the fast idle cam rod at the "U" to adjust angle to specifications.
  14.  

Air Valve Rod Adjustment

See Figure 3

  1. Seat the vacuum diaphragm with an outside vacuum source. Tape over the purge bleed hole if present.
  2.  
  3. Close the air valve.
  4.  
  5. Insert the specified gauge between the rod and the end of the slot in the air valve.
  6.  
  7. Bend the rod to adjust the clearance.
  8.  



Click image to see an enlarged view

Fig. Fig. 3: 2SE air valve rod adjustment

Primary Side Vacuum Break Adjustment
  1. Follow Steps 1-4 of the Fast Idle Cam Adjustment.
  2.  
  3. Seat the choke vacuum diaphragm with an outside vacuum source.
  4.  
  5. Push in on the intermediate choke lever to close the choke valve, and hold closed during adjustment.
  6.  
  7. Adjust by bending the vacuum break rod until the bubble in centered.
  8.  

Secondary Vacuum Break Adjustment
  1. Follow Steps 1-4 of the Fast Idle Cam Adjustment.
  2.  
  3. Seat the choke vacuum diaphragm with an outside vacuum source.
  4.  
  5. Push in on the intermediate choke level to close the choke valve, and hold closed during adjustment. Make sure the plunger spring is compressed and seated, if present.
  6.  
  7. Bend the vacuum break rod at the "U" next to the diaphragm until the bubble is centered.
  8.  

Electric Choke Setting

This procedure is only for those carburetors with choke covers retained by screws. Riveted choke covers are preset and nonadjustable.

  1. Loosen the three retaining screws.
  2.  
  3. Place the fast idle screw on the high step of the cam.
  4.  
  5. Rotate the choke cover to align the cover mark with the specified housing mark.
  6.  

Choke Unloader Adjustment

See Figure 4

  1. Follow Steps 1-4 of the Fast Idle Cam Adjustment.
  2.  
  3. Install the choke cover and coil, if removed, aligning the marks on the housing and cover as specified.
  4.  
  5. Hold the primary throttle wide open.
  6.  
  7. If the engine is warm, close the choke valve by pushing in on the intermediate choke lever.
  8.  
  9. Bend the unloader tang until the bubble is centered.
  10.  



Click image to see an enlarged view

Fig. Fig. 4: 2SE unloader adjustment

Secondary Lockout Adjustment

See Figure 5

  1. Pull the choke wide open by pushing out on the intermediate choke lever.
  2.  
  3. Open the throttle until the end of the secondary actuating lever is opposite the toe of the lockout lever.
  4.  
  5. Gauge clearance between the lockout lever and secondary lever should be as specified.
  6.  
  7. To adjust, bend the lockout lever where it contacts the fast idle cam.
  8.  



Click image to see an enlarged view

Fig. Fig. 5: 2SE secondary lockout adjustment

ROCHESTER M2MC M2ME



Float Adjustment

See Figure 6

The M2ME carburetor is the same as the M2MC except that the choke is now electrically operated.

  1. Remove the air horn from the throttle body.
  2.  
  3. Use your fingers to hold the retainer in place, and to push the float down into light contact with the needle.
  4.  
  5. Gauge from the top of the casting to the top of the float, at a point 3 /16 in. back from the end of the toe of the float (gasket removed).
  6.  
  7. To adjust, remove the float and gently bend the arm to specification. After adjustment, check the float alignment in the chamber.
  8.  



Click image to see an enlarged view

Fig. Fig. 6: M2MC float adjustment

Fast Idle Speed

See Figure 7

  1. Place the fast idle lever on the high step of the fast idle cam.
  2.  
  3. Turn the fast idle screw out until the throttle valves are closed.
  4.  
  5. Turn the screw in to contact the lever, then turn it in two more turns. Check this preliminary setting against the sticker figure.
  6.  



Click image to see an enlarged view

Fig. Fig. 7: M2MC fast idle adjustment on the bench

Fast Idle Cam Adjustment

See Figure 8

  1. Adjust the fast idle speed.
  2.  
  3. Place the cam follower lever on the second step of the fast idle cam, holding it firmly against the rise of the high step.
  4.  
  5. Close the choke valve by pushing upward on the choke coil lever inside the choke housing.
  6.  
  7. Gauge between the upper edge of the choke valve and the inside of the air horn wall.
  8.  
  9. Bend the tang on the fast idle cam to adjust.
  10.  



