Yamaha TW200ET Owner's Manual page 42

PERIODIC MAINTENANCE AND MINOR REPAIR
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1. Spark plug wrench
4 To check the spark plug
1. Check that the porcelain insulator
around the center electrode of the
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spark plug is a medium-to-light tan
(the ideal color when the vehicle is
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ridden normally).
NOTE:
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If the spark plug shows a distinctly dif-
ferent color, the engine could be defec-
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tive. Do not attempt to diagnose such
problems yourself. Instead, have a
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Yamaha dealer check the vehicle.
2. Check the spark plug for electrode
erosion and excessive carbon or
other deposits, and replace it if
necessary.
Specified spark plug:
NGK/DR8EA
DENSO/X24ESR-U
To install the spark plug
1. Measure the spark plug gap with a
wire thickness gauge and, if nec-
essary, adjust the gap to specifica-
tion.
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1. Spark plug gap
Spark plug gap:
0.6–0.7 mm (0.024–0.028 in)
2. Clean the surface of the spark plug
gasket and its mating surface, and
then wipe off any grime from the
spark plug threads.
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3. Install the spark plug with the
spark plug wrench, and then tight-
en it to the specified torque.
Tightening torque:
Spark plug:
17.5 Nm (1.75 m·kgf, 12.5 ft·lbf)
NOTE:
If a torque wrench is not available when
installing a spark plug, a good estimate
of the correct torque is 1/4–1/2 turn
past finger tight. However, the spark
plug should be tightened to the speci-
fied torque as soon as possible.
4. Install the spark plug cap.