5. FUEL SYSTEM MXU 500 IRS CHOKE INSPECTION O-ring Inspection the choke plunger, spring and O- ring for bends, wear or damage. Spring Choke Plunger Lug INSTALLATION Installation is in the reverse order of removal. Make sure the lug on the carburetor into the cutout on the intake pipe. Cutout Cutout Make sure the lug on the carburetor into the cutout on the air cleaner hose. Lug 5-8