Pontiac FIREBIRD 1972 Service Manual page 687

ENGINE FUEL 6B-33
Bowl Cover. Check for warped surfaces with a
straight edge. Small nicks and burrs should be
smoothed down to eliminate air or fuel leakage. Make
sure that idle channels are clean and clear.
Float, Needle and Seat. Because of the wear that
normally occurs in these parts and the necessity of
having a tight seating needle, it is advisable to replace
these parts if the carburetor has been used for consid-
erable mileage. Even if mileage is low, replace these
parts if needle is grooved or seat is damaged.
Low Speed Jets. Test jets by blowing or sucking to
make sure that metering holes are clear. Inspect small
ends for damage which might deform the metering
holes.
Metering Rods, Jets and Spring. Metering rods and
jets are subject to wear in normal use. If carburetor
has been used for considerable mileage, it is advisable
to replace these parts since wear cannot readily be
detected by inspection. If metering rod spring in
vacumeter piston link is distorted or damaged, it
should be replaced since it performs an important
function in keeping wear of metering rods and jets at
a minimum.
Vacumeter Piston. Inspect vacumeter piston and its
cylinder for scoring or roughness. Piston and cylin-
der must be clean and smooth. If piston spring is
distorted, it should be replaced.
Accelerating Pump Parts. Inspect countershaft as-
sembly for wear of shaft and make sure that lever is
tight on countershaft. Inspect throttle connector rod
and holes in throttle shaft arm and pump operating
lever for excessive wear. Inspect pump plunger
leather washer for cracks, creases, turned edges or
other damage. Check holes in plunger shaft and
pump arm, also pump arm link, for excessive wear.
Inspect pump intake ball for corrosion and the re-
tainer for distortion.
Inspect pump check needle and replace it if tapered
end is grooved or scored. Make sure that needle seat
in main body is clean. Blow through each pump jet
to make sure it is clean.
Main Body. If passages in main body appear to be
clogged with carbon and gum to such an extend that
penetration of cleaning solution is doubtful, remove
both nozzle passage rivet plugs using Rivet Extrac-
tor. Do not attempt to remove nozzles or anti-per-
colator plugs from main body under any
circumstances.
After passages are thoroughly cleaned, drive new
rivet plugs securely into body openings, using care to
avoid distortion of plugs or openings.
Throttle Body Parts. Be sure that the idle discharge
Fig. 6 8 - 4 2 Metering Rod and Pump Operating Parts
PUMP PLUNGER ASSEMBLY
F L O A T A N D
LEVER ASM.
M E T E R I N G ROD (21
VACUUM
GASKET
Fig. 6 8 - 4 3 Air Horn Parts
INLET
CHECK
METERING
RFTAlNlNG RING BALL
ROD
JETS
VACUUM
PISTON SPRING
Fig. 6 8 - 4 4 Main Body Parts