2004 Skidoo ZX Series Service Manual, Page 219Get this manual
Section 05 ENGINES (4-TEC) Subsection 01 (TROUBLESHOOTING)
CRANKSHAFT
SYMPTOM UNUSUAL ENGINE NOISE ANDOR VIBRATIONS
CONDITION
TestInspection
NORMAL USE 1Check noise coming from crankshaft areaaCrankshaft bushings are damagedReplace the crankshaft bushings(refer to CRANKSHAFTDRIVE GEARS)bConnecting rod bushings are damagedReplace the connecting rod bushings(refer to CRANKSHAFTDRIVE GEARS)2Check if drive gears are loosenaCrankshaft nut retaining drive gear is looseRetighten retaining nut with recommended torque
ELECTRIC STARTER