2001 Arctic Cat ATVs factory service and repair manual, Page 303Get this manual
4Inspect the brush leads for cracks, wear, or frayingIf any of these conditions exist, replace with new brushes and brush springs as set5Inspect the rear cover bushing for wear6Inspect the front cover bearing for wear7Inspect the brass commutator end of the armature for any burned spots or damageIf the commutator is lightly burned or damaged, the armature must be replacedThis is molded commutator and turning it down in lathe should not be attempted ! CAUTION
Buildup in the grooves must be removed to prevent any chance of an electrical arc between individual sections of the commutator
10Inspect the commutator for shorting using multimeter and the following procedureASet the selector to the OHMS positionBTouch the black lead to the armature shaftCUsing the red tester lead, probe the commutator end of the armatureThe meter indicator should not changeIf the indicator shows resistance, the armature is shorted and must be replaced11Inspect the armature for shorting using "growler" and the following procedureAPlace the armature in the "growler BWhile holding metal strip on the armature, rotate the armature an entire revolutionIf the metal strip vibrates at any point on the armature, the armature is shorted and must be replacedFig5-37