How to gap new spark plugs
1 of 2
Photo 1: Check the gap with a gap gauge
Find the “gapping wire”
that matches the
recommended gap. Then
slide it between the center
and side electrodes. When
the gap is correct, the
gauge should drag slightly
going in and out. If the gap
is too large or the wire
won't fit, adjust the side
electrode.
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Photo 2: Bend the side electrode
Hook the side electrode
with the gauge's bending
arm. Then pivot the arm
in or out in small
increments to open or
close the gap. Recheck
with the gauge until you
get a snug fit.
Spark plugs don't come
gapped for your particular
engine. For the best performance,
you must gap the
plug to the engine manufacturer's
specs. If you're
buying a plug for a small
engine, ask the parts store
to look up the gap size info
for you. If the plugs are for
your vehicle, find the info in
the owner's manual. Then
adjust the gap as shown.
