Polaris 550 Shift 136 Owner's Manual For Maintenance And Safety page 59

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 of 0_ to +20_ F. (-18_ to -7_ C). Carburetors 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 74 for more
information.
NOTICE: 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 Supplement.
Tip: It's the owner's responsibility to ensure that the correct jets are installed in
the machine for a geographical area. Be very careful 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.
OPERATION
55