CAUTION
Do not clean the spark plugs with a
sand blasting device. This type of
cleaning may leave abrasive material
on the plug, which can enter the cylin
der and cause damage.
6. Inspect the spark plug carefully. Look for a plug
with broken center porcelain, excessively eroded
electrodes, and excessive carbon or oil fouling. Re-
place a damaged plug. If deposits are light, the plug
may be cleaned in solvent with a wire brush. Regap
the plug as described in this section.
7. Inspect the spark plug cap and wires for cracks,
hardness or other damage. If necessary, test the
spark plug cap as described in Chapter Nine.
Gap and Installation
1. Remove the new spark plugs from the boxes. If
the terminal nut is installed, unscrew it from the end
of the plug. This adapter is not used.
2. Insert a wire feeler gauge between the center and
side electrodes of the plug (
Figure 21
). The speci-
fied gap is listed in
Table 5
. The gap is correct if
there is a slight drag as the wire is pulled through. If
there is no drag or if the gauge will not pass through,
bend the side electrode with a gaping tool (
Figure
22
) and set the gap to specification.
3. Apply a light coat of antiseize compound onto
the threads of the spark plug before installing it. Do
not use engine oil on the plug threads.
CAUTION
The cylinder head is aluminum.
Cross threading the spark plug can
easily damage the spark plug hole
threads.
4. Screw the spark plug in by hand until it seats.
Very little effort is required. If force is necessary,
the plug is cross-threaded. Unscrew it and try again.
NOTE
Do not overtighten the spark plug.
This will only distort the gasket and
destroy its sealing ability.
5. Torque the spark plugs to 20 N•m (15 ft.-lb.). If a
torque wrench is not available, turn the plug until
the gasket makes contact with the head, then tighten
the plug an additional quarter to a half turn. When
reinstalling old, regapped plugs with the old gasket,
tighten the plug an additional quarter turn.
CAUTION
Do not use a plastic hammer or any
type of tool to tap the plug cap assem
bly onto the spark plug. The assembly
will be damaged.
NOTE
Be sure to push the plug cap all the
way down to make full contact with
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