Bulk-tin 9D-7 August, 1951 Model
"BB" Page 10
ROCHESTER PRODUCTS, DIVISION OF GENERAL MOTORS, ROCHESTER, NEW
YORK
BOWL DISASSEMBLY
1. Remove pump return spring and intake ball
from pump well.
NOTE:
Hold pump outlet guide while removing inlet ball.
2. Carefully remove pump screen from
bowl.
3. Invert the bowl and remove pump discharge
spring guide, spring, and ball.
4 Upend
carburetor bowl (be careful to let the heat tube hang over the end of the
flat surface) and remove four throttle
body attaching screws. The throttle body and gasket may now be removed.
THROTTLE BODY DISASSEMBLY
1. Remove idle adjusting needles and
springs,
2. Remove idle and fast idle screws from throttle
lever.
NOTE: Do not remove
throttle valves from throttle body.
Due to the close tolerance fit of
the throttle valve, and the fact that the idle discharge holes are drilled
in relation to the throttle valve in the closed position, the throttle
body and valve should be replaced as a complete assembly when wear is
noted at the throttle valve, shaft, or throttle body bore.
3. Loosen screw and remove fast idle
cam.
NOTE: It is not necessary to remove choke suction tube from
throttle body.
CLEANING OF
PARTS
1. Thoroughly clean carburetor castings and
metal parts in carburetor cleaning solvent. CAUTION: Choke coil and housing and pump
plunger should not be immersed in solvent. Clean pump plunger in clean gasoline
only.
2. Blow all passages in castings dry with
compressed air and blow off all parts until they are dry.
CAUTION: Do not pass drills or
wires through calibrated jets or passages as this may enlarge orifice and
seriously affect carburetor calibration.
3. Clean filter screens for dirt or lint. If
they are distorted or remain plugged, replace.
INSPECTION
OF
PARTS
l. Check floats for dents or wear
at hinge pin holes. Shake float to check for leaks. Replace if
necessary.
2. Examine float needle and seat. If grooved
replace with a factory tested and matched float needle, seat and gasket
assembly.
3. Check choke shaft for wear in the bores. If
worn excessively replace part.
4. If throttle shaft or valves appear loose
due to wear, replace throttle body assembly.
5. Inspect holes in pump and throttle levers.
If worn out of round they should be replaced.
6. Inspect idle adjusting needles for burrs or
ridges. Replace if necessary.
