2006 Polaris FST Touring Owners Manual - Page 105

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. 102