38
NOTE: Make engine idle adjust-
ment only after the engine has
reached running temperature. Since
the idle speed screws have not been
fine-tuned, slight throttle pressure
may be necessary to keep the engine
running. Allow engine to warm up for
2-3 minutes.
5. After the engine has been thor-
oughly warmed up, fine-tune the
pilot air screws (equally) and the
idle speed screws (equally) until the
engine runs smoothly.
NOTE: Engine idle should be
within a range of 1600-1700 RPM.
6. Test the throttle control lever by
compressing and releasing it several
times. The lever must return to the
idle position quickly and completely.
Calibrating Main Jets/
Pilot Jets/Jet Needle E-
Clips (Internal)
Altitude, temperature, and the use of oxy-
genated gasoline affect the carburetion
needed for optimum engine performance.
The carburetor main jets must be
changed in conjunction with changes in
operating altitude, oxygenated gasoline
usage, and temperature. Also, the pilot
jets and jet needle E-clip positions may
have to be changed with changes in oper-
ating altitude. To change pilot jets and E-
clip positions, the carburetors must be
removed and disassembled (float cham-
ber, etc.). Arctic Cat highly recommends
that this service be done by an authorized
Arctic Cat Snowmobile dealer only.
NOTE: The following internal car-
buretor calibrations 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 Arctic Cat Snowmobile
dealer for this service. This service
is at the discretion and expense of
the snowmobile owner.
As the ambient temperature rises or as
the snowmobile is operated at a higher
altitude, the main jets must be replaced
with leaner main jets. The original equip-
ment (production) main jets may need to
be changed (depending on the type of
gasoline you are using, your operating
altitude, and temperature). A Carburetor
Jet Chart decal is located on the belt
guard of the snowmobile. It should be
noted that when selecting the proper
main jets, it is better to be too rich rather
than too lean. To change carburetor main
jets, use the following procedure:
! WARNING
DO NOT stand behind the snowmo-
bile or near the rotating 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.
CAUTION
It is important that the pilot air
screws are adjusted equally and that
the idle speed screws are adjusted
equally.
! WARNING
DO NOT operate the snowmobile
when any component in the throttle
system is damaged, frayed, kinked,
worn, or improperly adjusted. If the
snowmobile is operated when the
throttle system is not functioning
properly, personal injury could
result.
CAUTION
For information on altitude opera-
tion, see Varying Altitude Operation
sub-section in the Operating
Instructions section.
Summary of Contents for Bearcat 570 XT
Page 7: ...3 Snowmobile Safety Rules...
Page 67: ...63 NOTES...
