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14-22
CARBURETOR-BBS
tion from the setting that gave the highest r.p.m.
reading.
(3) From the highest idle speed setting, turn the
mixture screw clockwise (leaner) until the speed starts
to drop. Turn the screw in the opposite direction
(counter-clockwise) just far enough to recover the
speed that was lost.
T h i s
procedure will assure that the idle has been
set
the leanest mixture possible for smooth idle.
This
setting is very important.
Since the correct speed was originally set using the
speed screw, the speed obtained after finding the
leanest smooth idle setting will probably be too fast.
(4)
Readjust the speed screw to obtain correct idle
speed. Repeat steps 2 and 3 above.
Fast Idle Speed (On the vehicle after
Approximately
500
miles if necessary)
To
set
the fast idle speed on the car, connect a
tachometer to the vehicle, then set the curb idle speed
and proceed as follows:
(1) With the engine running, and the transmission
in the neutral position, open the throttle slightly.
(2)
Close the choke valve about 20 degrees then
allow the throttle to close. Return the choke valve to
the open position.
(3) The fast idle speed adjusting screw should be
contacting the slowest speed step on the fast idle
cam, as shown in (Fig. 19).
(4)
With the engine warmed-up to the normal op-
erating temperature, turn the fast idle speed adjust-
ing screw
in
or
out
to secure
700
r.p.m.
Reposition
the cam and throttle after every screw adjustment to
apply normal throttle closing torque.
FAST IDLE SPEED ADJUSTING , C HOKE
VALVE WIDE OPEN
SCREW
ON
THE SLOWEST
SPEED STEP
OF THE
Fig. 19-Fast
Idle Speed Adjustment lon the vehiclel
Fig. 20-Spring
Stage Choke Adjustment
Spring Staged Choke Adjustment
To check the spring staged choke for correct oper-
ating clearance, refer to (Fig.
20),
then proceed
as
follows
:
(1)
Push on the hub lever with the finger, at the
closed choke position. A small opening should exist
between the shaft and the hub levers,
as
shown in
(Fig. 20).
(2)
Using a drill or gauge, measure the opening. The
opening should be from .010 to
.OM
inches.
(3) If an adjustment is necessary, bend the hub
lever tang until the correct opening has been ob-
tained.
The Float Setting (On the Vehiclel
mounted on the vehicle, proceed as follows:
To check the float setting with the carburetor
(1)
Remove the accelerator pump operating rod.
(2)
Remove two of the long air horn attaching
screws and two short screws, then install the two
short screws in place of the two long screws removed.
This will hold the main body to the throttle body.
Tighten screws securely.
(3) Remove the remaining air horn screws, then
tilt the air horn far enough to disengage the fast idle
cam link from the fast idle cam. Remove the air horn
and gasket.
Check the float setting as follows:
(4) Seat the float fulcrum pin by pressing on the
fulcrum pin retainer.
There should be enough fuel in the bowl to raise
the float so that the lip bears firmly against the nee-
dle. Additional fuel may be admitted by slightly de-
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