53
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.
RMK carburetors are preset to operate at altitudes of 6000-8000 feet
(1800-2400 m) above sea level (see page 72 for more information). Car-
buretors 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.
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. Refer to
your Owner’s Manual Supplement.
It’s the owner’s responsibility to ensure that the correct jets are installed
in the snowmobile 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 encountered.