PERIODIC MAINTENANCE AND MINOR REPAIR
6
EAU01651
Checking the spark plug
The spark plug is an important engine
component, which should be checked
periodically, preferably by a Yamaha
dealer. Since heat and deposits will
cause any spark plug to slowly erode,
it should be removed and checked in
accordance with the periodic mainte-
nance and lubrication chart. In addition,
the condition of the spark plug can
reveal the condition of the engine.
The porcelain insulator around the
center electrode of the spark plug
should be a medium-to-light tan (the
ideal color when the scooter is ridden
normally). If the spark plug shows a
distinctly different color, the engine
could be defective. Do not attempt to
diagnose such problems yourself.
Instead, have a Yamaha dealer check
the scooter.
If the spark plug shows signs of
electrode erosion and excessive carbon
or other deposits, it should be replaced.Specified spark plug:
BR8HS (NGK)
Before installing a spark plug, the spark
plug gap should be measured with a
wire thickness gauge and, if necessary,
adjusted to specification.
Spark plug gap:
0.5 — 0.7 mm
Clean the surface of the spark plug
gasket and its mating surface, and then
wipe off any grime from the spark plug
threads.
a
ZAUM0037
a Spark plug gap
Tightening torque:
Spark plug:
20 Nm (2.0 m
•kg)
NOTE :
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.
6-6
PERIODIC MAINTENANCE AND MINOR REPAIR
6
EWA00062
•Make sure that no foreign
material enters the final trans-
mission case.
•Make sure that no oil gets on
the tire or wheel.
7. Check the final transmission case
for oil leakage. If oil is leaking,
check for the cause.
WARNING
EAU04228
Final transmission oil
The final transmission case must be
checked for oil leakage before each
ride. If any leakage is found, have a
Yamaha dealer check and repair the
scooter. In addition, the final transmis-
sion oil must be changed as follows at
the intervals specified in the periodic
maintenance and lubrication chart.
1. Start the engine, warm it up by
riding the scooter for several mi-
nutes, and then stop the engine.2. Place the scooter on the
centerstand.
3. Place an oil pan under the final
transmission case to collect the
used oil.
4. Remove the oil filler cap and drain
bolt to drain the oil from the final
transmission case.
5. Install the final transmission oil
drain bolt, and then tighten it to
the specified torque.
Tightening torque:
Final transmission oil drain bolt:
18 Nm (1.8 m
•kgf)
6. Add the specified amount of the
recommended final transmission
oil, and then install and tighten the
oil filler cap.
Recommended final transmission
oil:
See page 8-1.
Oil quantity:
0.13 L
12ZAUM0273
1. Final transmission oil drain bolt
2. Oil filler cap
6-7
SPECIFICATIONS
8
EAU04513
Conversion table
All specification data in this manual are listed in SI and
METRIC UNITS.
Use this table to convert METRIC unit values to IMPERIAL
unit values.
Example:
METRIC VALUE CONVERSION
FACTORIMPERIAL VALUE
2 mm 0.03937 = 0.08 in
Conversion table
METRIC SYSTEM TO IMPERIAL SYSTEM
Metric unit Conversion factor Imperial unit
Torquem•kgf
m•kgf
cm•kgf
cm•kgf
7.233 86.794 0.0723 0.8679ft•lbf
in•lbf
ft•lbf
in•lbf
Weightkg
g
2.205 0.03527lb
oz
Speed km/h
0.6214 mi/h
Distancekm
m
m
cm
mm
0.6214 3.281 1.094 0.3937 0.03937mi
ft
yd
in
in
Volume,
Capacitycc (cm3)
cc (cm3)
L (liter)
L (liter) 0.03527 0.06102 0.8799 0.2199oz (IMP liq.)
cu•in
qt (IMP liq.)
gal (IMP liq.)
Miscellaneouskg/mm
kgf/cm
2
C
55.997 14.2234 1.8 + 32 lb/in
psi (lbf/in
2)
F
8-4
