Lycoming AIO-320, Operator'S Manual

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LYCOMING OPERATOR’S MANUAL SECTION 5
IO-320 SERIES MAINTENANCE PROCEDURES
SECTION 5
MAINTENANCE PROCEDURES
The procedures described in this section are provided to guide and instruct personnel in performing such
maintenance operations that may be required in conjunction with the periodic inspections listed in the
preceding section. No attempt is made to include repair and replacement operations that will be found in the
applicable Lycoming Overhaul Manual.
1. IGNITION AND ELECTRICAL SYSTEM.
a. Ignition Harness and Wire Replacement –
In the event that an ignition harness or an individual lead is
to be replaced, consult the wiring diagram to be sure harness is correctly installed. Mark location of
clamps and clips to be certain the replacement is clamped at correct locations.
b. Timing Magnetos to Engine –
Although several combinations of magnetos are used on this series
engine, (see Table of Models for model application) the timing procedures, with the exception of the
method of turning the magnetos to the correct breaker position, are the same for all magnetos.
NOTE
Either the impulse coupling or retard breaker magneto (whichever is applicable) is installed
on the left side of the engine.
(1) Remove a spark plug from No. 1 cylinder and place a thumb over the spark plug hole. Rotate the
crankshaft in direction of normal rotation until the compression stroke is reached, this is indicated
by a positive pressure inside the cylinder tending to push the thumb off the spark plug hole.
Continue rotating the crankshaft until the advance timing mark on the front face of the starter ring
gear is in exact alignment with the small hole lo
position on the front face
of the starter housing. (Starter ring gear may be marked at 20° and 25°. Consult engine
specifications or nameplate for correct timing mark of your installation.)
NOTE
If the crankshaft is accidentally turned in the direction opposite normal rotation, repeat the
above procedure as accumulated backlash will make the final timing incorrect.
(2) At this point, the engine is ready for assembly of the magnetos.
(a) Bendix Magnetos –
Remove the inspection plugs from both magnetos and turn the drive shaft in
direction of normal rotation until the first painted chamfered tooth on the distributor gear is
aligned in the center of the inspection window.
(b) Slick Magnetos –
accomplished in the following manner.
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