Piper Cherokee Six - Page 424

7A-30.
INSTALLATION
AND TIMING
PROCEDURE.
(Timing
Magneto
to
En-
gine.)
Although
only
the
left
magneto
is equipped
with
an
impulse
coupling,
the
timing
procedure,
in
the
following
paragraphs,
is
the
same
for
both
mag-
.....
netos.
a.
Remove
the spark
plug
from
No.
1 cylinder
and place
a thumb
over the
spark
plug
hole.
Rotate
the
crankshaft
in direction of normal rotation until the
compression
stroke
is reached,
this
is
indicated
by
a positive
pressure
inside
the cylinder
tending
to push
the thumb
off the
spark plug hole.
Continue ro-
tatingthecrankshaftindirectionof
nor-
Figure
7A-13. Engine
Timing
Marks
mal
rotation
until
the advance
timing
mark
of 25
°
on
the front
face
of
the starter
ring
gear is
in exact
alignment
with
the
small
hole
located
at the
two
o'clock
position
on
the front
face
of
the starter
housing.
(Refer
to Figure
7A-13.)
NOTE
The advance
timing
mark on the
top face of
the starter
ring
gear is marked
at both
20
°
and 25
°
BTC. Use
only
the 25
°
BTC
mark when
timing the
magnetos
to the en-
gine.
NOTE
If the
crankshaft
is accidently
turned in
the direction
opposite
normal rotation,
repeat
the above
procedure
as accumulated
backlashwill
make the
finaltiming
in-
correct.
b. At this
point, the
engine is
ready for assembly
of
the magnetos.
Remove
the
inspection
plugs
from
both magnetos
and
turn the
drive
shafts in
direction
of
normal
rotation
until the
first painted
chamfered
tooth on
the distributor
gear
is
aligned
in
the center
of the
inspection
window.
(Refer
to Figure
7A-14.)
Being
sure that
the gear
does not
move
from this
position,
installgaskets
and magnetos
on
the engine.
Secure
with washers
and
nuts; tighten
only finger
tight.
Revised: 9/18/78
PIPER CHEROKEE
SIX SERVICE MANUAL
2H4