Click image to see an enlarged view

Fig. Fig. 8: M2MC fast idle cam adjustment

Pump Adjustment

See Figure 9

  1. With the fast idle cam follower off the steps of the fast idle cam, back out the idle speed screw until the throttle valves are completely closed.
  2.  
  3. Place the pump rod in the proper hole of the lever.
  4.  
  5. Measure from the top of the choke valve wall, next to the vent stack, to the top of the pump stem.
  6.  
  7. Bend the pump lever to adjust.
  8.  



Click image to see an enlarged view

Fig. Fig. 9: M2MC pump adjustment

Choke Coil Lever Adjustment

See Figure 10

  1. Remove the choke cover and thermostatic coil from the choke housing.
  2.  
  3. Push up on the coil tang (counterclockwise) until the choke valve is closed. The top of the choke rod should be at the bottom of the slot in the choke valve lever. Place the fast idle cam follower on the high step of the cam.
  4.  
  5. Insert a 0.120 in. plug gauge in the hole in the choke housing.
  6.  
  7. The lower edge of the choke coil lever should just contact the side of the plug gauge.
  8.  
  9. Bend the choke rod to adjust.
  10.  



Click image to see an enlarged view

Fig. Fig. 10: M2MC choke coil lever adjustment

Front Vacuum Break Adjustment
  1. Seat the choke vacuum diaphragm, using an outside vacuum source. If there is an air bleed hole on the diaphragm, tape it over.
  2.  
  3. Remove the choke cover and coil. Rotate the inside coil lever counterclockwise.
  4.  
  5. Check that the specified gap is present between the top of the choke valve and the air horn wall.
  6.  
  7. Turn the vacuum break adjusting screw to adjust.
  8.  

Automatic Choke Coil Adjustment
  1. Place the cam follower on the highest step of the fast idle cam.
  2.  
  3. Loosen the three choke cover retaining screws.
  4.  
  5. Rotate the cover and coil assembly counterclockwise until the choke valve just closes.
  6.  
  7. Align the mark on the choke cover with the specified mark on the housing. Make sure the slot in the lever is engaged with the coil tang. Tighten the cover retaining screws.
  8.  

Unloader Adjustment

See Figure 11

  1. With the choke valve completely closed, hold the throttle valves wide open.
  2.  
  3. Measure between the upper edge of the choke valve and the air horn wall.
  4.  
  5. Bend the tang on the fast idle lever to obtain the proper measurement.
  6.  



Click image to see an enlarged view

Fig. Fig. 11: M2MC unloader adjustment

Air Conditioning Idle Speed-Up Solenoid Adjustment

See Figure 12

  1. With the engine at normal operating temperature and automatic transmissions in drive, manual transmissions in neutral, adjust the curb idle to specifications by means of the idle speed screw (air conditioning off).
  2.  
  3. Turn the air conditioning on and disconnect the compressor clutch electrical lead at the connector. The solenoid should be energized.
  4.  
  5. Open the throttle slightly to allow the solenoid plunger to fully extend.
  6.  
  7. Turn the solenoid screw (plunger) to adjust the engine idle to the specified rpm. See your underhood specifications sticker for proper idle speed.
  8.  



Click image to see an enlarged view

Fig. Fig. 12: M2MC A/C idle speed up solenoid adjustment

ROCHESTER M4ME/M4MC



See Figures 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23 and 24

For carburetor adjustments for the 1980-87 M4ME/M4MC Rochester carburetor, please refer to the following illustrations.



