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10-40
REMOVAL AND INSTALLATION
OF IDLE LIMITER CAPS
Should the
idle
limiter caps need
replacement because of deformation, muti-
lation or readjustment of idle mixture to
meet
emission
level requirements the
following
procedure must be adhered to
as
the
'thermal conductivity'
type of gas
analyzer
found
in most service
shops
is not
accurate
enough to give the required carbon
monoxide readings.
1. Remove the air cleaner.
2.
Cut the plastic
limiter
cap
and
carefully
pry
apart
and remove
it from
the idle adjustment
screw.
3. Replace
the air
cleaner.
4. Set the ignition
timing to specifica-
tion.
5. Attach
an accurate
tachometer to
the engine.
6. Run the
engine
until the normal
operating
temperature is reached.
7. Adjust the idle air/fuel mixture
screws to give the
best quality idle at 20
R.P.M.
above
the specified speed.
B.
Lean
off
the idle
air/fuel
mixture
screws an equal
amount on each screw by
turning in a clockwise
direction until
the
engine
R.P.M. drops to the specified
idle
speed.
9. Remove the
air cleaner.
l 0. Install the blue plastic
service
limi-
ter cap.
Use
care
not
to
turn the idle mixture
when installing
the
cap.
Position the cap
so that
it
is in
the maximum
counter-
clockwise position
with the tab of the
limiter against the
stop
on the
carburetor.
The idle
mixture
screw will
then be at
the maximum
allowable
outward or rich
setting.
To
install the service limiter
cap,
use a straight forward
push
with
thumb
pressure
or a 3/8"
rod.
11. Replace the air
cleaner
and recheck
the idle speed
to
ensure
that the mixture
screws were
not
accidently
rotated while
fitting
the limiter
caps.
12. Remove the tachometer from the
engine.
FAST IDLE
ADJUSTMENT
The fast idle adjusting
screw
(Fig. 12)
contacts one edge of the fast
idle
cam.
The
cam
permits a faster engine idle
speed
for
smoother
running when the
engine is
cold during choke operation. As
the
choke
plate is moved through its range
of travel
from the closed to the open
position, the fast idle cam pick-up lever
rotates the fast
idle
cam. Each position on
the fast idle cam permits a slower idle rpm
as engine temperature
rises
and choking is
reduced.
GROUP 1
0-FUEL
SYSTEM
Make certain the curb idle speed and
mixture
are adjusted to specification
before attempting to set the fast idle
speed.
1. With
the
engine
operating
temperature normalized (hot), air cleaner
removed and the tachometer attached,
manually rotate the fast idle cam until the
fast idle adjusting screw rests on the
specified
step on the cam.
2.
Turn the fast idle adjusting screw
inward or outward as required to obtain
the
specified
fast idle rpm.
ANTI-STALL
DASHPOT
1. With the engine idle speed and
mixture properly adjusted, and the engine
at normal operating temperature, loosen
the anti-stall dashpot Jock nut.
2.
Hold the throttle in the closed
position and depress the plunger with a
screwdriver blade. Measure the clearance
between the throttle lever
and
the plunger
tip. Turn the anti-stall dashpot in a
direction
to
provide
the
specified
clearance between the tip of the plunger
and the throttle lever. Tighten the locknut
to secure the adjustment.
AUTOMATIC
CHOKE
THERMOSTATIC
SPRING
HOUSING ADJUSTMENT
The
automatic
choke
has
an
adjustment to control its reaction to
engine temperature. By loosening the
clamp screws that retain the thermostatic
spring housing to the choke housing.
The spring housing can be turned to
alter
the
adjustment.
Refer
to
the
specifications for the proper setting.
1. Remove the air cleaner assembly,
heater hose and mounting bracket (if so
equipped) from the carburettor.
2.
Loosen the thermostatic spring
housing clamp retaining screws. Set the
spring
housing
to the specified index mark
and tighten the clamp retaining screws.
3. If other carburettor adjustments
are not required, install the heater hose
and mounting bracket (if so equipped) and
the air cleaner assembly on the carburettor.
ACCELERATING PUMP
STROKE ADJUSTMENT
The stroke should not be changed
from the specified setting.
If
the pump stroke has been
changed
from the specified setting refer to the
following
instructions
to
correct
the
stroke to
specifications.
The primary
throttle
shaft
lever
(overtravel
lever) has 4 holes and the
accelerating pump link has
4
holes (Fig.
13) to control the accelerating pump
FAST IDLE
CAM
B2S9S-A
FIG.12- Fast ldllt Speed Adjustment-
Model 2100-D, 2· V
stroke.
The accelerating pump operating rod
should be in the
specified
hole in the
overtravellever and the
inboard
hole (hole
closets to the pump plunger) in the
accelerating pump link (Fig. 13).
1. To release the rod
from the
retaining
clip,
press the tab end of the
clip
toward the rod; then,
at
the
same
time,
press the rod away from the
clip
until it is
disengaged.
2.
Position
the
clip
over
the
specified hole in the overtravel lever. Press
the ends of the clip together and insert the
operating rod through the
clip
and the
overtravel lever. Release the clip to engage
the rod.
CHOKEPLATEPULLDOWN
AND FAST IDLE CAM
CLEARANCE
Choke
Plate Pulldown
1. Remove the air cleaner,Page
lo-67.
2.
With
the
engine
at
normal
operating temperature, loosen the choke
thermostatic
spring
housing
retainer
screws and
set
the housing 90 degrees in
the rich direction.
3.
Disconnect and remove the choke
heat tube from the
choke
housing
4. Turn the fast idle adjusting screw
outward one full turn.
5.
Start the
engine,
then check for
the specified clearance between the lower
edge of the choke plate and the air horn
wall (Fig. 14).
6.
If
the clearance is not within
specifications,
turn the diaphragm stop
screw
(located on the underside of the
choke
diaphragm
housing) clockwise to
decrease or counterclockwise to increase
the clearance.
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