1997 Ski-Doo Factory Shop Manual Volume Three, Page 28Get this manual
Section 02 TROUBLESHOOTING Sub-Section 02 (ENGINE)
SYMPTOM CONDITION TestInspection
ENGINE PINGING NORMAL USE 1Check fuel linesa.Bent fuel lines (preventing fuel from flowing through)Relocate or replace fuel lines2Check if carburetor(s) is (are) cleana.Dirt prevents fuel from flowing throughClean3Check ignition timinga.Timing is too advancedAdjust according to specifications (refer to TECHNICAL DATA 09)4Check compression ratioa.Compression ratio is too highReplace inadequate part(s) to obtain manufacturer's recommended compression ratio or use higher grade fuel