GMC 4000 Series Service Manual page 347

Sec. 6M
Page 336
FUEL SYSTEM— GASOLINE ENGINES
Figure 2 5 — Checking Float Level (351M Engine)
of the float to the top of the fuel bowl as typically
shown in figure 25. The gauge has several steps
for use with various carburetors. Refer to "Speci­
fications" for the proper float level adjustment
dimension. Hold the tab on the float firmly against
needle valve when using the gauge. Setting is cor­
rect when the edge of the gauge touches top of the
rib on the float. Use tool (J-4395) to bend float
lever next to float to change the float setting. Use
bending tool as illustrated in figure 26.
After checking the float level, install air horn
and a new gasket. Locate screws, choke control
bracket, and identification tag in original positions.
Connect fast idle link, accelerating pump rod, and
choke wire. Install air cleaner.
305E, 305C, and 351C Engines
Float level on carburetors used on these en­
gines can be checked with gauge (J-8824) or by
G M C S E R V I C E M A N U A L
Figure 2 6 — Typical Use of B en d in g Tool to Set Float Level
Figure 2 7 — Checking Float Level
(305C, 305E, and 351C Engines)
measuring with scale. Air horn assembly must be
removed to check float level.
Use side of gauge as shown in figure 27, and
be sure the gasket is removed. Check float level
as follows:
While holding tab of float firmly against needle
valve, measure from top center of float to top
flange of the main body as shown. Measurement
should be as indicated in "Specifications."
To reset float level, bend float lever next to
float using bending tool (J-4395) as shown in figure
26.
ACCELERATOR PUMP TRAVEL
ADJUSTMENT
351M Engines
Measure the total distance from the point at
top of pump lever travel when throttle lever is
G a u g e (J - 8 8 2 4 )
(U se 3 / 1 6 " Side)
C en ter of Float