Piper Navajo PA-31 Service Manual page 565

PIPER NAVAJO SERVICE MANUAL
TABLE VIIIB-III. TROUBLESHOOTING CHART (ENGINE)
Trouble
Cause
Remedy
Engine is hard
starting.
Low voltage or de-
fective vibrator.
Measure voltage between
vibrator terminal marked
"IN" and the ground
terminal while operating
starter. There must be
at least 13-volts.
Inoperative or de-
fective vibrator.
Retard contact assem-
bly in magneto not
operating electrically.
Engine may kick back
during cranking due
to advance timing of
ignition.
If voltage is adequate,
listen for buzzing of
vibrator during starter.
If no buzzing is heard,
either the vibrator is
defective or the cir-
cuit from the "Out-
put" terminal on the
vibrator to the retard
contact assembly is open.
Check both "Switch and
Retard" circuits. Also
check for good electrical
ground.
Retard points may not be
closing due to wrong ad-
justment, or may not be
electrically connected
in circuit due to a
poor connection. Inspect
retard points to see if
they close. Check for
proper contact at the
"Switch" and "Re-
tard" leads at magneto
and at the vibrator.
Check wiring.
POWER PLANT Reissued: 10/12/79
2L19