|
| |
TRUCK SERVICE MANUAL
TM 5-4210-230-14&P-1
REASSEMBLY
Fuel Bowls and Metering Blocks
Refer to Fig. 28 for the correct location of the fuel bowl parts.
The primary and secondary fuel bowls and metering blocks
are installed on the main body in the same sequence.
Primary Fuel Bowl and Metering Block:
1. Using special socket SE-1772-1 install new gasket and
power valve assembly in metering body.
2. Install the two main jets using special tool SE-1772-6.
3. Where used, install "0" rings, using petroleum jelly as a
lubricant on accelerator pump fuel transfer tube and install
tube in metering block.
4. Install fuel bowl to metering block gasket to metering
block. Be sure all punchings are removed from gasket and
pump passage and gasket aligns with pump passage in
metering block.
5. Install fuel filter screen, fuel inlet fitting and new fuel inlet
fitting gasket.
6. Lubricate the tip of a new accelerator pump synthetic valve
(where used) with a small amount of petroleum jelly and insert
tip into accelerator pump cavity center hole. Using a pair of
needle nose pliers reach into the fuel bowl and grasp the valve
tip. Pull the valve in until it seats in the pump cavity wall and
cut off the tip at the retaining shoulder.
In some 4150 carburetor fuel pump cavities there will be a
very small bleed hole from the fuel bowl. This bleed hole
allows vapor pressure to escape from the fuel pump cavity
into the fuel bowl. This pressure bleed off prevents fuel spill
over through the fuel pump discharge nozzles. The bleed hole
must be checked to make sure it is not clogged.
7. Where used, check accelerator pump inlet check ball travel
(Fig. 47). Clearance between ball and retainer bar is
specified at .011 to .017". Best operation can be expected
with clearance set at low end of specifications (.011"-.014").
Adjustment is made by bending retainer bar. If adjustment is
necessary, extreme care must be taken to prevent possible
damage to ball and/or seat.
Figure 47 Checking Accelerator Pump Inlet Check Ball
Clearance (Not used on All Carb.)
It is emphasized that the check ball setting mentioned above
is a critical item in obtaining instant pump response to throttle
movement. Ball travel in excess of .017" can easily cause a
lag in fuel injection with consequent engine falter during
throttle opening.
8. Position pump diaphragm spring in recess and install
diaphragm assembly. Note that the flat rivet head faces up.
Place pump diaphragm cover in position making sure the
holes are aligned. Install the four screws and lock washers.
Tighten them alternately to evenly compress the diaphragm.
9. Obtain new "O" ring and using petroleum jelly as a
lubricant slide "O" ring into groove on needle and seat
assembly. Install assembly in fuel bowl. Always use new
gasket between adjusting nut and fuel bowl and also between
lock screw and adjusting nut.
10. Insert fuel inlet baffle in bowl over needle and seat
assembly.
11. Place conical spring on locator of float lever and slide the
float with the spring onto shaft in fuel bowl. Secure with
retainer.
CGES-125-T Page 31
PRINTED IN UNITED STATES OF AMERICA
|
