Checking The Spark Plug - Yamaha WR25R 2008 Owner's Manual

Panel D
To remove the panel
1. Remove the seat.
page 4-13.)
2. Remove the bolt and washer, and
then remove the panel as shown.
PERIODIC MAINTENANCE AND ADJUSTMENT
1. Bolt
2. Washer
3. Panel D
(See
To install the panel
1. Place the panel in the original po-
sition, and then install the washer
and bolt.
2. Install the seat.
7-10

Checking the spark plug

The spark plug is an important engine
component, which should be checked
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periodically, preferably by a Yamaha
dealer. Since heat and deposits will
cause any spark plug to slowly erode, it
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should be removed and checked in ac-
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cordance with the periodic mainte-
nance and lubrication chart. In addition,
the condition of the spark plug can re-
veal the condition of the engine.
The porcelain insulator around the cen-
ter electrode of the spark plug should
be a medium-to-light tan (the ideal color
when the vehicle is ridden normally). If
the spark plug shows a distinctly differ-
ent color, the engine could be operating
improperly. Do not attempt to diagnose
such problems yourself. Instead, have
a Yamaha dealer check the vehicle.
If the spark plug shows signs of elec-
trode erosion and excessive carbon or
other deposits, it should be replaced.
Specified spark plug:
NGK/CR9EK
Before installing a spark plug, the spark
EAU19622
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