Armature Testing - Polaris A12MH46AX Service Manual

3. Remove brush plate and brushes. Measure length of
brushes and replace if worn past the service limit.
Replace springs if they are discolored or have
inadequate tension.
NOTE: The electrical input post must stay with the
field coil housing.
4. Inspect surface of
discoloration. See Steps 3-6 of 'Armature Testing'.
Brush Inspection
1. Measure length of each carbon brush.
brush assembly when worn to 5/16" (8 mm) or less.
The brushes must slide freely in their holders.
Brush Length
Limit 5/16" (8 mm)
Brush Replacement
1. Install a new carbon brush assembly in the brush
housing. NOTE: 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 housing.
2. Place a wrap of electrical tape on the threads of the
terminal bolt to prevent O-Ring damage during
reinstallation.
3. Install the O-Ring over the bolt. Make sure the O-ring
is fully seated.
4. Remove the electrical tape and reinstall the two small
phenolic washers, the large phenolic washer, flat
washer, and nut.
commutator for wear
Replace
9923412 - 2012 Sportsman 400/500 and EFI Tractor Service Manual
© Copyright 2011 Polaris Sales Inc.

Armature Testing

1. Remove armature from starter casing.
NOTE: Note order of shims on drive end for reassembly.
2. Inspect surface of commutator.
excessively worn or damaged.
3. Using a digital multitester, measure the resistance
or
between each of the commutator segments. The
reading should be .3 ohms or less.
4. Measure the resistance between each commutator
segment and the armature shaft. The reading should
be infinite (no continuity).
5. Check commutator bars for discoloration.
discolored in pairs indicate shorted coils, requiring
replacement of the starter motor.
6. Place armature in a growler. Turn growler on and
position a hacksaw blade or feeler gauge lengthwise
1/8" (.3 cm) above armature coil laminates. Rotate
°
armature 360 . If hacksaw blade is drawn to armature
on any pole, the armature is shorted and must be
replaced.
ELECTRICAL
Replace if
10
Bars
10.41