2005 Ski-Doo Tundra, Skandic, Expedition Shop Manual, Page 38Get this manual
Section 02 TROUBLESHOOTING GUIDE Subsection 01 (ENGINE (2-STROKE))
ENGINE (2-STROKE)
The following chart is provided to help diagnose the probable source of troublesIt should be used as guidelineSome causes or corrections may not apply to specific modelSymptom: ENGINE BACKFIRES1Check spark plugs- Carbon accumulation caused by defective spark plug(s)Clean carbon accumulation from piston and cylinder head and install dry properly gapped spark plug(s)2Check ignition timing- Timing is too advancedSet timing according to specifications (refer to TECHNICAL DATA)3Check for erratic sparks- Poor electrical connectionsRepair- Faulty statorReplace defective parts4Check carburetor- Fuel passages obstructedClean carburetor and install new filter(s)- Fuel level too lowAdjust float level according to specifications5Check cooling systemFan-Cooled EnginesLoose fan beltAdjust or replace fan belt (refer to AXIAL FAN COOLING SYSTEM)- Dirty cooling fins or blocked air ductsCleanLiquid-Cooled EnginesLow antifreeze levelAdjust antifreeze levelProceed with leakage test (refer to LIQUID COOLING SYSTEM) and repair as required- Defective tank capReplace cap- Defective thermostatReplace thermostat- Air in systemBleed system