Removing Frozen Spark Plug - Piper Navajo PA-31 Service Manual

c. Place spark plugs in a tray
that
234
will identify their position in the engine
as soon as they are removed.
NOTE
Spark plugs should not be
installed
if they have been
dropped.
d. Removal of seized spark plugs in
the cylinder
may be accomplished
by
application of liquid carbon dioxide by
a Conical
metal funnel adapter
with a
hole at the apex just large
enough to
accommodate
the funnel of a CO2 bot-
tle. (Refer to Figure 8-31.)
When a Figure 8-31. Removing Frozen
seized spark plug cannot be removed
Spark Plug
by normal means,
the funnel adapter
is placed over and around the spark plug.
Place the funnel of the CO2 bottle inside the funnel adapter and release
the carbon
dioxide
to chill and contract
the spark plug.
Break the spark plug loose with a
wrench. A warm cylinder
head at the time the carbon dioxide is applied will aid
in the removal of an excessively
seized plug.
e. Do not allow foreign objects to enter the spark plug hole.
8-64.
INSPECTION AND CLEANING OF SPARK PLUG.
a. Visually inspect each spark plug for the following non-repairable
defects:
1. Severely damaged shell or shield threads nicked up, stripped
or cross -
threaded.
2.
Badly battered or rounded shell hexagons.
3.
Out-of-round or damaged shielding barrel.
4. Chipped, cracked
or broken ceramic insulator
portions.
5. Badly eroded electrodes
worn to approximately
50% of original
size.
b.
Clean the spark plug as required,
removing carbon and foreign
deposits.
c. Set the electrode
gap at . 015 to . 018 inches.
d. Test the spark plug both electrically
and for resistance.
8-65.
INSTALLATION OF SPARK PLUGS.
Before installing
spark
plugs, as-
certain that the threads
within the cylinder are clean and not damaged.
a. Apply anti-seize
compound sparingly
on the threads and install gasket and
Reissued: 10/12/79
POWER PLANT
PIPER NAVAJO SERVICE MANUAL
2J11