2005 Polaris Sportsman 400/500 Service Manual, Page 298Get this manual
ELECTRICAL Brush Length
Brush Length Service Limit: 516 (.8 cm) 3Remove brush plate and brushesMeasure length of brushes and replace if worn past the service limitReplace springs if they are discolored or have inadequate tension4Inspect surface of commutator for wear or discolorationSee Steps 3-6 of armature testing on Page 10.405Install new carbon brush assembly in the brush housingNOTE: Be sure that the terminal bolt insulating washer is properly seated in the housing, and the tab on the brush plate engages the notch in the brush plate housing6Place wrap of electrical tape on the threads of the terminal bolt to prevent O-Ring damage during reinstallation7Install the O-Ring over the boltMake sure the O-ring is fully seated