2004 Skidoo Tundra Skandic Series Service Manual, Page 65Get this manual
Section 03 TROUBLESHOOTING Subsection 02 (ENGINE)
SYMPTOM CONDITION TestInspection ENGINE BACKFIRESNORMAL USE1Check spark plugs
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 model
aCarbon 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 timingaTiming is too advancedSet timing according to specifications (refer to TECHNICAL DATA)3Check carburetoraFuel passages obstructedClean carburetor and install new filter(s)bFuel level too lowAdjust float level according to specifications4Check cooling system