Spark Plug Fouling Checklist; Troubleshooting - Polaris 2005 SPORTSMAN 500 Servise Manual

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

TROUBLESHOOTING

Engine Turns Over But Fails to Start
No fuel
S
Dirt in fuel line or filter
S
Fuel will not pass through fuel valve
S
Fuel pump inoperative/restricted
S
Tank vent plugged
S
Carb starter circuit
S
Engine flooded
S
Low compression (high cylinder
S
leakage)
No spark (Spark plug fouled)
S
Engine Does Not Turn Over
adjustment or
vibration
filter (main or
Dead battery
S
Starter motor does not turn
S
Engine seized,
S
mechanical failure
Engine Runs But Will Not Idle
Restricted carburetor pilot system
S
Carburetor misadjusted
S
Choke not adjusted properly
S
Low compression
S
Crankcase breather restricted
S
Engine Idles But Will Not Rev Up
Spark plug fouled/weak spark
S
Broken throttle cable
S
Obstruction in air intake
S
Air box removed (reinstall all intake
S
components)
Incorrect or restricted carburetor jetting
S
ETC switch limiting speed
S
Reverse speed limiter limiting speed
S
Carburetor
S
sticking/diaphragm damaged
Incorrect ignition timing
S
Restricted exhaust system
S
Engine Has Low Power
Spark plug fouled
S
Cylinder, piston, ring, or valve wear or
S
damage (check compression)
PVT not operating properly
S
Restricted exhaust muffler
S
Carburetor
S
sticking/diaphragm damaged
Dirty carburetor
S
Piston Failure - Scoring
Lack of lubrication
S
Dirt entering engine through cracks in air
S
filter or ducts
Engine oil dirty or contaminated
S
Excessive Smoke and Carbon Buildup
Excessive piston-to-cylinder clearance
S
Wet sumping
S
Worn rings, piston, or cylinder
S
Worn valve guides or seals
S
Restricted breather
S
Air filter dirty or contaminated
S
Low Compression
Decompressor stuck
S
ENGINE
rusted, or
vacuum slide
vacuum slide
3.53