2004 Skidoo ZX Series Service Manual, Page 218Get this manual
Section 05 ENGINES (4-TEC) Subsection 01 (TROUBLESHOOTING)
CYLINDER AND CYLINDER HEAD
SYMPTOM UNUSUAL ENGINE NOISE ANDOR VIBRATION
CONDITION
TestInspection
NORMAL USE 1Check noise coming from cylinder head areaaFaulty chain tensionerReplace spring andor mechanismbChain guide worn outReplace chain guidecStretched chain andor worn out sprocketsReplace chain and sprocketsdSprocket screws got looseRetighten screws with recommended torqueeHydraulic element inside rocker arm(s) is(are) worn out (valve adjustment)Replace rocker arm(s)fRocker arm screws not tightenedReplace screws and perform the torque procedure (refer to CYLINDER AND CYLINDER HEAD)