Carburetor - Arctic Cat 120 sno pro Operator's Manual

CARBURETOR

The carburetor has been calibrated for
average riding conditions; however,
altitude, temperature, and general wear
may necessitate certain carburetor
adjustments. Since carburetor adjust-
ments critically affect engine perfor-
mance, Arctic Cat recommends that
any changes in internal carburetor cali-
bration be made by an authorized Arc-
tic Cat Snowmobile dealer; however,
three external adjustments can be made
on the carburetor. These are the idle
speed screw, pilot air screw, and throt-
tle cable.
Idle Speed Screw
The idle speed screw controls the seat-
ing position of the throttle valve which
in turn determines the proper idle
speed. Rotate the screw clockwise to
increase engine idle speed and counter-
clockwise to decrease engine idle
speed.
Pilot Air Screw
The pilot air screw determines the fuel/
air mixture for idling. To adjust the
pilot air screw, use the following proce-
dure:
1. Carefully rotate the pilot air screw
clockwise until a light "seating
resistance" is felt.
! CAUTION
DO NOT force the pilot air screw
when seating; damage to the pilot
air screw will result.
2. Rotate the pilot air screw counter-
clockwise 1 turn.
3. Start the engine and "fine tune" the
pilot air screw until the engine
idles smoothly.
Throttle Cable
The correct throttle cable adjustment is
when (with the engine OFF) the carbu-
retor throttle is completely open
(against its limit) while the throttle
lever lightly contacts the handlebar
grip. The throttle arm on the carburetor
should also contact the speed control
screw when the throttle lever is
released.
To adjust the throttle cable, use the fol-
lowing procedure:
! WARNING
Do not attempt to adjust the throt-
tle cable with the engine running.
Personal injury could result.
0735-464
1. Loosen the throttle cable wire
binding screw.
2. Pull all slack from the throttle
cable wire and exert slight tension
on the wire.
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