Advertisement
PART 20-1- MAINTENANCE OPERATIONS
20-13
4. Pull the choke piston lever
counterclockwise until the gauge is
snug
in the piston slot. Hold the wire
gauge
in
place by exerting light pres-
sure
in a rearward direction on the
choke piston lever. Check the choke
plate clearance
(Pull
down) between
the
lower edge of the choke plate and
the wall of the air horn.
5. To adjust the choke plate clear-
ance,
loosen the hex. head screw (left
hand
thread) on the choke plate shaft
(Fig. 25)
and pry
the
link away irom
the
tapered shaft.
Use
a drill gauge 0.010-inch
under the specified clearance
between the lower edge of the choke
plate and the wall of the air horn.
Hold the choke plate against the
gauge and maintain a light pressure
in a
rearward direction on the choke
lever.
With the choke piston snug against
the
0.036-inch wire gauge and the
choke plate against the drill gauge,
tighten the hex. head screw
(left
hand
thread) on the choke plate shaft.
The use of a 0.010-inch undersize
drill gauge is to allow for tolerances
in the linkage. Use a drill gauge
equal to the size of the specified
clearance to make a final check.
6. Install the gasket and thermo-
static spring
housing on the choke
housing. Install the spring housing
retainer and
screws.
FAST IDLE CAM CLEARANCE
1. Rotate the
spring
housing coun-
terclockwise
(rich
direction) to align
the centre
indeJC
mark on the choke
housing with the index mark on the
spring
housing. Rotate the spring
housing an additional 90 degrees
counterclockwise and tighten the re-
taining
screws.
2. Position the fast idle speed ad-
justing
screw
end on the kickdown
(centre) step
of the fast idle cam.
Check the clearance between the
lower
edge
of
the
choke plate and the
air horn wall. Turn the fast idle cam
adjusting screw inward to increase
the
clearance or outward to de-
crease
·
the clearance. Make sure
the fast idle speed adjusting
screw stays at the kickdown step
of the fast idle cam during the
adjustment.
On the 351-C engine, a two-piece
fast idle lever is used to provide
clearance between the lever and mani-
fold, and a tang on the top lever will
align with the V mark on the cam.
3. Set the thermostatic choke hous-
ing
to the specified index mark and
tighten the retaining screws.
4. If the choke plate clearance and
fast idle cam linkage adjustment was
performed with the carburettor on
the engine, adjust the engine idle
speed and fuel mixture. Adjust the
anti-stall dashpot (if so equipped).
ACCELERATING PUMP STROKE
ADJUSTMENT:
STROMBERG (BV 2)
Do not remove the carburettor
from the engine to adjust the pump
stroke.
To check the pump stroke:-
1. Start the engine and run at idle
to normalise engine temperature.
Set the engine to the correct idle
speed. This
is
important as it gives
the correct closed throttle position.
2. Stop engine and remove air
cleaner assembly and carburettor air
horn.
3.
Measure from the top of the
pump piston stem to the top face
of the carburettor main body with
gasket removed (Fig. 26).
FIG.
26-
Accelerator (6 cyl.)
Pump Adjustment
4. Open throttle wide and again
measure from the top of the pump
piston stem to the top face of the
carburettor main body with gasket
removed.
5. The difference between these
two
measurements
will
be the
length of the pump stroke. This
length should be within the specified
limits with the mean size of the
limits being desirable.
If the measurement is found to
be outside the specified limits, the
pump stroke can be adjusted by
bending the arm (top, horizontal
position) of the pump rod. No more
than
·
h "
to
~~"
adjustment should
be required. Two bends in the arm
will be necessary to keep the hole in
the arm parallel with the pump stem.
6. Return the air horn gasket to
its position and replace the air horn
and air cleaner assembly. The capa-
city of the
accelerator·
pump is
correctly calibrated at the specified
pump stroke and any variation of
this stroke outside the limits given
must result in reduced performance
and economy.
Stromberg WW
Series
With throttle valves fully closed
against their bores
(i.e.
slow idle
adjustment screw backed out clear of
shut throttle lever), and with pump
rod in throttle lever hole specified,
check the external vent washer open-
ing "J" as shown in Fig. 27.
Bend pump rod at point indicated
to obtain
specified
opening.
FIG. 27- Accelerator Pump
Clearance -Stromberg
WW Series
NOTE: Make
sure
choke valve is
held open during above check so that
throttle valves can close fully.
MOTORCRAFT MODEL 2100-D 2V
The stroke should not
be
changed from the specified set-
ting.
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. 28) to control the accelerating
pump stroke.
The accelerating pump operating
rod should be in the specified hole in
the overtravel lever and the inboard
hole
(hole
closest to the pump
plunger) in the accelerating pump
link (Fig.
28).
1. To release the rod from the re-
taining 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 speci-
fied hole in the overtravel lever.
Advertisement
