2008 Polaris ATV Outlaw 450/525 Service Manual, Page 177Get this manual
ELECTRICAL 56Inspect surface of commutator for wear or discolorationSee Steps 36 under "Armature Testing"Install new carbon brush assembly in the brush housing54Measure the resistance between each commutator segment and the armature shaftThe reading should be infinite (no continuity)Check commutator bars for discolorationBars discolored in pairs indicate shorted coils, requiring replacement of the starter motorPlace armature in growlerTurn growler on and position hacksaw blade or feeler gauge lengthwise 18" (.3 cm) above armature coil laminatesRotate armature 360oIf hacksaw blade is drawn to armature on any pole, the armature is shorted and must be replaced