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PERIODIC MAINTENANCE AND MINOR REPAIR
EAUT1170
Checking the spark plug
The spark plug is an important engine
component, which is easy to check.
Since heat and deposits will cause any
spark plug to slowly erode, the spark
plug should be removed and checked in
accordance with the periodic mainte-
nance and lubrication chart. In addition,
the condition of the spark plug can re-
veal the condition of the engine.
To remove the spark plug
1. Remove panel C. (See page 6-6.)
2. Remove the spark plug cap.
3. Remove the spark plug as shown,
with the spark plug wrench included
in the owner’s tool kit.
ZAUM00**
1
1. Spark plug wrench
To check the spark plug
1. Check that the porcelain insulator
around the center electrode of the
spark plug is a medium-to-light tan
(the ideal color when the vehicle is
ridden normally).
NOTE:
If the spark plug shows a distinctly dif-
ferent color, the engine could be defec-
tive. Do not attempt to diagnose such
problems yourself. Instead, have a
Yamaha dealer check the vehicle.
2. Check the spark plug for electrode
erosion and excessive carbon or
other deposits, and replace it if nec-
essary.
Specified spark plug:
CR7E (NGK)
To install the spark plug
1. Measure the spark plug gap with a
wire thickness gauge and, if nec-
essary, adjust the gap to specifi-
cation.
ZAUM00**
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2(
×
4)
1. Panel B
2. Screw
To install the panel
Place the panel in the original position,
and then install the screws.
5ML-F8199-E0ch6re.pmd
2003/12/12, 16:04
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Summary of Contents for CYGNUS 125
Page 1: ...5ML F8199 E0 OWNER S MANUAL NXC125 ...
Page 2: ...2003 12 12 16 02 ...
Page 12: ...1 5 2003 12 12 16 02 ...
Page 13: ...1 6 1 2 3 4 5 6 7 8 9 Q Q Q Q Q SAFETY INFORMATION 2003 12 12 16 02 ...
Page 14: ...2 1 EAU10410 EAU10400 2 3 4 5 6 7 8 2003 12 12 16 02 ...
Page 15: ...2 2 1 2 3 4 5 6 7 8 9 DESCRIPTION EAU10420 1 2 3 5 2003 12 12 16 02 ...
Page 16: ...2 3 EAU10430 2 3 4 5 6 7 8 2003 12 12 16 02 ...
Page 27: ...3 11 1 2 3 4 5 6 7 8 9 INSTRUMENT AND CONTROL FUNCTIONS 2003 12 12 16 03 ...
Page 34: ...5 4 RIDING POINTS 2003 12 12 16 03 ...
Page 36: ...6 2 MINOR REPAIR 2003 12 12 16 04 ...
Page 63: ...6 29 1 2 3 4 5 6 7 8 9 PERIODIC MAINTENANCE AND MINOR REPAIR 2003 12 12 16 04 ...
Page 71: ...8 3 1 2 3 4 5 6 7 8 9 SPECIFICATIONS 2003 12 12 16 04 ...
Page 73: ...9 2 1 2 3 4 5 6 7 8 9 CONSUMER INFORMATION 2003 12 12 16 05 ...
Page 75: ...2003 12 12 14 37 ...
Page 76: ...PRINTED IN TAIWAN E 2003 12 0 3 1 YAMAHA MOTOR TAIWAN CO LTD ...