Spark Plug Inspection - Yamaha MZ250 Manuel D'utilisation

a

Spark plug inspection

The spark plug is an important engine component,
which should be checked periodically.
1. Remove the spark plug cap and the spark plug.
2. Check for discoloration and remove the carbon.
The porcelain insulator around the center elec-
trode of spark plug should be a medium-to-light
tan color.
3. Check the spark plug type and gap.
a Spark plug gap
Standard spark plug:
BPR4ES (NGK)
Spark plug gap:
0.7–0.8 mm (0.028–0.031 in)
TIP
The spark plug gap should be measured with a wire
thickness gauge and, if necessary, adjusted to specifi-
cation.
4. Install the spark plug and then tighten it.
Spark plug tightening torque:
20 Nm (2.0 m·kgf, 14 ft·lbf)
TIP
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 specified torque as soon as
possible.
5. Install the spark plug cap.
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