Lycoming TIO-540-A1A, Operator'S Manual

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SECTION 5 LYCOMING OPERATOR’S MANUAL
MAINTENANCE PROCEDURES TIO-540 SERIES – ANGLE VALVE CYLINDER HEADS
WARNING
DO NOT ATTACH HARNESS SPARK PLUG ENDS TO THE SPARK PLUGS UNTIL ALL
MAGNETO-TO-ENGINE
TIMING PROCEDURES AND MAGNETO-TO-SWITCH
CONNECTIONS ARE ENTIRELY COMPLETED.
(7) To remove engine-to-magneto drive gear train backlash by turning engine magneto drive as far as
possible in direction opposite to normal rotation and then return in the direction of normal
rotation to timing mark on starter support.
(8) Remove the timing window plug from the most convenient side of the magneto housing and the
plug from the rotor viewing location in the center of the housing.
(9) Turn the rotating magnet drive shaft in the normal direction of magneto rotation until the painted
tooth of the large distributor gear is centered in the timing hole.
(10) Observe that at this time the built in pointer just ahead of the rotor viewing window aligns with
the R or L mark on the rotor depending on whether the magneto is of right or left hand rotation as
specified on the magneto nameplate.
(11) Hold the magneto in its No. 1 firing position (tooth in window center and pointer over R or L
mark on rotor) and install magneto to the engine and loosely clamp in position.
(12) Attach red lead from the timing light to left switch adapter lead, green lead of timing light to right
switch adapter lead and the black lead of the light to magneto housing.
(13) Turn the entire magneto in direction of rotor rotation until the red timing light comes on.
(14) Rotate the magneto in the opposite direction until the red light just goes off indicating left main
breaker has opened. Then evenly tighten the magneto mounting clamps.
(15) Back the engine up approximately 10° and then carefully “bump” the engi ne forward at the same
time observing the timing lights.
(16) At the No. 1 firing position of the engine, the red light should go off indicating left main breaker
opening. The right main breaker, monitored by the green light, must open within ± 2 engine
degrees of the No. 1 firing position.
(17) Repeat steps (13) thru (15) until the condition described in step (16) is obtained.
(18) Complete tightening of the magneto securing clamps by torquing to 150 in.-lbs.
(19) Recheck timing once more and if satisfactory disconnect timing light. Remove adapter leads.
(20) Reinstall plugs in timing inspection holes and torque to 12-15 in.-lbs.
NOTE
Some timing lights operate in the reverse manner as described. The light comes on when the
breaker points open. Check your timing light instructions.
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