Chevrolet 1973 Overhaul Manual page 184

throttle body to bowl attaching screws. Throttle
body and insulator gasket may now be removed
from float bowl.
NOTE: Do not tamper with the idle mixture
needle with a limiter cap unless perform ing
an overhaul or due to needle damage. This
has been set to test requirements by the
manufacturer.
2. No further disassembly of the throttle body is
necessary unless the idle mixture needle is damaged
or the idle channels need cleaning. If necessary to
remove the idle mixture needle, destroy plastic
limiter cap as a new one is provided in the overhaul
kit.
Before removing idle mixture
IMPORTANT:
needle, be certain to count number of turns
to bottom the old idle mixture needle. This is
required so that when it is necessary to install
a new needle, you may bottom the new
needle and then back off the same num ber of
turns it took to bottom the old needle.
3. Remove the idle mixture needle and spring, if
required.
NOTE: Due to the close tolerance fit of
throttle valve in the bore of the throttle body,
do not remove the valve or shaft.
Cleaning and Inspection
The carburetor should be cleaned in a cold immersion
type cleaner.
Fig. M5—Model MV (1 bbl) Passenger Car
1. Thoroughly clean carburetor castings and metal
parts in an approved carburetor cleaner.
2. Blow out all passages in castings with compressed
air. Do not pass drills through jets or passages.
3. Inspect idle mixture needle for damage.
4. Examine float needle and seat assembly for wear.
Install a new factory matched set if worn.
5. Inspect upper and lower casting sealing surfaces for
damage.
6. Inspect holes in levers for excessive wear or out of
round condition. If levers or rods are worn they
should be replaced.
7. Examine fast idle cam for excessive wear or
damage.
8. Check throttle and choke levers and valves for
binds and other damage.
9. Replace filter element.
10. Check all springs for distortion or loss in tension,
replace as necessary.
CARBURETOR ASSEMBLY
Throttle Body
New Part Replacement
If a new throttle body is being replaced, install and
CARBURETORS
Any rubber parts, plastic parts,
CAUTION:
including float, diaphragms, pump plunger,
electric parts and solenoids should not be
immersed in carburetor cleaner.
6 M -5
OVERHAUL MANUAL