Piper PA-24 Comanche Service Manual page 425

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PIPER COMANCHE SERVICE MANuAL
e. If it was possible to elecmc::ally disconnect the
saner
from the starter solenoid. the
starnng
vibraror may
be
enc:rgi.zed by tumiftJ the stuter switch on.
f.
If starter wu not electrially removed from staner solenoid, it
is
necessary to connect a jumper
lead from stancr swttch terminal on vibraror to ungrounded terminal on battery. This
will
energize the
StartinJ vibrator.
c. Holdinl the number one cylinder spark plug lead approximately
3/16
to
1/4
inch away from a
load i!'ound. a
series
of hot sparks should
occur.
CAUTION
Grasp
the spark plat
lead
far enouJh away from the connection so
as
not to produce any
dafttcrous
elecmca.l shock.
h. If the spark does not jump the ,ap. check the applied voltale to the starting vibrator. This voluge
should be either 1.2 or 24 volts ckpendinr upon the system being checked.
i,
If voltage
is
correct, check the contact points of the mllDeto. Both
SCtS
of contact p"inu shail be
opened.
J. Reject
aU
units not complyint with the preceding requirementS or which show any visual defects,
1B-48. Spark Plup.
18-49. Removal Of Spuk Plup.
a. Loosen the coupling nut on the harness lad and remove the terminal insulator from the spark plug
barrel well.
NOTE
When withdrawing the ignition cable lead connection from the plug.
care must be taken to pull the Ie:ld straight out and in line with the
center line of the plug barrel; otherwise, a side load will be applied
which frequently results in dam.,e to the burel. insulator and
connector. If the lead C2.ftnot be removed easily
in this
manner, the
resisting contact between the neoprene collar and the barrel insulator
will be broken by a rotary twisang of the collar. Avoid undue distortion
oi the collar and possible side loading of the barrel 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..\s " result. greater torque is frequently reqUired for removing a plug than for
its
instillation.
Accordingly. 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 detriment:ll as in installation, since it cannot
stretch the threaded section. It docs. however imposc " sheanng load on thiS section and may, if
sufficientlv severe. produce a failure in this location.
POWER PlANT
ISSUED: 8/18/72
2
F2~