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760-001a
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 Nm (2.0 m·kgf, 14 ft·lbf)
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.
Summary of Contents for EF4000DFW
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Page 48: ...PRINTED IN CHINA 2014 05 1 E ...
Page 94: ...IMPRIMÉ EN CHINE 2014 05 1 F ...
Page 140: ...GEDRUCKT IN CHINA 2014 05 1 G ...
Page 186: ...STAMPATO IN CINA 2014 05 1 H ...
Page 188: ......
Page 234: ...IMPRESSO NA CHINA 2014 05 1 P ...
Page 280: ...IMPRESO EN CHINA 2014 05 1 S ...
Page 326: ...GEDRUKT IN CHINA 2014 05 1 D ...
Page 372: ...DICETAK DI CINA 2014 05 1 B ...