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Maintenance, Spark plugs – Polaris Scrambler 9921777 User Manual

Page 95

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92

MAINTENANCE

Spark Plugs

Spark Plug Condition

Normal Spark 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 indi-

cates the proper type and heat range for the engine and the service.
The tip should not be flaky and white. A white insulator tip indicates

overheating, caused by use of an improper spark plug or incorrect carbu-

retion adjustments.
Wet Fouled Spark 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, improper use of the choke, or incorrect throt-

tle body/carburetor adjustments.