2006 Honda TRX680 Rincon Factory Service Manual, Page 530Get this manual
ELECTRIC STARTER Check the commutator bars of the armature for discolorationNOTE: Do not use emery or sand paper on the commutatorCOMMUTATOR BARS
Check for continuity between pairs of commutator barsThere should be continuity
prjNTINUITY-
Check for continuity between each commutator bar and the armature shaftThere should be no continuity