Edelbrock 1901 User Manual

Page 1 of 4
©2002 Edelbrock Corporation
Brochure No. 63-0149
Rev. 10/02
FIG. 1
FLOAT
SETTINGS
15/32”
15/32”
25/64”
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 Figure15.
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. REINST
ALL
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
7/8 TURN
7/8 TURN
7/8 TURN
1 TURN
FIG. 5
CHOKE
COIL
LEVER
1/8”
1/8”
1/8”
1/8”
1/8”
FIG. 6
FAST
IDLER
48°
48°
48°
48°
48°
FIG. 7
VACUUM
BREAK
22°
22°
27°
27°
27°
FIG. 9
UN-
LOADER
40°
40°
40°
40°
40°
FIG. 2
PUMP SETTINGS
LEVER DIM.
HOLE
INNER
INNER
INNER
INNER
INNER
13/32”
13/32”
13/32”
13/32”
5/8”
ADJUSTMENT SPECIFICATIONS

Edelbrock 1901 Specifications

General

Type	Carburetor
Model	1901
Brand	Edelbrock
CFM	600
Fuel	Gasoline
Style	Square Bore
Part Number	1901
Number of Barrels	4
Choke	Electric
Choke Type	Electric
Base Plate Material	Aluminum
Throttle Bore Size	1.6875 in
CFM Rating	600 CFM

Summary

Disassemble Carburetor

Pump Lever Removal

Remove pump lever by driving roll pin through far enough to permit release of lever.

Air Horn Screws Removal

Remove air horn screws.

Power Piston Removal

Remove power piston by pressing down and releasing with a snap. Remove power piston spring(s).

Factory-Adjusted Screws

Do not turn or remove factory-adjusted stop screw (APT) or screw in aneroid cover.

Idle Mixture Needles

Turn idle mixture needles clockwise, record turns, then remove.

Choke Cap Disassembly

Disassemble choke cap from housing per Figure 13 (not applicable to remote choke models).

Clean Carburetor

Immersion Cleaning

Soak carb parts in cold immersion type carb cleaner, avoiding rubber/aneroid parts.

Passage Cleaning

Blow out all passages with compressed air.

Power Piston Bore

Pay attention to power piston cleanliness and body casting bore for proper function.

Reassemble and Adjust Carburetor

Intermediate Choke Shaft Seal

Install new intermediate choke shaft seal in float bowl, lip faces outward.

Float Needle Pull Clip

Do not install float needle pull clip into holes in float arm.

Power Piston Installation

Install power piston, pressing plastic retainer into bore until flush.

Accelerator Pump Cup

Carefully remove and install pump cup (with garter spring, if used) on pump head.

Pump Stem Seal

If used, install new pump stem seal and retainer in air horn, lip facing outward.

Air Horn Gasket

Select correct air horn gasket by matching replacement to old gasket.

Air Horn Screws Tightening

Tighten air horn screws in numerical sequence per illustration, torque 32-60 in-lbs.

Choke Cover and Coil

Install choke cover and coil assembly per Figure 15.

Accel. Pump Rod Adjustment

Adjust accelerator pump rod by bending lever on pump rod side.

Dry Float Level Adjustment

Adjust float level by pressing float tang until seated on needle.

Bowl Vent Valve Adjustment

Adjust bowl vent valve by turning hex screw after removing plug.

Air Valve Spring Adjustment

Adjust air valve spring by turning screw until it contacts pin on shaft.

Choke Coil Lever Adjustment

Adjust choke coil lever by pushing up until choke valve is closed.

Fast Idle Cam (Choke Rod) Adjustment

Adjust fast idle cam by bending tang on cam follower.

Front Vacuum Break Adjustment

Adjust front vacuum break by pushing up on inside choke coil lever.

Air Valve Rod Adjustment

Adjust air valve rod by measuring distance between rod and slot in lever.

Unloader Adjustment

Adjust unloader by closing choke valve and pushing up on vacuum break lever.

Secondary Throttle Lock-Out Adjustment

Adjust secondary throttle lock-out by measuring clearance between pin and lever.

Secondary Opening Adjustment

Adjust secondary opening by opening primary throttle until link contacts tang.

Secondary Closing Adjustment

Adjust secondary closing by lever against tang.

Reinstall Carburetor

Adjust Idle Mixture and Speed

Remove & Replace Tamper Resistant Choke Cover

Choke Cover Disassembly

Drill out PO rivet heads to remove choke cap and components.

Choke Cover Reassembly

Place choke cap, rotate clockwise until coil tang engages lever tang.

Model 1903 Choke Cover

Align notch in cover with protrusion on retainer at 2 o'clock position.

Model 1904 Choke Cover

Align notch with casting boss at 2 o'clock position, retain with pop rivets.

Exploded View of Carburetor