2001 Polaris Sportsman 400-500 DUSE and H.O. Service Manual, Page 42Get this manual
MAINTENANCE
PILOT SCREW ADJUSTMENT
Pilot Screw (Idle Mixture) Adjustment Notes
Do not tighten the pilot screw forcefully against the seat or the screw andor seat will be permanently damagedStart engine and warm it up to operating temperature (about 10 minutes)This is very important step1Turn pilot screw in (clockwise) until lightly seatedTurn screw out the specified number of turnsPilot Screw Adjustment: 2.0 Turns 2Connect an accurate tachometer that will read in increments ofor 50 RPM such as the PET 2100DX (PN 8712100DX) or the PET 2500 (PN 8712500)3Set idle speed to 1200 RPMAlways check throttle cable freeplay after adjusting idle speed and adjust if necessary4Slowly turn mixture screw clockwise using the pilot screw wrench until RPM begins to decrease by 50 RPM or greater5Slowly turn mixture screw counterclockwise until idle speed increases to maximum RPMContinue turning counterclockwise until idle RPM begins to drop6Center the pilot screw between the points in step and 67Re adjust idle speed if not within specificationFRONT (Engine)