Cub Cadet 1535 - Page 23

A WARNING
To avoid injury or an accident, engage brake
lock, place transmission in neutral, and make
sure equipment is disengaged before starting
engine to make carburetor adjustments.
A WARNING
Carbon monoxide fumes can be fatal! Do
not make any adjustments to the carburetor
in a confined area such as a storage build¬
ing. Move the tractor outside into the air.
NOTE
The tractor covered in this manual is
equipped with an adjustable carburetor.
The carburetor is adjusted at the factory and under
normal operating conditions it will not require readjust¬
ing. However, if the engine does not operate properly,
what may appear to be a faulty carburetor adjustment
is in many cases a clogged air filter. This possibility
should be ruled out before attempting to readjust car¬
buretor. Refer to "MAINTENANCE" section in this
manual.
To prevent possible damage to the carburetor nee¬
dles, be very careful closing the carburetor needles
before basic adjustments are made. Improper adjust¬
ment of the carburetor may result in engine damage.
PRELIMINARY SETTINGS (See Figure 32.)
Turn both adjusting needles out (counterclockwise)
from the closed position, 1-3/8 turns. Start the engine
and run at half throttle for five to ten minutes to warm
up.
■ ^NOTE
The engine must be warm before making
final settings.
HIGH IDLE FUEL NEEDLE SETTING
Place the throttle into the "FAST" position. Turn the
high idle fuel adjusting needle out (counterclockwise)
Figure 32. Adjustable-Jet Carburetor
1. High Idle Fuel Needle
2. Low Idle Fuel Needle
3. Low Idle Speed
from the preliminary setting until the engine speed
decreases (rich). Note the position of the needle.
Now turn the adjusting needle in (clockwise). The
engine speed may increase, then it will decrease as
the needle is turned iri (lean). Note the position of the
needle.
Set the adjusting needle midway between the rich
and lean settings.
LOW IDLE SPEED SETTING
Place the throttle control into the "IDLE” or "SLOW"
position. Set the idle speed to 1200 RPM (±75 RPM)
by turning the low idle speed adjusting screw in or out.
LOW IDLE FUEL NEEDLE SETTING
Place the throttle into the "IDLE" or "SLOW" position.
Turn the low idle fuel adjusting needle out (counter¬
clockwise) from the preliminary setting until the engine
speed decreases (rich). Note the position of the nee¬
dle.
Now turn the adjusting needle in (clockwise). The
engine speed may increase, then it will decrease as
the needle is turned in (lean). Note the position of the
needle.
Set the adjusting needle midway between the rich
and lean settings.
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