1999-2004 Honda TRX400EX FourTrax Service Manual, Page 118Get this manual

CYLINDERPISTON -
Make sure that the piston pin clips are seated securelyDo not align the piston pin clip end gap with the piston cutout
CYLINDER INSTALLATION

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