2008 Polaris ATV Predator 50, Sportsman Outlaw 90 Service Manual, Page 107Get this manual
FUEL SYSTEM TROUBLESHOOTING
Fuel StarvationLean Mixture
Symptoms: 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 valve restricted Fuel filter plugged Carburetor vent line(s) restricted Plugged or restricted inlet needle and seat screen or inlet passage Clogged jets or passages Float stuck, holding inlet needle closed or inlet needle stuck Float level too low Intake air leak (throttle shaft, intake ducts, airbox or air cleaner cover) Jet needle position incorrect Incorrect pilot screw adjustment