Polaris 9920183 Owner's Manual For Maintenance And Safety page 127

MAINTENANCE AND LUBRICATION
Spark Plugs
1. Normal
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.
NOTE: The tip should not be white. A white insulator tip indicates overheating, caused
by use of an improper spark plug or incorrect carburetion adjustments.
2. Wet Fouled
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, improper use of the choke, or
incorrect carburetion adjustments.
124