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PERIODIC MAINTENANCE AND MINOR REPAIR
6-8
6
To check the spark plug
1. Check that the porcelain insulator around the center electrode of the
spark plug is a medium-to-light tan
(the ideal color when the vehicle is
ridden normally).
NOTE:If the spark plug shows a distinctly dif-
ferent color, the engine could be defec-
tive. Do not attempt to diagnose such
problems yourself. Instead, have aYamaha dealer check the vehicle.
2. Check the spark plug for electrode erosion and excessive carbon or
other deposits, and replace it if
necessary.
To install the spark plug 1. Measure the spark plug gap with a wire thickness gauge and, if nec-
essary, adjust the gap to specifica-
tion. 2. Clean the surface of the spark plug
gasket and its mating surface, and
then wipe off any grime from the
spark plug threads.
3. Install the spark plug with the spark plug wrench, and then tight-
en it to the specified torque.
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.
4. Install the spark plug cap.
5. Place the resonator in the original position, and then tighten the bolt
to the specified torque.
6. Install the cowling.
Specified spark plug: NGK/CPR8EA-9/DENSO U24EPR-9
1. Spark plug gap
Spark plug gap: 0.8 –0.9 mm (0.031 –0.035 in)
Tightening torque: Spark plug:12.5 Nm (1.25 m ·kgf, 9.0 ft ·lbf)
Tightening torque:
Resonator bolt: 10 Nm (1.0 m ·kgf, 7.2 ft ·lbf)
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-9
6
EAU37570
Engine oil and oil filter
element The engine oil level should be checked
before each ride. In addition, the oil
must be changed and the oil filter ele-
ment replaced at the intervals specified
in the periodic maintenance and lubri-
cation chart.
To check the engine oil level
1. Place the vehicle on the center-
stand.NOTE:
Make sure that the vehicle is positioned
straight up when checking the oil level.
A slight tilt to the side can result in afalse reading.
2. Start the engine, warm it up for
several minutes, and then turn it
off.
3. Wait a few minutes until the oil set-
tles, remove the oil filler cap, wipe
the dipstick clean, insert it back
into the oil filler hole (without
screwing it in), and then remove it
again to check the oil level.
NOTE:
The engine oil should be between theminimum and maximum level marks.4. If the engine oil is at or below the
minimum level mark, add sufficient
oil of the recommended type to
raise it to the correct level.
5. Insert the dipstick into the oil filler
hole, and then tighten the oil filler
cap.
To change the engine oil (with or
without oil filter element replace-
ment)
1. Start the engine, warm it up for
several minutes, and then turn it
off.
2. Place an oil pan under the engine
to collect the used oil.
3. Remove the engine oil filler cap
and drain bolt along with the O-
ring, compression spring, and en-
gine oil strainer, to drain the oil
from the crankcase.1. Engine oil filler cap
1. Dipstick
2. Maximum level mark
3. Minimum level mark
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-10
6
CAUTION:
ECA11000
When removing the engine oil drain
bolt, the O-ring, compression
spring, and oil strainer will fall out.Take care not to lose these parts.NOTE:Check the O-ring for damage and re-place it if necessary.
4. Clean the engine oil strainer with
solvent.
NOTE:Skip steps 5–7 if the oil filter element isnot being replaced.
5. Remove the oil filter element cover
by removing the bolts.
6. Remove and replace the oil filter
element and O-ring.7. Install the oil filter element cover by
installing the bolts, then tightening
them to the specified torque.
NOTE:Make sure that the O-ring is properlyseated.
8. Install the engine oil strainer, com-
pression spring, O-ring and engine
oil drain bolt, and then tighten the
drain bolt to the specified torque.
1. Engine oil drain bolt
2. O-ring
3. Compression spring
4. Strainer
5. Oil pan
1. Bolt
2. Oil filter element cover
1. Oil filter element
2. O-ring
Tightening torque:
Oil filter element cover bolt:
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-11
6
CAUTION:
ECA10420
Before installing the engine oil drain
bolt, do not forget to install the O-
ring, compression spring, and oilstrainer in position.
9. Add the specified amount of the
recommended engine oil, and then
install and tighten the oil filler cap.CAUTION:
ECA11620
In order to prevent clutch slip-
page (since the engine oil also
lubricates the clutch), do not
mix any chemical additives. Donot use oils with a diesel speci-
fication of “CD” or oils of a high-
er quality than specified. In
addition, do not use oils labeled
“ENERGY CONSERVING II” or
higher.
Make sure that no foreign mate-rial enters the crankcase.
10. Start the engine, and then let it idle
for several minutes while checking
it for oil leakage. If oil is leaking, im-
mediately turn the engine off and
check for the cause.
11. Turn the engine off, and then
check the oil level and correct it if
necessary.
EAU20070
Coolant The coolant level should be checked
before each ride. In addition, the cool-
ant must be changed at the intervals
specified in the periodic maintenance
and lubrication chart.
EAU37510
To check the coolant level
The coolant level should be checked as
follows before each ride. In addition,
the coolant must be changed at the in-
tervals specified in the periodic mainte-
nance and lubrication chart.
1. Place the vehicle on the center-
stand.NOTE:
The coolant level must be checked
on a cold engine since the level
varies with engine temperature.
Make sure that the vehicle is posi-
tioned straight up when checking
the coolant level. A slight tilt to theside can result in a false reading.
2. Check the coolant level in the cool-
ant reservoir.
Tightening torque:
Engine oil drain bolt:
32 Nm (3.2 m·kgf, 23 ft·lbf)
Recommended engine oil:
See page 8-1.
