2001 Yamaha YFM660 Raptor Factory Service Manual, Page 179Get this manual

SWINGARM AND DRIVE CHAIN

2.Check: Drive chain Stiffness Clean and lubricate or replace
3.Clean: Drive chain

Wipe Put

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