Edelbrock 1921 User Manual

Page 1 of 4

Rev. 10/02

FIG. 1

FLOAT

SETTINGS

15/32”

25/64”

19/64”

REPLACEMENT Q-JET CARBURETOR

KIT INSTRUCTIONS

KITS #1920, 1921 & 1990

Performer Models 1901, 1902, 1903,

1904,1905,1906,1910

Please read these instructions carefully before attempting to rebuild your carburetor.

Make sure to refer to your carburetor Installation

Instructions for further information if need be. If you have any questions or problems, do not hesitate to contact our Technical Hotline at: (800) 416-
8628 from 7:00 am to 5:00 pm, Monday through Friday, Pacific Standard Time or e-mail us at: edelbrock@edelbrock.com.

To check kit contents see exploded view of carburetor and parts description on last page. Verify that all parts underlined on
list are in your kit.

Carb Kit contains all necessary parts and instructions to rebuild your Edelbrock Carburetor properly. When similar parts are contained in the Carb Kit,
choose the ones that most closely match the existing parts. Some parts in the kit may not be needed.

1. DISASSEMBLE carburetor use accompanying exploded view as a

guide..

➾Remove pump lever by driving roll pin through far enough to permit

release of lever.

➾Remove air horn screws.
➾Remove power piston by pressing down and releasing with a snap.
➾Remove power piston spring(s).
➾Do Not turn nor remove factory-adjusted stop screw next to power

piston. (APT) Adjustable part throttle.

➾Do Not turn nor remove factory-adjusted screw in aneroid cover.
➾Turn idle mixture needles clockwise and record number of turns

needed to lightly bottom them, for use during reassembly. Remove
needles.

➾Disassemble choke cap from housing per Figure 13 (not applicable

to remote choke models).

2. CLEAN carburetor.

➾Soak the carb parts (except as noted below) in a cold immersion

type carb cleaner.

➾Use mineral spirits or kerosene to clean solenoids, choke cover,

aneroid, float, float bowl inserts, vacuum breaks, seals or other
parts containing rubber. Do not immerse these parts in carb
cleaner.

➾Blowout all passages with compressed air .
➾After a thorough cleaning of all castings and parts, pay particular

attention to the cleanliness of the power piston and the body
casting bore where it is housed. Any sticking of the power valve
will prevent proper fuel control and affect driveability.

3. REASSEMBLE carburetor and ADJUST following sequence illustrated.

➾Refer to model number for specifications. Use figure 1 to find

position of model number

➾Install new intermediate choke shaft seal in float bowl. Lip faces

outward. On Hot Air Choke models, install additional shaft seal in

choke housing. Lip faces float bowl. Disregard for remote choke
models.

➾Do not install float needle pull clip into holes in float arm.
➾Install power piston. Press plastic retainer into bore until flush with

top of float bowl casting.

➾Carefully remove pump cup (with garter spring, if used) from pump

head. Install new cup (with new garter spring, if used) on pump
head.

➾If used, install new pump stem seal and retainer in air horn. Lip

faces toward outside of carburetor. Lightly stake casting around
retainer.

➾Select correct air horn gasket by matching replacement to old

gasket.

➾Tighten air horn screws in numerical sequence per illustration.

Torque screws 32-60 in-lbs.

➾Install the choke cover and

coil assembly per Figure1

Use the cover gasket on hot
air model only (1903). Do
not use the cover gasket on
electric choke model
1904,05,06,10.

4. REINSTALL carburetor to intake

manifold, torque mounting bolts
to 110 in-Ibs.

5. ADJUST idle mixture and speed

according to vehicle manufacturer's specifications.

FIG. 13

CHOKE

SETTINGS

PER

NOTCH

PER

NOTCH

PER

NOTCH

PER

NOTCH

PER

NOTCH

CARB #

1901

(8904S)

1902

(8905S)

1903

(8906S)

1904
1905
1906

(8907S)

1910

(8908S)

FIG. 4

AIR

VALVE

SPRING

7/8 TURN

1 TURN

FIG. 5

CHOKE

COIL

LEVER

1/8”

FIG. 6

FAST

IDLER

48°

FIG. 7

VACUUM

BREAK

FIG. 9

UN-

LOADER

FIG. 2

PUMP SETTINGS

LEVER DIM.
HOLE

INNER

13/32”

5/8”

ADJUSTMENT SPECIFICATIONS