Piper Comanche PA-24 Service Manual page 547

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PIPER COMANCHE SERVICE MANUAL
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TIMING MARK
fiGURE 78·13. ENGINE TIMING MARKS
7B41. Traasformer .u.mbly.
•. Check transfor:net .... mbly for cracks in the casi", or for bent or broken mounting bracket •.
Inspect oudet. for damaged or stripped threads.
b. Using an ohmmeter, measure the resistance of the primary and secondary winding of the
transformer assembly. Check. primary resistance between pin of small connector Uld tnnsfom1er hou.sing
Resistance
shall
be 1 to 3 ohms. Measure secondary resistance betWeen pm of large connector and
transformer "ouslng Resistance shall be 10,000 to
14,000
ohms.
c. If transformer i1S5embly
IS
damaged or it fails the rcst, remove four screws securing it to magneto
housmg. Install new transformer assembly Uld torque securing screws to 25·30 lb.
In.
7B ..... 2. Mqnno Timing. (Timing Mapeto to Entdnc) Check each unit for proper magneto rotation before
placUl! eIther unit on the engme. If the magneto is of the correct rounon. rum magneto rotor
shaft
m
direction of rotatlon unell the timing marK on the drive member is a.pproximately in alignment with an
indent on drive end of
magnno
housing. One of the pamted lines on the distributor block should also be In
alignment when viewed through the opening marked '"T" in the housing When VIcwed from drIve end of
the magneto, the painted linc on the right side of disaibutor finger
IS
for clockwise rotanon, and the
painted line on the left side 15 for counterclockwise rotation .. \1.agncto is now
:-';0.
1 cylinder advance firing
posItion.
!'IOTE
The lines on the dinributor finger
lnd
distributor block as described in
prcvlous paragraph. are for reference only Absolutely no adjuscnent of
contact point opening
itom
these marks shall be used
lS
an indication of
proper internal magneto tl1T1ing.
POWER PLANT
REVISED: 4/10/81
2F17