Spark Plug Installation - Lycoming TEO-540-C1A Maintenance Manual

TEO-540-C1A Engine Maintenance Manual
TEO-540-C1A Engine Maintenance Manual

11. Spark Plug Installation

NOTICE: Complete the "Spark Plug Gap Setting" procedure and as necessary the "Spark Plug
Gap Rotation" procedure in this chapter before spark plug installation.
A. If not already done, apply C5-A Copper-Based Anti-Seize (Figure 6) or engine oil to the
threads of each spark plug (starting two full threads from the electrode.)
CAUTION
CAUTION
B. Install a new spark plug gasket with the spark plug. A new gasket must be installed whether
the spark plug is new or is acceptable and being reused.
C. Install a spark plug in the cylinder top and bottom (Figure 2) according to the manufacturer's
recommendations.
D. Torque the spark plug to 420 in.-lb. (or 35 ft.-lb.) (47.5 Nm) or per the spark plug
manufacturer's instructions.
E. Connect the spark plug to the applicable ignition lead per the "Ignition Lead Installation"
procedure in this chapter.
F. Torque the spark plug lead nut to 110 to 120 in.-lb. (12 to 13.6 Nm) or per the spark plug
manufacturer's instructions.
12. Ignition Lead Installation
WARNING MAKE SURE THE BATTERY HAS BEEN DISCONNECTED FROM THE
ENGINE.
NOTICE: If a new ignition lead (Figure 7) is to be installed, refer to the TEO-540-C1A Illustrated
Parts Catalog to identify the correct part number of the replacement ignition lead.
Examine the ignition leads as per the procedure "Ignition Lead Inspection" in this chapter.
A.
NOTICE: The coil box lid is marked with a letter and number for each ignition lead
identifying a spark plug on each respective cylinder. An ignition lead position
marked "T1" identifies the top spark plug on cylinder #1 to which that ignition lead
is to be connected. An ignition lead position marked "B4" identifies the bottom
spark plug on cylinder #4 to which that ignition lead is to be connected.
Apply C5A Copper Based Anti-Seize or
B.
equivalent to the threads (Figure 7) on the
coil box end of the ignition lead.
© 2018 Avco Corporation. All Rights Reserved
November 2018
FAILURE TO INSTALL A NEW SPARK PLUG GASKET ANY TIME A
SPARK PLUG IS INSTALLED CAN RESULT IN INCOMPLETE
SEALING OF THE COMBUSTION CHAMBER, LOSS OF SPARK PLUG
HEAT TRANSFER, SPARK PLUG OVERHEATING, POSSIBLE
REIGNITION/DETONATION, AND INTERNAL ENGINE DAMAGE.
NEVER INSTALL A SPARK PLUG THAT HAS BEEN DROPPED ON
THE FLOOR.
Figure 7
Ignition Lead
74-20
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