2005-2009 Honda TRX400EX/TRX400X Service Manual, Page 310Get this manual
ELECTRIC STARTER Check for continuity between pairs of commutator barsThere shou ld be continuity
Check for continuity between each commutator bar and the armature shaftThere should be no co ntinuity
Check for continuity between the insulated brush and cable terminalThere should be continuity