Choke Adjustment - Holley 0-7448 Installation, Tuning, And Adjustment Manual

16. With some air cleaner configurations, it may be necessary to use an air cleaner spacer to provide adequate clearance
between the carburetor and the air cleaner. Holley® offers such a spacer (Holley® P/N 17-13). Depending on the overall
height, obtain the proper length 1/4 x 20 stud and install in the carburetor airhorn. Close the hood slowly to ensure
adequate clearance between the air cleaner stud and the hood.
WARNING: Inadequate clearance between the air cleaner and the throttle lever could result in throttle sticking and
uncontrolled engine speed. Check the clearance between the throttle lever and air cleaner for proper
operation. Check the clearance between the air cleaner and the hood before closing the hood completely.
MAINTENANCE WARNING: Fuel system components, including fuel lines and the carburetor, should be inspected
periodically to assure no fuel leakage and to ensure the soundness of the hoses. Today's clean emissions engines
provide higher temperatures in the engine compartment. These high temperatures promote faster aging of non-
metallic materials.
Hoses that exhibit surface cracks, when bent to 180°, should be replaced. The presence of liquid fuel demands tightening of
fittings, hose replacement, and retorquing of the fuel system component flange nuts. Periodically check the torque on the fuel
bowl screws to 25-30 in./lbs. to assure proper fuel metering.
GENERAL: Some very important factors to optimize efficiency and performance include: Correct engine timing, correct spark
plug gap and heat range, ignition components in good working order, and correct operation of exhaust heat valve.
WARNING: On automatic transmission vehicles only, install the transmission kickdown adjustment screw and black
retaining clip, as correctly indicated. Failure to attend to this detail may result in a sticking wide-open
throttle or dangerous uncontrolled engine speed.

CHOKE ADJUSTMENT:

IMPORTANT: Your Holley® carburetor has been factory wet flowed and calibrated. The "out of the box" settings
should be very close for all adjustments. The following tuning section is included ONLY to aid you in
fine tuning adjustments.
1. If the fast idle RPM is too low or too high for your preferences, SHUT DOWN THE ENGINE! Advance the throttle to wide-
open, exposing the fast idle set screw below the choke housing (See Figure 8).
2. Using a 1/4" open end wrench, turn the screw clockwise to increase the RPM or counterclockwise to decrease the RPM.
The factory setting should give you a 1500-1600 RPM fast idle speed.
NOTE: All vacuum ports must be plugged at this time.
8
Figure 8