Overhaul Carburetor - Briggs & Stratton Vanguard 10V300 Repair Manual

C. Thread second nut onto stud right-side up until it
makes firm contact with the first.
D. Rotating outside nut in a clockwise direction,
tighten stud to specification.
E. Remove hex flange nuts from stud.
F. Repeats steps 9(B) thru 9(E) to install second
stud.

Overhaul Carburetor

Disassembly
NOTE: Consult the Illustrated Parts List to obtain the
correct carburetor overhaul kit.
WARNING
Gasoline is extremely flammable and highly
explosive. Inadequate safety precautions can result
in death or serious injury. Always observe the
following precautions when working with fuel system
components:
• Wear proper eye protection.
• Be sure there is no open flame or potential
ignition sources in the area.
• Keep a dry chemical fire extinguisher on hand in
case of emergencies.
8
• When removing fuel hose, drain plug, float bowl,
sediment bowl, etc., cover with a shop towel to
catch any residual fuel leakage.
• Thoroughly wipe up any spilt fuel immediately.
• Collect any fuel and/or shop towels in approved
containers and dispose of properly.
1. Squeeze tangs and move hose clamp away from
fuel inlet fitting. Remove hose from fitting. For best
results, use Fuel Hose Remover (Part No. 19620).
2. See Figure 121. Remove hex screw (A) with gasket
(B) to release float bowl (C) from carburetor body.
3. Remove hinge pin (D) from pedestals to release float
(E) from carburetor body.
4. Remove needle valve (F) with wireform clip (G) from
tab on float hinge.
5. Remove float bowl O-ring (H) from groove in
carburetor body.
6. Using a small flat blade screwdriver, remove
emulsion tube (I) from center passage in carburetor
body.
7. Remove sediment bowl (J) from fuel shutoff valve.
Remove O-ring (K) and fuel filter screen (L).
80
Cleaning and Inspection
1. Obtain Carburetor Cleaner (Part No. 100042).
NOTE: Remove and set aside all rubber parts or
those that have rubber components, such as the
needle valve, O-rings, and fuel hose, as these can be
damaged by the carburetor cleaner.
2. Inspect carburetor body and float bowl for sediment,
gum or varnish deposits. Spray parts and then wipe
away cleaning solution with a clean cloth. Repeat
step until clean cloth shows no evidence of dirt or
debris.
3. Inspect carburetor body and float bowl for cracks or
other damage. Replace carburetor if either condition
is observed.
4. Locate each fuel and air passageway in the
carburetor body. Look for the brass or bronze beads
in the casting, which point out where the cross
drillings of the passageways are located.
5. Spray carburetor cleaner into the entrance of each
passageway and look for the solution to exit from one
or more passageways.
6. Use carburetor cleaner and compressed air to ensure
that each passageway is clean and open.
NOTE: Avoid use of wires or pointed tools as they
can scratch or damage surfaces, enlarge holes, and
push grit and dirt deeper into carburetor.
7. Look through the emulsion tube while holding it
up to the light. The bore should appear round and
unobstructed. Verify that all orifices at sides are clean
and open. Thoroughly clean with carburetor cleaner
and compressed air.
8. Check emulsion tube passageway for discoloration,
dirt, and debris. Clean passageway with a soft bristle
gun cleaning brush.
9. Use compressed air to clean atmospheric vent holes
and air/fuel jets embedded in the carburetor body.
10. Inspect the needle valve and seat. Check tip of
needle valve for wear or grooves. Check wireform clip
for damage or distortion. Replace parts as necessary.
11. Inspect float for distortion, dents, cracks, or holes.
Submerge float in a glass of hot water to verify that it
is water tight. Replace float if damaged or if it cannot
be adequately cleaned.
12. Spray choke shaft and valve and then wipe using a
clean cloth. Inspect for damage or wear.
13. Spray throttle shaft and valve and then wipe using a
clean cloth. Inspect for damage or wear.
14. Thoroughly dry all parts with compressed air.