1999 Ski-Doo Factory Shop Manual Volume Two, Page 63Get this manual
Section 03 TROUBLESHOOTING Subsection 02 (ENGINE)
SYMPTOM CONDITION TestInspection
ENGINE PINGINGNORMAL USE1Check fuel linesaBent fuel lines (preventing fuel from flowing through)Relocate or replace fuel lines2Check if carburetor(s) is (are) cleanaDirt prevents fuel from flowing throughClean3Check ignition timingaTiming is too advancedAdjust according to specifications (refer to TECHNICAL DATA 10)4Check compression ratioaCompression ratio is too highReplace inadequate part(s) to obtain manufacturer's recommended compression ratio or use higher grade fuel