2005 Ski-Doo Tundra, Skandic, Expedition Shop Manual, Page 66Get this manual
Section 02 TROUBLESHOOTING GUIDE Subsection 05 (ELECTRICAL SYSTEM)
Symptom: ENGINE IS MISFIRING ERRATIC SPARK AT SPARK PLUG (NORMAL USE)1Verify misfiring by observing flash of stroboscopic timing light; unplug connectors between magnetogenerator and vehicle wiring harness to isolate problemCheck condition of connectors- Defective spark plug(s) andor cable(s)cap(s)Defective electrical system wiring harness andor accessories andignition cut-out switchesCondition of connector terminalsReplace defective parts andor repair damaged wiresReplace defective switch(es)Clean terminals and apply silicone dielectric grease
Symptom: ENGINE IS MISFIRING ERRATIC SPARK AT SPARK PLUG(RIDING IN DEEP
AND THICK SNOW