Checking The Spark Plugs - Yamaha MT-09 Owner's Manual

Periodic Maintenance And Adjustment
Panel B
To remove the panel
1. Remove the bolts and washers.
7
1 2
1 2
1. Bolt
2. Washer
2. Pull the panel outward as shown.
1. Panel B
To install the panel
Place the panel in the original
position, and then install the washers
and bolts.
7-10

Checking the spark plugs

The spark plugs are important engine
components,
checked periodically, preferably by a
1
Yamaha dealer. Since heat and
deposits will cause any spark plug to
slowly erode, they should be removed
and checked in accordance with the
periodic maintenance and lubrication
chart. In addition, the condition of the
spark plugs can reveal the condition
of the engine.
The porcelain insulator around the
center electrode of each spark plug
should be a medium-to-light tan (the
ideal color when the vehicle is ridden
normally), and all spark plugs installed
in the engine should have the same
color. If any spark plug shows a
distinctly different color, the engine
could be operating improperly. Do not
attempt to diagnose such problems
yourself. Instead, have a Yamaha
dealer check the vehicle. If a spark
plug shows signs of electrode erosion
and excessive
deposits, it should be replaced.
Specified spark plug:
NGK/CPR9EA9
which should be
carbon or other