Checking The Armature (Ptt Motor); Checking The Brush - Yamaha F150A Service Manual

Checking the armature (PTT motor)

1. Check the commutator. Clean using 600-
grit sandpaper and compressed air if
dirty.
2. Measure the commutator diameter "a".
Replace the armature if below specifica-
tion.
a
Motor commutator standard diameter "a":
22.0 mm (0.8661 in)
Wear limit: 21.0 mm (0.8268 in)
3. Measure the commutator undercut "a".
Replace the armature if below specifica-
tion.
Motor commutator standard undercut (ref-
erence data) "a": 1.50 mm (0.0591 in)
Wear limit: 1.00 mm (0.0394 in)
4. Check the armature
Replace if out of specification.
a
for continuity.
9-51
a
b
Armature continuity:
Continuity:
"a"–"b"
No continuity:
"a"–"c"
"a"–"d"

Checking the brush

1. Measure the length of each brush.
Replace if below specification.
Motor brush standard length "a":
10.00 mm (0.3937 in)
Wear limit "b": 3.5 mm (0.14 in)
2. Check the brush and circuit breaker for
continuity. Replace if there is no continu-
ity.
Do not damage the bimetal "1". Other-
wise, the operation of the circuit breaker
could be affected.
PTT motor
d
c
b
a