Click image to see an enlarged view

Fig. Fig. 13: M4ME and M4MC float adjustment, 1980 and later



Click image to see an enlarged view

Fig. Fig. 14: M4ME and M4MC pump adjustment, 1980 and later



Click image to see an enlarged view

Fig. Fig. 15: M4ME and M4MC air valve spring adjustment, 1980 and later



Click image to see an enlarged view

Fig. Fig. 16: M4ME and M4MC choke coil lever adjustment, 1980 and later



Click image to see an enlarged view

Fig. Fig. 17: M4ME and M4MC choke valve angle gauge adjustment, 1980 and later



Click image to see an enlarged view

Fig. Fig. 18: M4ME and M4MC choke rod fast idle cam adjustment, 1980 and later



Click image to see an enlarged view

Fig. Fig. 19: M4ME and M4MC vacuum break adjustment information, 1980 and later



Click image to see an enlarged view

Fig. Fig. 20: M4ME and M4MC front vacuum break adjustment, 1980 and later



Click image to see an enlarged view

Fig. Fig. 21: M4ME and M4MC rear vacuum break adjustment, 1980 and later



Click image to see an enlarged view

Fig. Fig. 22: M4ME and M4MC air valve rod adjustment (front), 1980 and later



Click image to see an enlarged view

Fig. Fig. 23: M4ME and M4MC air valve rod adjustment (rear), 1980 and later



Click image to see an enlarged view

Fig. Fig. 24: M4ME and M4MC unloader adjustment, 1980 and later

ROCHESTER E2SE 2-bbl



Float Adjustment

See Figure 25

  1. Remove the air horn from the throttle body.
  2.  
  3. Use your fingers to hold the retainer in place, and to push the float down into light contact with the needle.
  4.  
  5. Measure the distance from the toe of the float (furthest from the hinge) to the top of the carburetor (gasket removed).
  6.  
  7. To adjust, remove the float and gently bend the arm to specification. After adjustment, check the float alignment in the chamber.
  8.  



Click image to see an enlarged view

Fig. Fig. 25: E2SE 2-bbl. float adjustment

Pump Adjustment

See Figure 26

  1. With the throttle closed and the fast idle screw off the steps of the fast idle cam, measure the distance from the air horn casting to the top of the pump stem.
  2.  
  3. To adjust, remove the retaining screw and washer and remove the pump lever. Bend the end of the lever to correct the stem height. Do not twist the lever or bend it sideways.
  4.  
  5. Install the lever, washer and screw and check the adjustment. When correct, open and close the throttle a few times to check the linkage movement and alignment.
  6.  

No pump adjustment is required on 1981 and later models.



Click image to see an enlarged view

Fig. Fig. 26: E2SE 2-bbl. pump adjustment

Fast Idle Adjustment

See Figure 27

  1. Set the ignition timing and curb idle speed, and disconnect and plug hoses as directed on the emission control decal.
  2.  
  3. Place the fast idle screw on the highest step of the cam.
  4.  
  5. Start the engine and adjust the engine speed to specification with the fast idle screw.
  6.  



Click image to see an enlarged view

Fig. Fig. 27: E2SE 2-bbl. fast idle adjustment

Choke Coil Lever Adjustment

See Figure 28

  1. Remove the three retaining screws and remove the choke cover and coil. On models with a riveted choke cover, drill out the three rivets and remove the cover and choke coil.
  2.  

A choke cover retainer kit is required for reassembly.

  1. Place the fast idle screw on the high step of the cam.
  2.  
  3. Close the choke by pushing in on the intermediate choke lever. On front wheel drive models, the intermediate choke lever is behind the choke vacuum diaphragm.
  4.  
  5. Insert a drill or gauge of the specified size into the hole in the choke housing. The choke lever in the housing should be up against the side of the gauge.
  6.  
  7. If the lever does not just touch the gauge, bend the intermediate choke rod to adjust.
  8.  



Click image to see an enlarged view

Fig. Fig. 28: E2SE 2-bbl. choke coil lever adjustment

Air Valve Rod Adjustment

See Figure 29

Refer to the accompanying illustration for this procedure.



Click image to see an enlarged view

Fig. Fig. 29: E2SE 2-bbl. air valve rod adjustment

Primary Side Vacuum Break Adjustment

See Figure 30

Refer to the illustration for this procedure.



Click image to see an enlarged view

Fig. Fig. 30: E2SE 2-bbl. primary vacuum break adjustment

Electric Choke Setting

See Figure 31

This procedure is only for those carburetors with choke covers retained by screws. Riveted choke covers are preset and nonadjustable.

  1. Loosen the three retaining screws.
  2.  
  3. Place the fast idle screw on the high step of the cam.
  4.  
  5. Rotate the choke cover to align the cover mark with the specified housing mark.
  6.  



Click image to see an enlarged view

Fig. Fig. 31: E2SE 2-bbl. choke unloader adjustment

ROCHESTER E4ME AND E4MC QUADRAJET



These 4-bbl carburetors feature an electrically operated mixture control solenoid, and are designed as part of the GM Computer Command Control (C3) system. As with the E2SE 2-bbl, the electric mixture control solenoid is mounted in the float bowl, and is used to control the air/fuel mixture in the primary bores of the carburetor. The plunger in the solenoid is controlled, or pulsed, by electrical signals received from the Electronic Control Module (ECM).

