10
Spark Plug Service
To ensure proper engine operation, the spark plug must be properly gapped and free of deposits. If the
engine has been running, the muffler will be very hot. Be careful not to touch the muffler.
➢
Remove spark plug cap.
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Clean any dirt from around the spark plug base.
➢
Use a spark plug wrench to remove the spark plug.
➢
Visually inspect the spark plug. Discard it if the insulator is
cracked, chipped or fouled.
➢
Measure the plug gap with a feeler gauge. Correct as necessary by
carefully bending the side electrode.
The gap should be 0.023-0.031 inches (0.70-0.80 mm)
➢
Check that the spark plug washer is in good condition. Thread the spark plug in by hand to prevent
cross-threading.
➢
After the spark plug is seated, tighten with the spark plug wrench to compress the washer.
•
If installing a new spark plug, tighten ½ turn after the spark plug seats to compress the washer.
If reinstalling a used spark plug, tighten ⅛ - ¼ 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 could damage the engine. Never use spark
plugs which have an improper heat range. Use only recommended spark plugs or
equivalent.
Muffler and Spark Arrester (if applicable) Inspection
WARNINGS
Running engines produce heat. Engine parts, especially muffler, become extremely
hot.
Severe burns can occur on contact. Combustible debris, such as leaves, grass, brush,
etc. can catch fire.
➢
Allow muffler, engine cylinder and fins to cool before touching.
➢
Remove accumulated debris from muffler area and cylinder area.
WARNING:
Replacement parts must be the same and installed in the same position as the original
parts or fire could result.
