TM 3-4230-218-12&P
b.
Cleaning Spark Plugs.
Same procedure for
ner.
(1) Allow
NOTE
cleaning spark plugs will be followed on engine and bur-
engine to cool down prior to performing this procedure.
DO NOT PULL ON SPARK PLUG
TOR INSIDE.
(2) Disconnect spark
spark plug.
CAUTION
CABLE AS THIS COULD BREAK THE CONDUC-
plug cable by pulling spark plug cap off
CAUTION
BE SURE THAT NO DIRT FALLS INTO THE SPARK PLUG HOLE.
(3)
(4)
(5)
(6)
Use spark plug wrench to unscrew spark plug from engine
cylinder head or burner weldment.
Make sure metal sealing
washer is attached to plug.
Use wire brush to clean carbon deposits from electrode area of
the plug.
Dip threaded portion of plug into solvent to wash
away carbon residue.
Allow plug to air dry.
Inspect plug for cracked insulator. Use feeler gage to check
gap between the electrodes. This gap should be .030 in. for
engine plug and .070 in. for burner plug.
Obtaining a gap of
.070 in. will require combining several blades (i. e. .030 in. +
.025 in. + .015 in. ) of gap gage.
Use gap gage to change plug
gap if required.
Be sure metal gasket is in place on plug prior to installation.
Screw plug in as far as possible by hand. Tighten firmly with
spark plug wrench (approximately 1/8 turn beyond handtight).
Push spark plug cap squarely over plug end.
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