2004 Skidoo ZX Series Service Manual, Page 76Get this manual
Section 03 TROUBLESHOOTING Subsection 01 (ENGINE)
SYMPTOM
ENGINE PINGING
CONDITION
TESTINSPECTION
NORMAL USE1Check for proper fuel octane number according to engine typeaToo low fuel octane numberUse appropriate fuel octane number (Refer to Operator's Guide)2Check fuel linesaBent fuel lines (preventing fuel from flowing through)Relocate or replace fuel lines3Check if carburetor(s) is (are) cleanaDirt prevents fuel from flowing throughClean4Check ignition timingaTiming is too advancedAdjust according to specifications (refer to TECHNICAL DATA)5Check compression ratioaCompression ratio is too highReplace inadequate part(s) to obtain manufacturer's recommended compression ratio or use higher grade fuel