2008 Arctic Cat ThunderCat ATV Service Manual, Page 14Get this manual
Spark Plugs A light brown insulator indicates that plug is correctA white or dark insulator indicates that the engine may need to be serviced or the carburetor (if equipped) may need to be adjustedTo maintain hot, strong spark, keep the plug free of carbon
MufflerSpark Arrester
At the intervals shown in the Periodic Maintenance Chart, clean the spark arrester using the following procedure
! WARNING
Wait until the muffler cools to avoid burns
1Remove the three cap screws securing the spark arrester assembly to the muffler; then loosen and remove the arrester
ATV-0051
! CAUTION
Before removing spark plug, be sure to clean the area around the spark plugDirt could enter engine when removing or installing the spark plug