Arctic Cat Z Series 2006, Operator'S Manual

Page: 45 / 88

44 MAINTENANCE
Adjusting Pilot Air Screw
1. While counting the rotations,
carefully rotate the pilot air
screw clockwise until lightly
seated.
2. Rotate the pilot air screw coun-
terclockwise 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
properly positioned and that the
boot is not “folded” in the air-
intake silencer causing a restric-
tion 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 recommended).

NOTE: Make engine idle adjust-
ment only after the engine has
reached running temperature.

NOTE: If the engine does not
star t 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
s y s t e m f ro m f i r i n g t h e sp a r k
plugs.
ADJUSTING CARBURETORS —
VM-STYLE (Twin)
The carburetors have been cali-
brated at the factory for average
riding conditions; however, alti-
tude, temperature, and general wear
may necessitate certain carburetor
adjustments. Be sure the correct
carburetor main jets for the oper-
ating temperature, altitude, and
type of gasoline are being used
(see Selecting Carburetor Main
Jet(s) section). Since carburetor
adjustments critically affect engine
performance, Arctic Cat recom-
mends that all changes in internal
carburetor calibration and piston
valve synchronization be made by
an authorized Arctic Cat Snowmo-
bile dealer; however, four external
adjustments can be made on each
carburetor. These are the choke
cable travel, piston valves, pilot air
screws, and idle speed screws.
! CAUTION
Do not force a pilot air screw
when rotating it clockwise; dam-
age to the pilot air screw needle
tip will result.
! WARNING
DO NOT stand behind the snow-
m o b i l e o r n e a r t h e ro t a t i n g
track. NEVER run the track at
high speed when the track is
suspended.
! WARNING
If a tachometer is not available,
care must be taken not to adjust
engine idle speed too high.
! WARNING
DO NOT operate the snowmo-
bile when any component in the
throttle system is damaged,
frayed, kinked, worn, or improp-
erly adjusted. If the snowmobile
is operated when the throttle
system is not functioning prop-
e r l y, p e r s o n a l i n j u r y c o u l d
result.