An Idle Speed Control (ISC) assembly, monitored by the ECM, controls engine idle speed. The curb (base) idle is programmed into the ECM and is not adjustable. When the throttle lever is resting against the ISC plunger, the ISC acts as a dashpot on throttle closing. An Idle Speed Solenoid or Idle Load Compensator is used on some models to position the primary throttle valve, providing engine idle speed requirements.

On E4MC models, an Idle Load Compensator (ILC) mounted on the float bowl is used to control curb idle speeds. The ILC used manifold vacuum to sense changes in engine load (the A/C compressor clutch engaged, for example) and compensates by adjusting throttle angle for the curb idle speed. The ILC uses a spring loaded vacuum-sensitive diaphragm whose plunger either extends (vacuum decrease) or retracts (vacuum increase) to adjust throttle angle for curb idle speeds. Both the ISC and ILC are factory adjusted.

Float Level

See Figure 32

With the air horn assembly removed, measure the distance from the air horn gasket surface (gasket removed) to the top of the float at the toe ( 1 /16 in. back from the toe).

Make sure the retaining pin is firmly held in place and that the tang of the float is lightly held against the needle and seat assembly.

Remove the float and bend the float arm to adjust except on carburetors used with the computer controlled systems (E4MC and E4ME). For those carburetors, if the float level is too high, hold the retainer firmly in place and push down on the center of the float to adjust. If the float level is too low on models with the computer controlled system, lift out the metering rods. Remove the solenoid connector screw. Turn the lean mixture solenoid screw in clockwise, counting and recording the exact number of turns until the screw is lightly bottomed in the bowl. Then turn the screw out clockwise and remove. Lift out the solenoid and connector. Remove the float and bend the arm up to adjust. Install the parts, turning the mixture solenoid screw in until it is lightly bottomed, then unscrewing it the exact number of turns counted earlier.



Click image to see an enlarged view

Fig. Fig. 32: E4ME/MC float level adjustment

Accelerator Pump

See Figures 33, 34, 35 and 36

The accelerator pump is not adjustable on computer controlled carburetors (E4MC and E4ME).

  1. Close the primary throttle valves by backing out the slow idle screw and making sure that the fast idle cam follower is off the steps of the fast idle cam.
  2.  
  3. Bend the secondary throttle closing tang away from the primary throttle lever, if necessary, to insure that the primary throttle valves are fully closed.
  4.  
  5. With the pump in the appropriate hole in the pump lever, measure from the top of the choke valve wall to the top of the pump stem.
  6.  
  7. To adjust, bend the pump lever.
  8.  
  9. After adjusting, readjust the secondary throttle tang and the slow idle screw.
  10.  



Click image to see an enlarged view

Fig. Fig. 33: E4ME/MC Accelerator pump adjustment



Click image to see an enlarged view

Fig. Fig. 34: E4ME/MC Fast idle adjustment



Click image to see an enlarged view

Fig. Fig. 35: E4ME/MC Front vacuum break adjustment



Click image to see an enlarged view

Fig. Fig. 36: E4ME/MC Rear vacuum break adjustment

OVERHAUL



See Figures 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47 and 48

Efficient carburetion depends greatly on careful cleaning and inspection during overhaul, since dirt, gum, water, or varnish in or on the carburetor parts are often responsible for poor performance.

Overhaul your carburetor in a clean, dust free area. Carefully disassemble the carburetor, referring often to the exploded views and directions packaged with the rebuilding kit. Keep all similar and look-alike parts segregated during disassembly and cleaning to avoid accidental interchange during assembly. Make a note of all jet sizes.

When the carburetor is disassemble, wash all parts (except diaphragms, electric choke units, pump plunger, and any other plastic, leather, fiber, or rubber parts) in clean carburetor solvent. Do not leave parts in the solvent any longer than is necessary to sufficiently loosen the deposits. Excessive cleaning may remove the special finish from the float bowl and choke valve bodies, leaving these parts unfit for service. Rinse all parts in clean solvent, and blow them dry with compressed air or allow them to air dry. Wipe clean all cork, plastic, leather, and fiber parts with a clean, lint-free cloth.

Blow out all passages and jets with compressed air and be sure that there are no restrictions or blockages. Never use wire or similar tools to clean jets, fuel passages, or air bleeds. Clean all jets and valves separately to avoid accidental interchange.

