77
OPERATION
Carburetion
Jetting Guidelines
Changes in altitude and temperature affect air density, which is the
amount of oxygen available for combustion. In low elevations and cold
temperatures, the air has more oxygen. In higher elevations and higher
temperatures, the air is less dense.
The carburetors are calibrated for an altitude of 0-2000 ft. (0-600 m) and
ambient temperatures between -10_ to +10_ F. (-23_ to -12_ C). Carbu-
retors must be re-calibrated if the snowmobile is operated outside this
production temperature and/or altitude range. The main jet installed in
production is not correct for all altitudes and/or temperatures. See page
96 for more information.
NOTE: It's the owner's responsibility to ensure that the correct jets are
installed in the machine for a geographical area. Be very care-
ful when jetting down in warm weather. As the weather turns
colder it will be necessary to re-jet upward to prevent engine
damage. When selecting the proper main jet always use the
lowest elevation and temperature that is likely to be encoun-
tered.
CAUTION
A main jet that's too small will cause a lean operating condition and may
cause serious engine damage. Jet the carburetors carefully for elevation and
temperature according to the jetting charts in your Owner's Manual Supple-
ment.