The standard spark plug is shown in the table. The spark plugs should be replaced in accordance with the Periodic Maintenance Chart.
Spark plug removal should be done only by a competent mechanic following the instructions in the Service Manual.
Spark Plug

A. Plug Gap
Coolant Filling
Evaporative Emission Control System (California
model only)Headlight Aiming Adjustment
NOTE
Do not turn the bolts [A] because the reflector in the
headlight comes off.
(In the photo, the headlight unit has been removed for
clarity.)
NOTE
The left adjuster [A] and right adjuster [B] can move the
direction of the headlight beam to up, down, left and
right by turning each a ...
Cylinder (Upper Crankcase) Wear Inspection
Split the crankcase (see Crankcase Splitting).
Remove the pistons (see Piston Removal).
Assemble the cylinder (upper crankcase) [A], the cylinder
head [B] and the cylinder head gasket [C].
Tighten the cylinder head bolts (see Cylinder Head Installation
in the Engine Top End chapter).
...
Air Switching Valve Installation
Install the air switching valve [A] with hose [B] as shown
in the figure.
Front [C]
Left Side View [D]
White Paint [E]
Air Switching Valve Operation Test
Refer to the Air Suction System Damage Inspection in the
Periodic Maintenance chapter.
Air Switching Valve Unit Test ...