2008 Polaris ATV Sportsman 300 400 H.O. Service Manual, Page 22Get this manual
MAINTENANCE Pilot Screw and Idle Speed Adjustment
12Start engine and warm it up to operating temperature (about 10 minutes)Turn pilot screw in (clockwise) until lightly seatedTurn screw out the specified number of turns
Main Air Filter Cleaning
It is advisable to replace the filter when it is dirtyHowever, in an emergency, it is permissible to clean the main filter if you observe the following practices Never immerse the filter in water since dirt can be transferred to the clean air side of the filter If compressed air is used never exceed pressure of 40 PSIAlways use dispersion type nozzle to prevent filter damage and clean from the inside to the outside
NOTE: Do not tighten the pilot screw forcefully against the seat or the screw andor seat will be permanently damaged
Air FilterPre-Filter Service (300)