Piper Navajo PA-31 Service Manual page 495

PIPER NAVAJO SERVICE MANUAL
out. If it does, the magneto is properly timed to the engine. If the timing light
does not go out, removal of the magneto for internal timing check and inspection
is recommended.
NOTE
The magneto service instructions in this manual are to cover
minor repairs and timing. For further repairs and adjustments
of the magneto, it is recommended that the latest revision of the
manufacturer's recommended service instructions be followed.
j.
Refer to the latest revision of Lycoming Service Instructions No. 1400 for information
regarding replacement of cam retaining screw.
8-54. REMOVAL OF MAGNETO. Before removing the magneto, make sure mag-
neto switches are off.
a. Remove the harness assembly terminal plate from the magneto.
WARNING
The magneto is not internally grounded; when the
ground lead is disconnected, the magneto is hot. Re-
moving the harness assembly terminal plate first and
installing it last minimizes the danger of starting the
engine accidentally when the ground lead is removed
from the magneto.
b. Disconnect the ground lead and the retard spark lead on the left magneto,
at the magneto.
c. Remove the nuts and washers and draw the magneto from the engine.
8-55.
TIMING PROCEDURE (Internal Timing).
a. Remove the cover to the contact(s), distributor block, etc.
b. To internally time the main contact assembly of either the dual-breaker
magnetos or the single-breaker
magnetos, proceed as follows:
1. Loosen the nut securing the drive plate to the magneto shaft sufficiently
in order to install the Scintilla 11-8465 Rotor Holding Tool under the nut and flat
washer as shown in Figure 8-11. Tighten the nut securely.
2. Remove the timing inspection plug from the top of the magneto.
Turn
rotating magnet to proper neutral position. This position is determined by locating
keyways on drive end of magnet shaft at 12 o'clock with respect to name plate on
housing.
Tighten adjusting knob of 11-8465 Rotor Holding Tool until pressure
Revised: 9/24/81
POWER PLANT
2121