Oil quantity:
With oil filter element replacement:
0.90 L (0.95 US qt) (0.79 Imp.qt)
Without oil filter element replace-
ment:
0.80 L (0.85 US qt) (0.70 Imp.qt)
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-12
6
NOTE:The coolant should be between theminimum and maximum level marks.3. If the coolant is at or below the minimum level mark, remove cowl-
ing A. (See page 6-5.)
4. Loosen the coolant reservoir cap retainer bolt, and then lift the re-
tainer upward.
5. Remove the coolant reservoir cap, and then add coolant to the maxi-
mum level mark.
CAUTION:
ECA10470
use only YAMAHA GENUINE
COLANT. Using coolan other than
recommended, could cause damage
to oil seal and o-rings, as whell
as to the cooling system. If water has been used instead
of coolant, replace it with cool-
ant as soon as possible, other-
wise the engine may not be sufficiently cooled and the cool-
ing system will not be protected
against frost and corrosion.
If water has been added to the
coolant, have a Yamaha dealer
check the antifreeze content of
the coolant as soon as possible,
otherwise the effectiveness ofthe coolant will be reduced.WARNING
EWA10380
Never attempt to remove the radiatorcap when the engine is hot.
6. Install the coolant reservoir cap.
7. Place the coolant reservoir cap re- tainer in the original position, and
then tighten the bolt to the speci-
fied torque.
8. Install the cowling.
1. Maximum level mark
2. Minimum level mark
1. Coolant reservoir cap retainer bolt
2. Coolant reservoir cap retainer
3. Coolant reservoir capCoolant reservoir capacity (maximum
level): YAMAHA GENUINE COOLANT
0.28 L (0.30 US qt) (0.25 Imp.qt)
Tightening torque:Coolant reservoir cap retainer bolt: 7.0 Nm (0.7 m ·kgf, 5.1 ft ·lbf)
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-13
6
NOTE:
The radiator fan is automatically
switched on or off according to the
coolant temperature in the radia-
tor.
If the engine overheats, see page6-36 for further instructions.
EAU33030
Changing the coolant
WARNING
EWA10380
Never attempt to remove the radiatorcap when the engine is hot.
The coolant must be changed at the in-
tervals specified in the periodic mainte-
nance and lubrication chart. Have a
Yamaha dealer change the coolant.
EAU37661
Cleaning the air filter element The air filter element should be cleaned
at the intervals specified in the periodic
maintenance and lubrication chart.
Clean the air filter element more fre-
quently if you are riding in unusually
wet or dusty areas.
1. Remove panel A. (See page 6-5.)
2. Remove the air filter case cover by
removing the screws and clamp,
and then pull the air filter element
out.3. Lightly tap the air filter element to
remove most of the dust and dirt,
and then blow the remaining dirt
out with compressed air as shown.
If the air filter element is damaged,
replace it.1. Air filter case cover
2. Screw
3. Clamp
1. Air filter element
1. Air filter element
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-14
6 4. Insert the air filter element into the
air filter case.
CAUTION:
ECA10480
Make sure that the air filter ele-
ment is properly seated in the
air filter case.
The engine should never be op-
erated without the air filter ele-
ment installed, otherwise the
piston(s) and/or cylinder(s) maybecome excessively worn.
5. Install the air filter case cover by in-
stalling the clamp and screws.
NOTE:
Make sure that the carburetor air
vent hose is routed as shown.
If dust or water collects in the air fil-
ter check hose, remove the clamp
from it, and then remove the plugto drain the hose.
6. Install the panel.
EAU21280
Adjusting the carburetor The carburetor is an important part of
the engine and requires very sophisti-
cated adjustment. Therefore, most car-
buretor adjustments should be left to a
Yamaha dealer, who has the neces-
sary professional knowledge and expe-
rience. The adjustment described in the
following section, however, may be ser-
viced by the owner as part of routine
maintenance.CAUTION:
ECA10550
The carburetor has been set and ex-
tensively tested at the Yamaha fac-
tory. Changing these settings
without sufficient technical knowl-
edge may result in poor perfor-mance of or damage to the engine.
1. Carburetor air vent hose
1. Air filter check hose
2. Clamp
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-15
6
EAU37520
Adjusting the engine idling
speed The engine idling speed must be
checked and, if necessary, adjusted as
follows at the intervals specified in the
periodic maintenance and lubrication
chart.
The engine should be warm before
making this adjustment.NOTE:
The engine is warm when it quickly
responds to the throttle.
A diagnostic tachometer is neededto make this adjustment.
1. Remove cowling B. (See page
6-5.)
2. Attach the diagnostic tachometer
to the spark plug lead.
3. Check the engine idling speed
and, if necessary, adjust it to spec-
ification by turning the throttle stop
screw. To increase the engine
idling speed, turn the screw in di-
rection (a). To decrease the en-
gine idling speed, turn the screw in
direction (b).
NOTE:
If the specified idling speed cannot be
obtained as described above, have aYamaha dealer make the adjustment.
4. Install the cowling.
EAU21370
Adjusting the throttle cable
free play The throttle cable free play should mea-
sure 3.0–7.0 mm (0.12–0.28 in) at the
throttle grip. Periodically check the
throttle cable free play and, if neces-
sary, adjust it as follows.NOTE:The engine idling speed must be cor-
rectly adjusted before checking and ad-justing the throttle cable free play.
1. Loosen the locknut.
1. Throttle stop screwEngine idling speed:
1300–1500 r/min
1. Throttle cable free play
2. Locknut
3. Adjusting nut
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