2004 Skidoo ZX Series Service Manual, Page 74Get this manual
Section 03 TROUBLESHOOTING Subsection 01 (ENGINE)
SYMPTOM
HIGH ENGINE OPERATING TEMPERATURE
CONDITION
TESTINSPECTION
NORMAL USE11Check if there are leaks at air intake silencer andor engine crankcaseaLeak(s)Repair or replace12Check condition and heat range of spark plugsaMelted spark plug tip or inadequate heat rangeReplace
SYMPTOM