Yamakoyo SH2900DX, Owner'S Manual

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If the engine has been running, the muffler will be very hot. Be careful not to touch
the muffler.
1. Remove the spark plug cap.
2. Clean any dirt from around the spark plug base.
3. Use the wrench supplied in the tool kit to remove the spark plug.
5. Visually inspect the spark plug. Discard it if the insulator is cracked or chipped.
Clean the spark plug with a wire brush if it is to be reused.
6. Measure the plug gap with a feeler gauge. Correct as necessary by carefully
bending the side electrode.
The gap should be: 0.70-0.80 mm (0.028-0.031 in)
20
MAINTENANCE
18
0.70-0.80 mm(0.028-0.031 in )
PLUG WRENCH
PLUG CAP
7. Check that the spark plug washer is in good condition, and thread the spark plug
in by hand to prevent cross-threading.
8. After the spark plug is seated, tighten with a spark plug wrench to compress the
washer.
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.
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 the
recommended spark plugs or equivalent.
NOTICE