Mercury 40 Service Manual page 107

CHARGING AND STARTING SYSTEM
14. Measure the armature shaft for deflection. If the armature has greater than 0.002 in.
(0.05 mm) deflection, replace armature.
a -
b -
c -
15. Measure the commutator diameter. Replace if not within specification.
a -
b -
16. Measure the mica undercut of the commutator. Clean out and undercut mica and build
up of brush material to a depth of 0.003 - 0.008 in. (0.2 - 0.8 mm).
a -
b -
Page 2B-20
b
Armature
V-Block
Dial Indicator Gauge
a
b
MIN.
Commutator
Commutator Diameter Wear Limit - 1.22 in. (31.0 mm)
a
Commutator Depth
File (or use commutator cutter)
a
a
c
b
b
90-828631R3 MARCH 1999