2012 Sportsman 400/500 and EFI Tractor Service Manual 9923412, Page 170Get this manual
500 EFI FUEL SYSTEM FUEL SYSTEM TROUBLESHOOTING
FUEL STARVATIONLEAN MIXTURE
The correct position of the throttle body idle stop is established and set at the factoryDo not loosen the throttle body idle stop or alter the stop position in any fashionIf the stop is repositioned, the entire throttle body assembly must be replacedSymptoms: Hard start or no start, bog, backfire, popping through intakeexhaust, hesitation, detonation, low power, spark plug erosion, engine runs hot, surging, high idle, idle speed erratic No fuel in tank Restricted tank vent, or routed improperly Fuel lines or fuel injectors restricted Fuel filter plugged Fuel pump inoperative Air leak in system Intake air leak (throttle shaft, intake boot, gasket or grommet) Throttle stop screw tamperingreplace throttle body Failed Sensor or disconnected wiring
POOR IDLE