2000 Yamaha YFM400FWA(M) Factory Service workshop Manual, Page 318Get this manual
IGNITION SYSTEM EB802010
TROUBLESHOOTING IF THE IGNITION SYSTEM FAILS TO OPERATE (NO SPARK OR INTERMITTENT SPARK): Procedure Check: 1.Fuse (main, ignition) 2.Battery 3.Spark plugs 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) Dynamic spark tester: PNYM-34487 Ignition checker: PN90890-06754 Pocket tester: PNYU-03112, 90890-03112
NOTE: Remove the following part(s) before troubleshooting: 1)Seat 2)Fuel tank side panels 3)Front carrier 4)Front fender Use the following special tool(s) for troubleshootingEB802011