Cessna 177 SERIES Service Manual

3.
Establish that
the magneto is
at the number
should
break at the advanced
firing position
of num-
one firing
position.
It is
possible
for the timing
ber
one cylinder.
Loosen
mounting
nuts
slightly and
mark
to be visible
while
firing position
is
180 degrees
rotate
magneto
case
to cause the
contacts
to break
at
from number
one firing
position.
the correct
position.
Tighten
mounting
nuts.
9.
After tightening
magneto
mounting
nuts,
re-
NOTE
check
timing. Make
sure both
magnetos are
set to
fire at
the same
time. Remove
timing
equipment,
It is necessary
to "spark"
the magneto
to
install spark
plugs and
connect spark
plug leads
and
establish
the correct
firing position.
The
ignition
switch leads.
outlet plate with
the spark plug leads
must
be
installed.
Hold
number
one spark
plug
NOTE
lead (refer
to figure 11-4)
close to magneto
case.
or ground
the magneto
and
hold
the
Beginning
with
the number
one
outlet,
the
number
one spark
plug
lead close
to a good
magneto
fires
at each successive
outlet
in
ground.
Rotate
impulse
coupling
(left mag-
a counterclockwise
direction,
looking
at
neto)
or drive
coupling
(right
magneto)
in
the
outlets.
Connect
number
one magneto
normal
direction
of rotation
until
a spark
outlet
to number
one
cylinder
spark
plug
occurs
at this
lead.
(Impulse
coupling
lead, number
two outlet
to the
next
cylin-
pawls
must
be depressed
to turn
magneto
der
to fire,
etc.
Engine
firing
order
is
shaft in
normal
direction
of
rotation.
)
listed
in paragraph
11-12.
Turn coupling
or drive coupling
backwards
a few
degrees,
until
timing
mark
is center-
b. BENDIX
S-1200
SERIES.
The
magneto
must
be
ed in ventilating
plug
hole
and install
timing
installed
with
its timing
marks
correctly
aligned,
pin
(or 0.
093 inch
6-penny
nail)
through
hole
with number
one
cylinder
on
its compression
stroke
in bottom
of
magneto
next
to flange
and
into
and
with
the number
one
piston
at
its advanced
firing
mating
hole in
the rotor
shaft.
This
locks
position.
Refer to
paragraph
11-12
for
the advanced
the magneto
approximately
in
firing
posi-
firing
position
of number
one piston.
To
locate
the
tion while
installing
on the
engine.
compression
stroke
of
number one
cylinder,
remove
the lower spark
plug from number
2, 3 and 4 cylin-
4. If timing
pin
is not
used,
keep timing
mark
ders.
Place
the thumb
of
one hand
over
the spark
centered
in ventilating
plug
hole
during
magneto
in-
plug
hole of
number
one cylinder
and rotate
crank-
stallation.
shaft in
the direction
of normal
rotation
until
the
5.
Be
sure magneto
gasket
(right
magneto),
mag-
compression
stroke
is
indicated
by positive
pressure
neto
adapter
and gaskets
(left magneto)
are
in place
inside
the cylinder
lifting
the thumb
off
the spark
plug
and that
the
engine
is in
the correct
firing
position,
hole.-
After
the compression
stroke
is
attained,
lo-
then install
magneto
approximately
at the
angle
noted
cate number
one
piston
at its
advance
firing
position.
during
removal.
tighten
mounting
nuts
finger
tight.
Locating
the
advanced
firing
position
of number
one
piston may be obtained
by rotating the
crankshaft op-
NOTE
posite
to its
normal
direction
of rotation
until
the
piston is approximately
30 degrees before
top dead
Remove
timing
pin
(or nail)
from
magneto,
center
(BTC)
on the
compression
stroke
of
number
if
installed.
Be
sure
to remove
this
pin
one
cylinder.
Then
rotate
crankshaft
slowly
in nor-
before
rotating
propeller.
mal
direction
of
rotation
to
align
the timing
mark
on
the FORWARD
face
of the starter
ring gear
with the
6. Connect
a timing
light
to the
capacitor
(pri-
drilled
hole
in
the forward
end of
the starter,
making
mary
lead)
terminal
at
the rear
of
the magneto
and
sure
the
final
movement
of
the ring
gear
is in
the
to a
good
ground.
direction
of
normal
rotation.
7. Rotate propeller
opposite to normal
direction
of rotation
a few
degrees
(approximately
5 degrees)
NOTE
to
close
magneto
contact
points.
An
accurate
top center
indicator
which
NOTE
screws
into
a spark
plug
mounting
hole,
and a pendulum
pointer
mounted on a
Do
not rotate
propeller
back
far enough
360-degree
timing
disc may
also
be used
to engage
impulse
coupling,
or
propeller
to locate
the
advanced
firing
position.
will
have
to be rotated
in
normal direction
The timing
disc
should be
adapted
to fit
of
rotation
untii impulse
coupling
releases
over
the
end of the
propeller
spinner
in
on the
left
magneto.
then
again
backed-up
such a
manner
that
it may
be rotated
as
to
a few
degrees
before
the
firing
position.
necessary.
In
all cases,
it
must be
definitely determined
that the
number
8. Slowly
advance
propeller
(tap
forward
with
one cylinder
is
at the correct
firing
po-
minute
movements
as firing
position
is
approached)
sition
and
on the
compression
stroke,
in
normal
direction
of rotation
until timing
light
indi-
when
the engine
is
turned
in its
normal
cates
position
at
which
contacts
break.
The contacts
direction
of
rotation.
11-24 Change 2

Cessna 177 SERIES Specifications

General

Manufacturer	Cessna
Engine Type	Piston
Wingspan	35 ft 6 in (10.82 m)
Seating Capacity	4
Number Built	4, 295
Engine	Lycoming O-360
Horsepower	180 hp
Maximum Takeoff Weight	2, 500 lb (1, 134 kg)