1999-2002 TRX400EX Fourtrax Service Manual, Page 236Get this manual
17ELECTRIC STARTER SERVICE INFORMATION TROUBLESHOOTING STARTER MOTOR 17-1 17-2 STARTER RELAY SWITCH CLUTCH DIODE 17-9 17-10
SERVICE INFORMATION
GENERAL
Always turn the ignition switch OFF before servicing the starter motorThe motor could suddenly start, causing serio ous injury