2005 Polaris Sportsman 400/500 Service Manual, Page 120Get this manual
FUEL SYSTEMCARBURETION outside this temperature andor altitude rangeThe jetting installed in production is not intended for all altitudes andor temperaturesIn addition, air screwpilot screw adjustments and PVT adjustments may be required to suit operating conditions
CV CARBURETOR SYSTEM FUNCTION
Carburetor Component Function
CARBURETOR JETTING
CAUTION: main jet that is too small will cause lean operating condition resulting in serious engine damageSelect the correct main jet carefully for elevation and temperature according to the ATV specifications charts in Chapter or in the Owner's Safety and Maintenance Manual for each particular modelIMPORTANT: The following guidelines must be followed when establishing main jet setting: 1Select the lowest anticipated temperature at which the machine will be operated2Determine the lowest approximate altitude at which the machine will be operated3Select the correct main jet from the chart in Chapter 14Clutching changes may also be required for changes in elevationRefer to clutching chart in Chapter for recommendations