Arctic Cat 2015 ZR 5000 Service Manual page 140

7. Inspect the brass commutator end of the armature for
any discolored spots or damage. If the commutator is
slightly discolored or damaged, the armature must be
replaced. This is a molded commutator and no
attempt to turn it down in a lathe should be
attempted.
CAUTION
Do not use emery cloth to clean the commutator as
emery particles will become imbedded in the brass
commutator resulting in a short circuit. Use only #200
grit sandpaper.
8. Inspect the commutator end of the armature for
buildup in the grooves. Carefully remove any
buildup by undercutting using a thinly ground hack-
saw blade. Do not cut any deeper than the original
groove which can be seen by looking at the end of
the commutator.
9. Using a caliper, measure the undercut. Maximum
undercut groove must be as shown.
5000/9000
7000
CAUTION
Buildup in the grooves must be removed to prevent
any chance of an electrical arc between individual sec-
tions of the commutator.
10. Inspect the commutator for shorting using a multi-
meter and the following procedure.
A. Set the selector to the OHMS position.
B. Touch the black lead to the armature shaft.
C. Using the red tester lead, probe the commutator
end of the armature. The meter indicator should
not change. If the indicator shows resistance, the
armature is shorted and must be replaced.
138
11. Inspect the armature for shorting using a "growler"
and the following procedure.
A. Place the armature in the "growler."
B. While holding a metal strip on the armature,
rotate the armature an entire revolution. If the
metal strip vibrates at any point on the armature,
the armature is shorted and must be replaced.
12. Inspect the ground brushes to make sure they are
properly grounded. Use a multimeter and the follow-
ing procedure.
A. Set the selector to the OHMS position.
B. Touch the black tester lead to a ground brush.
C. Touch the red tester lead to the brush holder
assembly.
 NOTE: If no resistance is indicated, check the
ground connection for tightness and for cleanliness.
If there is still no meter indication, replace the brush
SNO2171
assembly.
ASSEMBLING
1. With the brush assembly secured in a vise, compress
each brush all the way into the housing; then care-
fully push the brush wire over and down to secure
the brush in the fully compressed position.
SNO-382A
 NOTE: The brushes must be fully compressed to
allow enough room to install the armature.
2. Install the armature into the brush assembly; then
using a small needle-nose pliers, carefully move the
brush wires upward allowing the brushes to fully
contact the commutator.
0725-653
ZJ143