Piper Cherokee Six - Page 387

PIPER
CHEROKEE
SIX
SERVICE
MANUAL
7-28.
SPARK
PLUGS.
7-29.
REMOVAL
OF SPARK
PLUGS.
a.
Loosen
the coupling
nut
on the
harness
lead and
remove
the terminal
in-
sulator
from
the
spark
plug
barrel
well.
NOTE
When withdrawing
the ignition
cable lead
connection
from the
plug,
care
must be
taken
to pull
the lead
straight out
and in line
with the
centerline of
the plug
barrel;
otherwise
a
side load
will
be applied,
which
frequently
results
in damage
to the
barrel
insulator
and
connector.
If
the lead
cannot
be removed
easily
in this
manner,
the resistingcontact
between
the neo-
prene
collar
and the
barrel
insulator
will
be broken
by
a rotary
twisting
of the
collar.
Avoid
undue distor-
tion of the
collar and
possible
side loading
of the bar-
rel insulator.
b. Remove
the
spark
plug from
the engine.
In
the course
of engine
operation,
carbon
and other
combustion
products
will be
deposited
on the
end of the
spark
plug and
will penetrate
the
lower
threads
to some
degree.
As a result,
greater
torque
is
frequently
required
for removing
a plug than
for its
installation.
Ac-
cordingly,
the torque
limitations
given do
not apply
to plug
removal
and sufficient
torque
must be
used to
unscrew
the plug.
The higher
torque
in removal
is
not as
detrimental
as in
installation,
since it
cannot stretch
the threaded
section.
It
does,
however,
impose
a shearing
load on this
section
and may,
if sufficiently
severe,
produce
a
failure in
this location.
NOTE
Torque
indicating
handle should
not be
used for
spark
plug
removal
because
of
the greater
torque
require-
ment.
c. Place spark
plugs
in a tray that
will identify
their
position in
the engine
as
soon
as they are
removed.
POWER
PLANT
Issued:
8/17/72
2F15