BOMBARDIER Johnson 90 Service Manual page 285

POWER TRIM
ANO
TILT - 140
PTT MOTOR
lnspect the commutator surface.
lf surface is gummy or dirty, clean with
400
grit emery paper.
Measure commutator outside diameter.
1®1
Vernier calipers
Commutator outside diameter:
Standard 22 mm (0.87 in)
Service limit 20.4 mm (0.80 in)
lf measurement exceeds service limit, replace armature.
Ensure that the mica (insulator) between the segments is
undercut to specified depth.
Commutator undercut:
Standard 1.6 - 1.9 mm (0.06 - 0.07 in)
Service limit 1.0 mm (0.04 in)
lf undercut is less than service limit, cut to specified depth.
NOTE:
Remove ali particles of mica and metal using compressed
air.
AWARNING
Wear safety glasses when using compressed air.
Brushes
Check the length of each brush.
1rWb
Vernier calipers
Brush length:
Standard
Service limit
9.8 mm (0.39 in)
5.0 mm (0.20 in)
lf brushes are worn down to the service limit, they must be
replaced.
0-ring
lnspect the O-ring between the PTT motor and PTT pump
case. Replace if cuts, nicks or tears are found.
SEGMENT
G)
Commutator undercut
8-41