Polaris Sportsman 90 - Manual (Page 180)

144
MAINTENANCE
Spark Plugs
The spark plug required for this machine is NGK BP7HS or NGK BPR7HS. Incorrect
spark plug gap can cause the spark plugs to foul. The spark plug gap should be be-
tween 0.6 - 0.7 mm.
The spark plug and its condition is indicative of engine operation. The spark plug firing
end condition should be read after the engine is warmed up and the vehicle is driven
at higher speeds. Immediately check the spark plug for correct color.
1. Normal
The 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.