2008 Arctic Cat ThunderCat ATV Service Manual, Page 106Get this manual
Troubleshooting Problem: Spark absent or weak Condition 1Ignition coil defective 2Spark plug defective 3Magneto defective 4ECU defective 5Pick-up coil defective Problem: Spark plug fouled with carbon Condition 1Gasoline incorrect 2Air cleaner element dirty 3Spark plug incorrect (too cold) 4Valve seals crackedmissing 5Oil rings wornbroken Problem: Spark plug electrodes overheat or burn Condition 1Spark plug incorrect (too hot) 2Engine overheats 3Spark plug loose Problem: Magneto does not charge Condition 1Lead wiresconnections shortedlooseopen 2Magneto coils shortedgroundedopen 3Regulatorrectifier defective