Troubleshooting; Spark Plug Fouling; Engine - Polaris 2007 Sportsman 500 EF Service Manual

TROUBLESHOOTING

Spark Plug Fouling

• Spark plug cap loose or faulty
• Choke cable adjustment or plunger/cable sticking
• Foreign material on choke plunger seat or plunger
• Incorrect spark plug heat range or gap
• Carburetor inlet needle and seat worn
• Jet needle and/or needle jet worn or improperly
adjusted
• Excessive carburetor vibration (loose or missing
needle jet locating pins)
• Loose jets in carburetor or calibration incorrect for
altitude/temperature
• Incorrect float level setting
• PVT system calibrated incorrectly or components
worn or mis-adjusted
• Fuel quality poor (old) or octane too high
• Low compression
• Restricted exhaust
• Weak ignition (loose coil ground, faulty coil, stator,
or ETC switch)
• ETC switch mis-adjusted
• Restricted air filter (main or pre-cleaner) or
breather system
• Improperly assembled air intake system
• Restricted engine breather system
• Oil contaminated with fuel
• Restricted oil tank vent

Engine

Engine Turns Over But Fails to Start
• No fuel
• Dirt in fuel line or filter
• Fuel will not pass through fuel valve
• Fuel pump inoperative/restricted
• Tank vent plugged
• Carb starter circuit
• Engine flooded
• Low compression (high cylinder leakage)
• No spark (Spark plug fouled)
Engine Does Not Turn Over
• Dead battery
• Starter motor does not turn
• Engine seized, rusted, or mechanical failure
Engine Runs But Will Not Idle
• Restricted carburetor pilot system
• Carburetor misadjusted
• Choke not adjusted properly
• Low compression
• Crankcase breather restricted
Engine Idles But Will Not Rev Up
• Spark plug fouled/weak spark
• Broken throttle cable
• Obstruction in air intake
• Air box removed (reinstall all intake components)
• Incorrect or restricted carburetor jetting
• ETC switch limiting speed
• Reverse speed limiter limiting speed
• Carburetor vacuum
damaged
• Incorrect ignition timing
• Restricted exhaust system
ENGINE
slide sticking/diaphragm
3.53
3