Checking The Spark Plugs - Yamaha YZF-R1R Owner's Manual

PERIODIC MAINTENANCE AND MINOR REPAIR
1. Quick fastener screw (× 2)
2. Screw
Panels A and B
To remove one of the panels
Loosen the quick fastener screws 1/4
6
turn counterclockwise, remove the
screw, and then take the panel off.
To install the panel
Place the panel in the original position,
tighten the quick fastener screws, and
then install the screw.

Checking the spark plugs

The spark plugs are important engine
components, which should be checked
periodically, preferably by a 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 mainte-
nance and lubrication chart. In addition,
the condition of the spark plugs can re-
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veal the condition of the engine.
6-11
The porcelain insulator around the cen-
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ter electrode of each spark plug should
be a medium-to-light tan (the ideal col-
or when the motorcycle is ridden nor-
mally), and all spark plugs installed in
the engine should have the same color.
If any 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 motorcycle.
If a spark plug shows signs of electrode
erosion and excessive carbon or other
deposits, it should be replaced.
Specified spark plug:
CR9EIA 9 (NGK) or
IU27D (DENSO)