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Spark Plug Inspection
The spark plug is important engine components, which
should be checked periodically.
1. Remove the spark plug cap and the spark plug.
1 Spark plug cap
2 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.
Standard spark plug:
BPR4ES (NGK)
Spark plug gap:
0.7–0.8 mm (0.028–0.031 in)
a Spark plug gap
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.
Spark plug tightening torque:
20 N·m (2.0 kgf·m, 15 lb·ft)
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.
Carburetor Adjustment
The carburetor is a vital part of the engine. Adjusting
should be left to a Yamaha dealer with the professional
knowledge, specialized data, and equipment to do so
properly.
7P5-F8199-14.indd 40 2021/06/23 11:22:18
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