Honda WX15 Manual De Explicaciones página 33

5.Check that the sealing washer is in good condition, and thread the
spark plug in by hand to prevent cross-threading.
6.After the spark plug is seated, tighten with a spark plug wrench to
compress the washer.
NOTE:
If installing a new spark plug, tighten 1/2 turn after the spark plug
seats to compress the washer. If reinstalling a used spark plug, tighten
1/8–1/4 turn after the spark plug seats to compress the washer.
CAUTION:
• The spark plug must be securely tightened. An improperly tightened
spark plug can become very hot and may cause engine damage.
• Use only the recommended spark plug or equivalent. Spark plugs
which have an improper heat range may cause engine damage.
7.Attach the spark plug cap securely.
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