Checking The Spark Plugs - Yamaha VMX EAU10041 Owner's Manual

Panel B
To remove the panel
Remove the screws, and then take the
panel off.
1. Screw
To install the panel
Place the panel in the original position,
and then install the screws.
PERIODIC MAINTENANCE AND MINOR REPAIR
EAU19210

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.
1. Spark plug cap
2. Remove the spark plug as shown,
with the spark plug wrench includ-
ed in the owner's tool kit.
EAU19543
1. Spark plug wrench
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 vehicle.
6-9
around the center electrode on
each spark plug is a medium-to-
light tan (the ideal color when the
vehicle is ridden normally).
in the engine have the same color.
6