MAINTENANCE
53
2. Rotate the pilot air screw counter-
clockwise the exact number of
rotations ± 1/4 turn from the
seated position for an initial set-
ting.
3. Install the air-intake silencer boot
taking care that the boot is prop-
erly positioned and that the boot
is not “folded” in the air-intake
silencer causing a restriction of
air flow.
Adjusting Engine Idle
Speed
1. With the snowmobile on a
shielded safety stand, start the
engine, release the parking brake,
and thoroughly warm up. “Fine-
tune” the idle speed screw and the
pilot air screw until the engine
idles smoothly at the desired
RPM (1500 RPM is recom-
mended).
NOTE: Make engine idle adjust-
ment only after the engine has
reached running temperature.
NOTE: If the engine does not
start after the carburetor has been
adjusted, repeat steps 2-6 of
Adjusting Piston Valve sub-sec-
tion. If all cable slack is “taken up,”
the throttle/ignition monitor switch
will prevent the ignition system
from firing the spark plugs.
ADJUSTING
CARBURETORS (Twin)
The carburetors have been calibrated
at the factory for average riding condi-
tions; however, altitude, temperature,
and general wear may necessitate cer-
tain carburetor adjustments.
Be sure
the correct carburetor main jets
for the operating temperature,
altitude, and type of gasoline are
being used (see Selecting Carbure-
tor Main Jet(s) section).
Since car-
buretor adjustments critically affect
engine performance, Arctic Cat rec-
ommends that all changes in internal
carburetor calibration and piston valve
synchronization be made by an autho-
rized Arctic Cat Snowmobile dealer;
however, four external adjustments
can be made on each carburetor.
These are the choke cable travel, pis-
ton valves, pilot air screws, and idle
speed screws.
NOTE: Carburetor adjustments
and changing main jets may be
done by the snowmobile owner if
qualified to do so. If the owner
does not feel qualified, take the
snowmobile to an authorized Arc-
tic Cat Snowmobile dealer for this
service. This service is at the dis-
cretion and expense of the snow-
mobile owner.
! WARNING
DO NOT stand behind the snow-
mobile or near the rotating track.
NEVER run the track at high
speed when the track is sus-
pended.
! WARNING
If a tachometer is not available,
care must be taken not to adjust
engine idle speed too high.
! WARNING
DO NOT operate the snowmobile
when any component in the throt-
tle system is damaged, frayed,
kinked, worn, or improperly
adjusted. If the snowmobile is
operated when the throttle system
is not functioning properly, per-
sonal injury could result.
