Checking The Spark Plugs - Yamaha TMAX XP500 Owner's Manual

PERIODIC MAINTENANCE AND ADJUSTMENT
1
1
2
3
1. Screw
4
2. Panel D
5
To install the panel
Place the panel in the original position,
6
and then install the screws.
7
8
9
2

Checking the spark plugs

1
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-
veal the condition of the engine.
The porcelain insulator around the cen-
ter 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 en-
gine should have the same color. If any
spark plug shows a distinctly different
color, the engine could be operating im-
properly. 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 carbon or other
deposits, it should be replaced.
Specified spark plug:
NGK/CR7E
EAU19642 Before installing a spark plug, the spark
plug gap should be measured with a
wire thickness gauge and, if necessary,
adjusted to specification.
1. Spark plug gap
Clean the surface of the spark plug
gasket and its mating surface, and then
wipe off any grime from the spark plug
threads.
TIP
If a torque wrench is not available when
6-10
Spark plug gap:
0.7–0.8 mm (0.028–0.031 in)
Tightening torque:
Spark plug:
13 Nm (1.3 m·kgf, 9.4 ft·lbf)