Piper SEMINOLE PA-44-180, Maintenance Manual

Page: 709 / 881

— Note —
Torque indicating handle should not be used for spark plug removal because of the
greater torque requirement.
3. Place spark plugs in a tray that will identify their position in the engine as soon as they are removed.
— Note —
Spark plugs should not be used if they have been dropped.
4. 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 in the apex just large enough to accommodate the funnel of a
C02 bottle. (Refer to Figure 74-32.) When a seized spark plug cannot be removed by normal means, the
funnel adapter is placed over and around the spark plug. Place the funnel of the C02 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.
5. Do not allow foreign objects to enter the spark plug hole.
INSPECTION AND CLEANING OF SPARK PLUGS.
1. Visually inspect each spark plug for the following non-repairable defects: A. Severely damaged shell or
shield threads nicked up, stripped or cross-threaded. B. Badly battered or rounded shell hexagons. C. Out-
of-round or damaged shielding barrel. D. Chipped, cracked or broken ceramic insulator portions. E. Badly
eroded electrodes worn to approximately 50% of original size.
2. Clean the spark plug as required, removing carbon and foreign deposits.
3. Test the spark plug both electrically and for resistance.
4. Set the electrode gap at 0.015 to 0.018 inches.
INSTALLATION OF SPARK PLUGS.
Before installing spark plugs, ascertain that the threads within the cylinder are clean and not damaged.
1. Apply anti-seize compound sparingly on the threads and install gasket and spark plugs. Torque 360 to 420
inch-pounds.
— CAUTION —
MAKE CERTAIN THE DEEP SOCKET IS PROPERLY SEATED ON THE
SPARK PLUG HEXAGON AS DAMAGE TO THE PLUG COULD RESULT IF
THE WRENCH IS COCKED TO ONE SIDE WHEN PRESSURE IS APPLIED
2. Carefully insert the terminal insulator in the spark plug and tighten the coupling nut.
PA - 4 4 - 1 8 0 / 1 8 0 T
AIRPLANE MAINTENANCE MANUAL
7 4 - 2 2 - 0 3
Page 74-27
Revised: May 15, 1989
3G20
PIPER AIRCRAFT