2009 Polaris Scrambler 500 4x4 2x4 factory service manual, Page 119Get this manual
FUEL SYSTEMCARBURETION
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 erraticG 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 Fuel pump inoperative Air leak at impulse line Restricted impulse line (kinked, pinched) Intake air leak (throttle shaft, intake ducts, airbox or air cleaner cover) Ruptured vacuum slide diaphragm, Vacuum slide stuck closed or sticky Improper spring Jet needle position incorrect Incorrect pilot screw adjustment RICH MIXTURE Symptoms: Fouls spark plugs, black, sooty exhaust smoke, rough idle, poor fuel economy, engine runs rough misses, poor performance, bog, engine loads up, backfireG Air intake restricted (inspect intake duct) Air filter dirtyplugged Choke plunger sticking, incorrectly adjusted choke Choke cable binding or improperly routed Incorrect pilot airfuel screw adjustment Faulty inlet needle and seat Faulty inlet needle seat O-Ring Float level too high Poor fuel quality (old fuel)