Check all parts for wear or damage. If wear or damage is found, replace the defective parts. Especially check the following:

  1. Check the float needle and seat for wear. If wear is found, replace the complete assembly.
  2.  
  3. Check the float hinge pin for wear and the float(s) for dents or distortion. Replace the float if fuel has leaked into it.
  4.  
  5. Check the throttle and choke shaft bores for wear or an out-of-round condition. Damage or wear to the throttle arm, shaft, or shaft bore will often require replacement of the throttle body. These parts require a close tolerance of it; wear may allow air leakage, which could affect starting and idling.
  6.  

Throttle shafts and bushings are not included in overhaul kits. They can be purchased separately.

  1. Inspect the idle mixture adjusting needles for burrs or grooves. Any such condition requires replacement of the needle, since you will not be able to obtain a satisfactory idle.
  2.  
  3. Test the accelerator pump check valves. They should pass air one way but not the other. Test for proper seating by blowing and sucking on the valve. Replace the valve as necessary. If the valve is satisfactory, wash the valve again to remove moisture.
  4.  
  5. Check the bowl cover for warped surfaces with a straightedge.
  6.  
  7. Closely inspect the valves and seats for wear and damage, replacing as necessary.
  8.  
  9. After the carburetor is assembled, check the choke valve for freedom of operation.
  10.  

Carburetor overhaul kits are recommended for each overhaul. These kits contain all gaskets and new parts to replace those which deteriorate most rapidly. Failure to replace all parts supplies with the kit (especially gaskets) can result in poor performance later.

Some carburetor manufacturers supply overhaul kits of three basic types: minor repair; major repair; and gasket kits.

After cleaning and checking all components, reassemble the carburetor, using new parts and referring to the exploded view. When reassembling, make sure that all screws and jets are tight in their seats, but do not overtighten as the tips will be distorted. Tighten all screws gradually, in rotation. Do not tighten needle valves into their seats; uneven jetting will result. Always use new gaskets. Be sure to adjust the float level when reassembling.



Click image to see an enlarged view

Fig. Fig. 37: Model 1MEF carburetor shown, model 1ME similar



Click image to see an enlarged view

Fig. Fig. 38: Model 1MEF carburetor parts identification



Click image to see an enlarged view

Fig. Fig. 39: Model 2SE carburetor



Click image to see an enlarged view

Fig. Fig. 40: Model 2SE carburetor parts identification



Click image to see an enlarged view

Fig. Fig. 41: Model E2SE carburetor



Click image to see an enlarged view

Fig. Fig. 42: Model E2SE carburetor parts identification



Click image to see an enlarged view

Fig. Fig. 43: Model E4ME carburetor



Click image to see an enlarged view

Fig. Fig. 44: Model E4ME carburetor parts identification



Click image to see an enlarged view

Fig. Fig. 45: Model M4MC/M4ME carburetor



Click image to see an enlarged view

Fig. Fig. 46: Model M4MC/M4ME carburetor parts identification



Click image to see an enlarged view

Fig. Fig. 47: Model M4MEF carburetor



Click image to see an enlarged view

Fig. Fig. 48: Model M4MEF carburetor parts identification

See Figures 49, 50, 51, 52, 53, 54, 55, 56 and 57



Click image to see an enlarged view

Fig. Fig. 49: Carburetor Specifications Rochester ME (1980-86)



Click image to see an enlarged view

Fig. Fig. 50: Carburetor Specifications Rochester 2SE (1980-82)



Click image to see an enlarged view

Fig. Fig. 51: Carburetor Specifications Rochester M2MC (1980-81)



Click image to see an enlarged view

Fig. Fig. 52: Carburetor Specifications Rochester M4MC-M4ME (1980-82)



Click image to see an enlarged view

Fig. Fig. 53: Carburetor Specifications Rochester E2SE (1983-84)



Click image to see an enlarged view

Fig. Fig. 54: Carburetor Specifications Rochester E4ME (1983-84)



Click image to see an enlarged view

Fig. Fig. 55: Carburetor Specifications Rochester M4MC-M4ME (1985)



Click image to see an enlarged view

Fig. Fig. 56:Carburetor Specifications Rochester M4MC-M4ME (1985) (cont'd)



Click image to see an enlarged view

Fig. Fig. 57: Troubleshooting Basic Fuel System Problems

 
label.common.footer.alt.autozoneLogo