Checking The Spark Plugs - Yamaha Thundercat YZF600R Owner's Manual

1. Spark plug cap (× 2 on each side)

Checking the spark plugs

The spark plugs are important engine
components, which are easy to check.
Since heat and deposits will cause any
spark plug to slowly erode, the spark
plugs 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-
veal the condition of the engine.
To remove a spark plug
1. Remove the spark plug cap.
PERIODIC MAINTENANCE AND MINOR REPAIR
1. Spark plug wrench
2. Remove the spark plug as shown,
EAU03329
with the spark plug wrench includ-
ed in the owner's tool kit.
To check the spark plugs
1. Check that the porcelain insulator
2. Check that all spark plugs installed
NOTE:
_
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.
_
6-8
around the center electrode on
each spark plug is a medi-
um-to-light tan (the ideal color
when the motorcycle is ridden nor-
mally).
in the engine have the same color.
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