Yamaha YW50Z Owner's Manual page 46

PERIODIC MAINTENANCE AND ADJUSTMENT
1
2
3
ZAUM00**
1. Spark plug cap
4
To check the spark plug
1. Check that the porcelain insulator
5
around the center electrode of the
spark plug is a medium-to-light tan
(the ideal color when the vehicle is
6
ridden normally).
7
TIP
If the spark plug shows a distinctly dif-
8
ferent color, the engine could be operat-
ing improperly. Do not attempt to diag-
9
nose such problems yourself. Instead,
have a Yamaha dealer check the vehicle.
2. Check the spark plug for electrode
erosion and excessive carbon or
other deposits, and replace it if nec-
essary.
1
Specified spark plug:
BPR7HS (NGK)
To install the spark plug
1. Measure the spark plug gap with a
wire thickness gauge and, if nec-
essary, adjust the gap to specifi-
cation.
1
ZAUM00**
1. Spark plug gap
2. Clean the surface of the spark plug
3. Install the spark plug with the spark
TIP
If a torque wrench is not available when
installing a spark plug, a good estimate
of the correct torque is 1/4 ~ 1/2 turn
past finger tight. However, the spark plug
should be tightened to the specified
torque as soon as possible.
4. Install the spark plug cap.
5. Install the panel.
6-46 6-9
Spark plug gap:
0.6 ~ 0.7 mm (0.024 ~ 0.028 in)
gasket and its mating surface, and
then wipe off any grime from the
spark plug threads.
plug wrench, and then tighten it to
the specified torque.
Tightening torque:
Spark plug:
20 Nm (2.0 m • kgf, 14.4ft • lbf)
EAU1722A