Lycoming TIO-540-A1A, Operator'S Manual

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LYCOMING OPERATOR’S MANUAL SECTION 5
TIO-540 SERIES – ANGLE VALVE CYLINDER HEADS 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 Magneto to 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 alignment with the sm
all hole located at the two o’cloc k position on the front face of the
starter housing. (Ring gear may be marked at 20° and 25°. Consult specifications for correct
timing mark for your installation.) At this point, the engine is ready for assembly of the magneto.
(2)
Single Magneto
– Remove the inspection plugs from both magnetos and turn the drive shaft in
direction of normal rotation until (-1200 series) the applicable timing mark on the distributor gear
is approximately aligned with the mark on the distributor block. See Figure 5-2. Being sure the
gear does not move from this position, install gaskets and magnetos to the engine. Note that an
adapter is used with a
ll magnetos. Secure with (clamps on – 1200 series) washers and nuts; tighten
only finger tight.
(3) Using a battery powered timing light, attach the positive lead to a suitable terminal connected to
the switch terminal of the magneto and the negative lead to any unpainted portion of the engine.
Rotate the magneto in its mounting flange to a point where the light comes on, then slowly turn it
in the opposite direction until the light goes out. Bring the magneto back slowly until the light just
comes on. Repeat this with the second magneto.
(4) Back off the crankshaft a few degrees, the timing lights should go out. Bring the crankshaft
slowly back in direction of normal rotation until the timing mark and the hole in the starter
housing are in alignment. At this point, both lights should go on simultaneously. Tighten nuts to
specified torque.
(5)
Dual Magnetos
– Place the engine in the No. 1 advance firing position as directed in paragraph 1,
b, (1).
(6) Install the magneto-to-engine gasket on the magneto flange.
5-1