Fuel System; Carburetor Adjustments - Cub Cadet 71 Operator's Manual

FUEL SYSTEM
Illust. 7
Carburetor and fuel strainer.
(International Cub Cadet 71 Tractor)
Illust.7A
Carburetor and fuel strainer.
(Internationol Cub Cadet 102, 122 and 123 Tractors)
CARBURETOR ADJUSTMENTS
For a final check of the high speed adjust-
ment, operate the engine under load and make
any corrections necessary for smooth opera-
tion.
Adjusting the Idle Adjustment Screw
The carburetor is adjusted at the factory
and under normal operating conditions it will
not require readjusting. If this adjustment has
been disturbed for any reason, proceed as
follows:
Adjusting the High-Speed Adjustment Screw After the high speed adjustment screw is
adjusted, it may be necessary to readjust the
idle adjustment screw (1IIusts. 7 and 7A), as each
affects the other.
Turn the high speed adjustment screw (1IIusts.
7 and 7A) counter-clockwise approximately two
turns from the closed position and start the en-
gine.
Close the idle adjustment screw to its seat
by turning it clockwise; then open it one turn.
Start the engine and operate it at fast idling
speed (without any load) until thoroughly warm.
After the engine has reached normal oper-
ating temperature, accelerate the engine and
check its response.
While the engine is running at fast idle
speed, it is advisable to screw in the throttle
stop sc rew (1IIusts.7 and 7 A) a few turns to keep
the engine from stopping when the throttle
lever is moved to the fully retarded "SLOW"
position. The engine will then be idling at a
fairly high speed and the throttle stop screw
can be backed out a little at a time until the
desired idle speed is obtained.
Place the engine under load and turn the
high speed adjustment screw (1IIusts. 7 and 7A) to
the leanest mixture that will allow satisfactory
acceleration and steady governor operation.
If the engine misses and backfires under
load, the high speed mixture is too lean. The
high speed adjustment screw must be turned
counte r- clockwise 1 /4 turn at a time until the
condition is corrected. If the engine misses or rolls while backing
out the throttle stop screw. the idle adjustment
screw may be adjusted in or out until the en-
gine operates smoothly. Speed up the engine
for a few seconds; then recheck the idle ad-
justment. A slight adjustment in or out will
give the smoothest idle.
If the engine shows a sooty exhaust and is
sluggish under load, the high speed mixture is
too rich. The high speed adjustment screw
must be turned clockwise 1 /4 turn at a time
until the condition is corrected.
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