1987-2009 Yamaha ATV YFM350X Warrior Raptor Service Manual, Page 241Get this manual
IGNITION SYSTEM TROUBLESHOOTING
IF IGNITION SYSTEM SHOULD BECOME INOPERATIVE (NO SPARK OR INTERMITTENT SPARK) Procedure Check; 1Spark plug 2Ignition spark gap 3Spark plug cap resistance 4Ignition coil resistance 5Main switch NOTE: -Remove the following parts before troubleshooting1) Headlight unit assembly 4) Fuel tank cover 2) Seat 5) Front fender 3) Front panel 6) Fuel tank -Use the following special tools in this troubleshooting Pocket Tester: YU-03112