Arctic Cat Sno Pro 120 2011, Service Manual

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4-10
0741-518A

NOTE: If cable free-play gap is not correct, rotate
each swivel adapter an equal amount until recom-
mended free-play is achieved. Each piston valve must
be resting against the tip of its idle speed screw.

NOTE: If throttle cable free-play is incorrect, the car-
buretor safety switches will be activated prematurely
and the engine will not start.
6. Install the air silencer boots making sure they are
properly seated to the carburetor.
Synchronizing Piston Valves

NOTE: Arctic Cat recommends using a suitable car-
buretor synchronizer. If a carburetor synchronizer is
not available, use the following procedure.
1. Move the air silencer boots off the intake bores of the
carburetors.
2. Check to make sure the piston valves start to open at
the exact same moment by placing a thumb and fin-
ger against the valves; then lightly compress the
throttle lever.
3. With slight pressure being applied to the throttle
lever, the piston valves should start to open at the
exact same time. Compress and release the throttle
lever several times to assure accurate determination
of piston valve opening.
4. If a piston valve starts to open before another, rotate
the swivel adapter on the valve which is lifting first
clockwise, just enough to synchronize the valves.

NOTE: Recheck by repeating steps 2-4.
5. Tighten the swivel adapter jam nuts securely. Slide
the rubber throttle cable caps down over the swivel
adapters.

NOTE: There must be free-play in the throttle lever.
6. After synchronization has been attained, install the
air silencer boots over the intake bores of the carbu-
retors.
Pilot Air Screws
1. While counting the rotations, carefully rotate each
pilot air screw clockwise until lightly seated.
TZ107A
2. Rotate each pilot air screw counterclockwise the
same number of turns as noted in step 1 for an initial
setting.
3. Synchronize the oil-injection pump (see Related
Items in this section).
Engine Idle Speed
1. With the snowmobile on a shielded safety stand, start
the engine, release the brake lever lock, and thor-
oughly warm up. Fine-tune each idle speed screw
and each pilot air screw until the engine idles
smoothly at the desired RPM (1500 RPM is recom-
mended).

NOTE: Make engine idle adjustment only after the
engine has reached running temperature. Since the
idle speed screws have not been adjusted, apply
slight throttle pressure to keep the engine running.
Allow engine to warm up for 2-3 minutes.
2. After the engine has been allowed to warm up for 2-3
minutes, adjust engine idle by first rotating the PTO-
side carburetor idle speed screw clockwise until the
tachometer reads 1480 RPM.
3. Rotate the MAG-side carburetor idle speed screw
clockwise until tachometer reads 1500 RPM.
TZ107B
! WARNING
Be sure to tighten the swivel adapter jam nuts securely.
If a swivel adapter jam nut is not tightened, the adjuster
can rotate out of the carburetor cap causing the piston
valve not to return to the full-closed position.
CAUTION
Do not force a pilot air screw when rotating it clock-
wise; damage to the pilot air screw needle tip will
result.
Manual
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