PERIODIC MAINTENANCE AND MINOR REPAIR
6-6
6
EAU19620
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 ac-
cordance with the periodic mainte-
nance and lubrication chart. In addition,
the condition of the spark plug can re-
veal the condition of the engine.
The porcelain insulator around the cen-
ter electrode of the spark plug should
be a medium-to-light tan (the ideal color
when the vehicle is ridden normally). If
the spark plug shows a distinctly differ-
ent color, the engine could be defec-
tive. Do not attempt to diagnose such
problems yourself. Instead, have a
Yamaha dealer check the vehicle.
If the spark plug shows signs of elec-
trode erosion and excessive carbon or
other deposits, it should be replaced.Before installing a spark plug, the spark
plug gap should be measured with a
wire thickness gauge and, if necessary,
adjusted to specification.
Clean the surface of the spark plug
gasket and its mating surface, and then
wipe off any grime from the spark plug
threads.
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 speci-fied torque as soon as possible.
Specified spark plug:
NGK/BR8HS
1. Spark plug gap
Spark plug gap:
0.6–0.7 mm (0.024–0.028 in)
Tightening torque:
Spark plug:
20 Nm (2.0 m·kgf, 14.5 ft·lbf)
1
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-7
6
EAU20060
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 min-
utes, and then stop the engine.
2. Place the scooter on the center-
stand.
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.
6. Add the specified amount of the
recommended final transmission
oil, and then install and tighten the
oil filler cap.
WARNING
EWA11310
Make sure that no foreign mate-
rial enters the final transmission
case.
Make sure that no oil gets on thetire or wheel.
7. Check the final transmission case
for oil leakage. If oil is leaking,
check for the cause.
1. Final transmission oil drain bolt
2. Final transmission oil filler capTightening torque:
Final transmission oil drain bolt:
18 Nm (1.8 m·kgf, 13.0 ft·lbf)
Recommended final transmission
oil:
See page 8-1.
Oil quantity:
0.11 L (0.12 US qt) (0.10 Imp.qt)
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