2004 John Deer Buck Utility ATV 500, 500EX and 500EXT Service Manual, Page 67Get this manual
Start engine and allow it to warm then adjust idle speed to specifications by turning idle speed screw clockwise to increase engine speed or counterclockwise to decrease it Carburetor Side:
Refer to specificationsRemove carburetor side coverUsing thumb, release tension on throttle leverWith long nose pliers, rotate cable end bushing so that cable aligns with throttle lever recess, then lift cable endSee next photo
Adjust idle speed to 1100 rpm 100Turn the pilot screw clockwise until engine rpm decreases and note that positionTurn the pilot screw counterclockwise until engine rpm decreasesSet the pilot screw midway between those positions and then, open 34 of turnIf idle speed changes after adjusting the pilot screw, readjust the idle speed screw to 1100 rpm 100