Troubleshooting-Carburetor Related Causes; Fuel Shut-Off Solenoid; Carburetor Circuits; Float - Kohler Courage SV710 Service Manual

Troubleshooting-Carburetor Related Causes

Condition
Engine starts hard, runs rough, or
stalls at idle speed.
Engine runs rich (indicated by black,
sooty exhaust smoke, misfi ring, loss
of speed and power, governor
hunting, or excessive throttle
opening).
Engine runs lean (indicated by
misfi ring, loss of speed and power,
governor hunting, or excessive
throttle opening).
Fuel leaks from carburetor.
FUEL SYSTEM

Fuel Shut-off Solenoid

Most carburetors are equipped with a fuel shut-off
solenoid. Solenoid is attached to fuel bowl. Solenoid has
a spring-loaded pin that retracts when 12 volts is applied
to lead, allowing fuel fl ow to main jet. When current is
removed, pin extends blocking fuel fl ow.
Below is a simple test, performed with engine off, that
can determine if solenoid is functioning properly:
1. Shut off fuel and remove solenoid from carburetor.
When solenoid is loosened and removed, gas will
leak out of carburetor. Have a container ready to
catch fuel.
2. Wipe tip of solenoid with a shop towel or blow with
compressed air to remove any remaining fuel. Take
solenoid to a location with good ventilation and no
fuel vapors present. You will also need a 12 volt
power source that can be switched on and off.
32 690 01 Rev. G
Possible Cause
Low idle fuel mixture (some models)/
speed improperly adjusted.
Clogged air cleaner.
Choke partially closed during
operation.
Low idle fuel mixture is improperly
adjusted.
Float level is set too high.
Dirt under fuel inlet needle.
Bowl vent or air bleeds plugged.
Leaky, cracked, or damaged fl oat.
Low idle fuel mixture is improperly
adjusted.
Float level is set too low.
Idle holes plugged; dirt in fuel delivery
channels.
Float level set too high.
Dirt under fuel inlet needle.
Bowl vents plugged.
Carburetor bowl gasket leaks.
3. Be sure power source is switched OFF. Connect
4. Turn power source ON and observe pin in center of

Carburetor Circuits

Float

Fuel level in bowl is maintained by fl oat and fuel inlet
needle. Buoyant force of fl oat stops fuel fl ow when
engine is at rest. When fuel is being consumed, fl oat will
drop and fuel pressure will push inlet needle away from
seat, allowing more fuel to enter bowl. When demand
ceases, buoyant force of fl oat will again overcome fuel
pressure, rising to predetermined setting and stop fl ow.
KohlerEngines.com
Adjust low idle speed tab, then adjust
low idle fuel needle.
Clean or replace air cleaner.
Check choke lever/linkage to ensure
choke is operating properly.
Adjust low idle fuel needle (some
models).
Separate carburetor air horn from
carburetor body, adjust fl oat
according to steps outlined in repair
kit installation instructions.
Remove needle; clean needle and
seat and blow with compressed air.
Remove low idle fuel adjusting
needle. Clean vent, ports, and air
bleeds. Blow out all passages with
compressed air.
Submerge fl oat to check for leaks.
Adjust low idle fuel needle (some
models).
Separate carburetor air horn from
carburetor body, adjust fl oat
according to steps outlined in repair
kit installation instructions.
Remove low idle fuel adjusting
needle. Clean main fuel jet and all
passages; blow out with compressed
air.
Adjust fl oat according to repair kit
installation instructions.
Remove needle; clean needle and
seat and blow with compressed air.
Blow out with compressed air.
Replace gasket.
positive power source lead to red lead of solenoid.
Connect negative power source lead to solenoid
body.
solenoid. Pin should retract with power ON and
return to its original position with power OFF. Test
several times to verify operation.
Fuel System
Conclusion
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