Polaris Sportsman 450 2021 Owner's Manual page 137

MAINTENANCE
SPARK PLUG INSPECTION
Spark plug condition is indicative of engine operation. Check the spark plug
firing end condition after the engine has been warmed up and the vehicle has
been driven at higher speeds. Immediately check the spark plug for correct
color.
CAUTION
A hot exhaust system and engine can cause burns. Wear protective gloves
when removing a spark plug for inspection. Allow engine to cool before
removing spark plug wire.
1. Rotate the spark plug cap 1/4 turn and pull it off the spark plug.
2. Rotate the spark plug counter-clockwise to remove it.
3. Reverse the procedure for spark plug installation. Torque to specification.
NORMAL PLUG
The normal insulator tip is gray, tan or light brown. There will be few combustion
deposits. The electrodes are not burned or eroded. This indicates the proper
type and heat range for the engine and the service.
The tip should not be white. A white insulator tip indicates overheating, caused
by use of an improper spark plug or incorrect throttle body adjustments.
WET FOULED PLUG
The wet fouled insulator tip is black. A damp oil film covers the firing end. There
may be a carbon layer over the entire nose. Generally, the electrodes are not
worn. General causes of fouling are excessive oil, use of non-recommended oil
or poor fuel quality.
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