Jetting Guidelines - Polaris TRAIL BOSS 325 2001 Manual

JETTING GUIDELINES

Changes in altitude and temperature affect air density, which is essentially 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.
Carburetors are calibrated for an altitude of 0-3000 ft. (0-900 meters) and ambient temperatures between +40
and +80q F (+5q to +26q C). Carburetors must be re-calibrated if operated outside the production temperature
and/or altitude range. The main jet installed in production is not correct for all altitudes and/or temperatures. In
addition, air screw / pilot screw adjustments may be required to suit operating conditions.
CAUTION:
A main jet that is too small will cause a lean operating condition and may cause serious engine damage.
Select the correct main jet carefully for elevation and temperature according to the charts in the General/
Specifications Chapter, or in the Owner's Safety and Maintenance Manual for each particular model.
PILOT SCREW ADJUSTMENT
NOTE: Maximum engine efficiency and horsepower are directly related to proper carburetor and clutch settings.
The jetting charts should be used as a guideline for selecting optimum jetting for varying temperature and altitude
conditions. Pilot screw adjustment will affect mixture from approximately idle to 1/4 throttle setting. Refer to Mainte-
nance Chapter 2 for complete adjustment procedure, and the following guidelines for minor altitude adjustments.
Pilot Screw
Turn the fuel screw in (clockwise) 1/4 turn for each 30q above 60q F. Turn the fuel screw out (counterclockwise)
1/4 turn for each 30q below 60q F.
MAIN JET SELECTION
IMPORTANT: The following guidelines must be followed when establishing a main jet setting:
1. Select the lowest anticipated temperature at which the machine will be operated.
2. Determine the lowest approximate altitude at which the machine will be operated.
3. Select the correct main jet from the chart.
4. Clutching changes may also be required for changes in elevation. Refer to clutching charts in General /
Specifications Chapter 1 for recommendations.
WARNING
Gasoline is extremely flammable and explosive under certain conditions.
Always stop the engine and refuel outdoors or in a well ventilated area.
Do not overfill the tank. Do not fill the tank neck.
Never start the engine or let it run in an enclosed area. Gasoline powered engine exhaust fumes are poison-
ous and can cause loss of consciousness and death in a short time.
Never drain the float bowl when the engine is hot. Severe burns may result.
Do not smoke or allow open flames or sparks in or near the area where refueling is performed or where
gasoline is stored.
If you get gasoline in your eyes or if you should swallow gasoline, see your doctor immediately.
If you spill gasoline on your skin or clothing, immediately wash it off with soap and water and change clothing.
FUEL SYSTEM/CARBURETION
4.1