2001 Polaris Sportsman 400-500 DUSE and H.O. Service Manual, Page 170Get this manual
FUEL SYSTEMCARBURETION
TROUBLESHOOTING, CONTIdle Too LowChoke cable bending or incorrectly adjustedIdle speed set incorrectlyIdle mixture screw misadjusted or damagedBelt draggingIgnition timing incorrectWorn jet needleneedle jet Erratic Idle&&&&&& Choke cable bending or incorrectly adjusted Throttle cable incorrectly adjusted Air leaks, dirty carburetor passages (pilot circuit) Pilot mixture screw damaged or adjusted incorrectly Tight valves Ignition timing incorrect Belt dragging Dirty air cleaner Engine worn Spark plug fouled Idle speed set incorrectly (speed limiter) Worn jet needleneedle jet