2002 Bombardier Quest 650XT Service Manual, Page 178Get this manual
Section 04 FUEL SYSTEM Subsection 03 (CARBURETOR AND FUEL PUMP)
Carburetor Adjustments
Idle Speed Adjustment 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 itNOTE: Use the digital induction tachometer (PN 529 014 500)CAUTION: Do not attempt to set the idle speed by using the pilot screwRefer to TECHNICAL DATA for idle speed specificationsPilot Screw Adjustment NOTE: The pilot screw is factory pre-setWarm up the engine to operating temperatureTurn the pilot screw clockwise until you hear the engine misses or decreases idle speed, then turn counterclockwise until the engine again misses or decreases idle speedCenter the pilot screw exactly between these two extreme positions then unscrew the pilot screw of 34 turnIf idle speed changes after adjusting the pilot screw, readjust the idle speed screwDiaphragm Installation Carefully, install diaphragm in its original positionMake sure spring is located properly in carburetor cover before screwingNOTE: Check and locate properly the indexation lobThe diaphragm must be installed correctly into the groove on the edge of carburetor housingV04F0KA