2004 Skidoo ZX Series Service Manual, Page 221Get this manual

Section 05 ENGINES (4-TEC) Subsection 01 (TROUBLESHOOTING)
ENGINE GENERAL
SYMPTOM ENGINE BACKFIRES
CONDITION
TestInspection

• ATV
• Jet Ski
• Outboard Motors
• Personal Watercraft
• Snowmobiles
• Stern Drives