Service manual

8
Hoses that exhibit surface cracks, when bent to 180°, should be replaced. The presence of liquid fuel demands tightening of
fittings, hose replacement, and re-torquing of the fuel system component flange nuts. Periodically check the torque on the fuel
bowl screws to 25-30 in./lbs. to ensure 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:
ELECTRIC CHOKE:
IMPORTANT: The Ultra Double Pumper™ 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. You can control the choke operation by rotating the choke cap. If the choke comes off too soon, loosen the three screws
and rotate the choke cap counterclockwise one notch at a time, until the choke operation is satisfactory. Rotate the choke
cap clockwise, if the choke comes off too late. After making the final adjustments, start the engine and make sure the
choke plate opens completely.
A. A choke that comes off too soon could exhibit one or more of the following symptoms: stalling, surging, backfiring,
stumbles, or poor vehicle drivability when the vehicle is cold.
B. A choke that comes off too late could exhibit one or more of the following symptoms: black smoke from the tail pipe,
poor drivability when cold, poor gas mileage, misses, or rough idle.
2. If choke operation is unsatisfactory and you have adjusted the choke cap in either direction to with unsatisfactory results,
recheck your positive electrical line connection.
3. If the fast idle RPM is too low or too high for your preferences, TURN THE ENGINE OFF. Advance the throttle to wide-
open, exposing the fast idle set screw below the choke housing (See Figure 8).
4. 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.
Figure 8
5. Return the throttle to the fast idle position, as described in step 2. Restart the engine, and recheck the fast idle RPM.
Repeat steps 2 & 3 until the desired fast idle RPM is met.
Fast idle
speed screw