2001 Yamaha YFM660 Raptor Factory Service Manual, Page 287Get this manual
IGNITION SYSTEM EB802010
TROUBLESHOOTING IF THE IGNITION SYSTEM FAILS TO OPERATE (NO SPARK OR INTERMITTENT SPARK):
Procedure Check: 1.Fuse 2.Battery 3.Spark plug 4.Ignition spark gap 5.Spark plug cap resistance 6.Ignition coil resistance
7.Engine stop switch 8.Main switch 9.Pickup coil resistance 10.Chargingrotor rotation direction detection coil resistance 11.Wiring connection (the entire ignition system)
OTE: Remove the following part(s) before troubleshooting: 1)Seat 2)Front fender Use the following special tool(s) for troubleshooting
Dynamic spark tester: PNYM-34487 Ignition checker: PN90890-06754 Pocket tester: PNYU-03112, 90890-03112