Checking The Spark Plug - Yamaha DT125R Owner's Manual

PERIODIC MAINTENANCE AND MINOR REPAIR
1
1. Spark plug cap

Checking the spark plug

The spark plug is an important
engine component, which is easy to
6
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 maintenance and lubrication
chart. In addition, the condition of the
spark plug can reveal the condition of
the engine.
To remove the spark plug
1. Remove the spark plug cap.
1. Spark plug wrench
EAU01833
2. Remove the
shown, with the spark plug
wrench included in the owner's
tool kit.
To check the spark plug
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1. Check that the porcelain insula-
NOTE:
If the spark plug shows a distinctly
different color, the engine could be
defective. Do not attempt to diagnose
spark plug as
such
have a Yamaha dealer check the
motorcycle.
2. Check the spark plug for elec-
6-9
tor around the center electrode
of the spark plug is a medium-to-
light tan (the ideal color when the
motorcycle is ridden normally).
problems yourself.
trode erosion and excessive car-
bon or other deposits,
replace it if necessary.
Specified spark plug:
BR9ES (NGK)
BR8ES (NGK) (CH, A only)
Instead,
and