Checking The Spark Plug - Yamaha 2011 WR250X Owner's Manual

2. Lift the bottom of the panel slightly,
and then slide the panel forward.
To install the panel
Place the panel in the original position,
and then install the bolts.
Panel D
To remove the panel
1. Remove the seat. (See 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
To install the panel
1. Place the panel in the original posi-
tion, and then install the washer
and bolt.
2. Install the seat.
7-9

Checking the spark plug

The spark plug is an important engine
component, which should be checked
3
periodically, preferably by a Yamaha
dealer. Since heat and deposits will
cause any spark plug to slowly erode, it
2
should be removed and checked in ac-
1
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
EAU48340
7