Piper Cherokee Six - Page 381

a
bad
oil
seal
or
oil
seal
bushing
at
drive
end.
Check
manufacturer's
over-
haul
procedure.
5. Look
for frayed
insulation
or
broken
wire
strands
in leads
in
back
of
magneto.
See
that
terminals
are
se-
cure.
Be
sure
wires
are
properly
po-
-
sitioned.
6. Inspect
capacitor
visually.
If
MEASURE
BODY
possible
test for
leakage,
capacity
and
THICKNESS
HERE
series
resistance.
Remember,
anelec-
trical
failure
of
an
aircraft
capacitor
is
rare.
7.
Adjustment
of
breakers
must
be
correct
for
proper
internal
timing
of
Figure
7-7.
Impulse
Coupling
magneto.
(See
paragraph
7-26.)
8.
Check
if
breaker
cam
is clean
and
smooth,
if
cam
screw
is
tight
(25
in.
lbs.).
If
new
points
are
installed,
blot
a little
oil
on
cam.
9.
Inspect
impulse
coupling
(-21
magneto)
flyweights
for
excessive
loose-
ness
on
the
axles.
Design
couplings
having
.927
inch
thick
body
should
be
check
-
ed
with
1/8
inch
drill.
Couplings
with
.974
inch
thick
body
are
checked
with
a
No.
18 drill.
If drill
fits
between
cam
and
flyweight
the
fit
is
too
loose
and
coupling
should
be
replaced.
(Refer
to Figure
7-7.)
10.
Check
impulse
coupling
for
excess
wear
on
the
contact
edges
of
body
and
flyweights.
11.
Check
that
the
impulse
coupling
flyweight
axle
rivets
are
tight
and
there
are
no
cracks
in
body.
12.
Look
at the
lead
conduits.
A few
broken
strands
won't
hurt,
but
if the
insulation
looks
tired,
you
may
be
in
for
trouble.
The
special
high
temperature
coating,
used
on
light-weight
harnesses,
is
provided
chiefly
for
vibration
resis-
tance
and
mechanical
protection.
The
integrity
of
the
harness
is
not
sacrificed
if
small
areas
of
the
braid
show
peeling
or
flaking
of
this
coating.
13.
Check
the
springs
for
breaks,
corrosion,
or
deformation.
If
possible,
check
continuity
from
block
with
tester
or
light.
14.
Check
insulators
for
cracks,
breaks,
or
evidence
of
"old
age".
Be
sure
they
are clean.
15.
Timing
and
ventilator
plugs.
Ventilator
has
drilled
holes
and
should
be
in
lowest
hole
in
magneto
to
serve
also
as
drain
for
excess
water
or
oil.
Solid
plug
is
used
in
other
hole
- or
in
location
exposed
to
rain
or
water.
POWER
PLANT
Revised:
6/18/76
PIPER
CHEROKEE
SIX
SERVICE
MANUAL
2F9