2007 Arctic Cat Four-Stroke Factory Service Manual, Page 205Get this manual
4Inspect brush leads for cracks, wear, or frayingIf any of these conditions exist, replace with new brushes along with new 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 discolored spots or damageIf the commutator is slightly discolored or damaged, the armature must be replacedThis is molded commutator and no attempt to turn it down in lathe should be attempted 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 replaced