Polaris FST Touring - Manual (Page 105)

102
MAINTENANCE
Spark Plugs
A new engine can cause temporary spark plug fouling due to the
preservative added during the assembly process. Avoid prolonged idle
speeds, which cause plug fouling and carbonization.
CAUTION
Using non-recommended spark plugs can result in serious engine
damage. A spark plug with a heat range too high will always
cause engine damage if the engine is operated in conditions more
severe than intended for that plug. Always use the spark plugs
recommended for your snowmobile.
S
Use recommended spark plugs with the proper gap.
S
Use only resistor-type spark plugs.
S
Torque spark plugs to 18-20 ft. lbs. (24-27 Nm).
Check the spark plug firing end condition after the engine has been
warmed up and the vehicle has been driven at higher speeds. If a plug
is fouled, replace the plug using the tools provided in the tool kit.
WARNING
A hot exhaust system and engine can cause serious burns. Wear
protective gloves when removing a spark plug for inspection.
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
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 throttle body 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 or
use of non-recommended injection oil.