Piper Navajo PA-31 Service Manual page 494

PIPER NAVAJO SERVICE MANUAL
223
NORMAL
POINT IS
SMOOTH AND
FLAT.
SURFACE HAS DULL GRAY
''SANDBLASTED"
APPEARANCE.
MINOR IRREGULARITIES -
SMOOTH ROLLING
HILLS
AND DALES WITHOUT ANY
DEEP PITS
OR HIGH
PEAKS. THIS IS A NORMAL
CONDITION
OF POINT
WEAR.
WELL
DEFINED
MOUND
EXTENDING NOTICEABLY
ABOVE
SURROUNDING
SURFACE. REJECT POINTS.
Figure 8-10. Contact Points
NOTE
No attempt should be made to stone or dress contact
points.
Should contact assembly have bad points or
show excessive wear, the complete contact assembly
should be replaced.
g. Check the condition of the cam follower felt.
Squeeze felt tightly between
thumb and forefinger.
If fingers are not moistened with oil, re-oil using 2 or 3
drops of Bendix 10-391200 lubricant.
Allow approximately30 minutes for felt to
absorb the oil. Blot off the excess with a clean cloth. Too much oil may foul con-
tact points and cause excessive burning.
h. Check the capacitor mounting bracket for cracks or looseness.
Using the
Scintilla 11-1767-1, -2 or -3 Condenser Tester or equivalent, check capacitor
for capacitance,
series
resistance
and leakage.
Capacitance shall be at least
0.30 microfarads.
i. Check magneto to engine timing as follows:
1. Connect Scintilla 11-851 Timing Light or equivalent across the main
contact assembly.
2. Slowly bring the engine up to number one cylinder advance firing posi-
tion as instructed
in paragraph 8-56. At this instant the timing light should go
Reissued: 10/12/79
POWER PLANT
2120