Page 38 of 80

PERIODIC MAINTENANCE AND MINOR REPAIR
6-6
2
3
4
5
67
8
9
To install the panel
Place the panel in the original position.
EAU19601
Checking the spark plug
The spark plug is an important engine
component, which is easy to check.
Since heat and deposits will cause any
spark plug to slowly erode, the spark
plug should be removed and checked
in accordance with the periodic mainte-
nance and lubrication chart. In addition,
the condition of the spark plug can re-
veal the condition of the engine.
To remove the spark plug
1. Remove the spark plug cap.
2. Remove the spark plug as shown,
with the spark plug wrench includ-
ed in the owner’s tool kit.
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 a
Yamaha dealer check the vehicle.
2. Check the spark plug for electrode
erosion and excessive carbon or
other deposits, and replace it if
1. Panel B
1
1. Spark plug cap
1
1. Spark plug wrench
1
Page 39 of 80

PERIODIC MAINTENANCE AND MINOR REPAIR
6-7
1
2
3
4
5
6
7
8
9
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 thespark 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.
EAU19792
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 cleaned at the intervals specified
in the periodic maintenance and lubri-
cation chart.
To check the engine oil level
1. Place the vehicle on a level sur-
face and hold it in an upright posi-
tion.
NOTE:
Make sure that the vehicle is positioned
straight up when checking the oil level.
A slight tilt to the side can result in a
false 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, and then check the oil level
through the check window located
at the bottom-right side of the Specified spark plug:
NGK/DR8EA
DENSO/X24ESR-U
1. Spark plug gap
Spark plug gap:
0.6–0.7 mm (0.024–0.028 in)
1
Tightening torque:
Spark plug:
17.5 Nm (1.75 m·kgf,
12.5 ft·lbf)
Page 40 of 80
PERIODIC MAINTENANCE AND MINOR REPAIR
6-8
2
3
4
5
67
8
9
crankcase.
NOTE:
The engine oil should be between the
minimum and maximum level marks.
4. If the engine oil is below the mini-
mum level mark, add sufficient oil
of the recommended type to raise
it to the correct level.
To change the engine oil (with or
without oil filter element cleaning)
1. Start the engine, warm it up for
several minutes, and then turn it
off.
2. Place an oil pan under the engineto collect the used oil.
3. Remove the engine oil filler cap
and drain bolt to drain the oil from
the crankcase.
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.
1. Engine oil level check window
2. Maximum level mark
3. Minimum level mark
2
3 1
1. Engine oil filler cap
1
1. Engine oil drain bolt
1
Page 41 of 80

PERIODIC MAINTENANCE AND MINOR REPAIR
6-9
1
2
3
4
5
6
7
8
9
NOTE:
Skip steps 4–9 if the oil filter element is
not being cleaned.
4. Remove the oil filter element drain
bolt to drain the oil from the oil filter
element.5. Remove the oil filter element cover
by removing the bolts.
6. Remove the oil filter element and
O-rings.7. Check the O-ring for damage and
replace it if necessary.
8. Clean the oil filter element with sol-
vent, and then install it.
NOTE:
Check the oil filter element for damage
and replace it if necessary.
9. Install the oil filter element cover by
installing the bolts and the drain
bolt, then tightening them to the
specified torques.
NOTE:
Make sure that the O-rings are properly
seated.
10. Clean the oil strainer with solvent,
and then check it for damage and
replace it if necessary.
11. Install the oil strainer, compression
spring, O-ring and engine oil drain
1. O-ring
2. Compression spring
3. Oil strainer
3
21
1. Oil filter element cover
2. Bolt
3. Oil filter element drain bolt
1. Oil filter element
2. O-ring
1
3
2(×2)
1 2
2
Tightening torques:
Oil filter element cover bolt:
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Oil filter element drain bolt:
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Page 42 of 80

PERIODIC MAINTENANCE AND MINOR REPAIR
6-10
2
3
4
5
67
8
9
bolt, and then tighten the drain bolt
to the specified torque.
12. 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. Do
not 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.
13. 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.
14. Turn the engine off, and then
check the oil level and correct it if
necessary.
EAU20830
Cleaning the air filter element
and check hose
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. In addition, the air
filter check hose must be frequently
checked and cleaned if necessary.
To clean the air filter element
1. Remove panel A. (See page 6-5.)
2. Remove the air filter case cover by
removing the screws.
3. Pull the air filter element out.
Tightening torque:
Engine oil drain bolt:
43 Nm (4.3 m·kgf, 31 ft·lbf)
Recommended engine oil:
See page 8-1.
Oil quantity:
Without oil filter element removal:
1.00 L (1.06 US qt)
(0.88 Imp.qt)
With oil filter element removal:
1.10 L (1.16 US qt)
(0.97 Imp.qt)
1. Air filter case cover
2. Screw
1
2(×2)
2(×2)
Page 43 of 80

PERIODIC MAINTENANCE AND MINOR REPAIR
6-11
1
2
3
4
5
6
7
8
9
4. Remove the sponge material from
the air filter element frame, clean it
with solvent, and then squeeze the
remaining solvent out.
5. Apply oil of the recommended type
to the entire surface of the spongematerial, and then squeeze the ex-
cess oil out.
NOTE:
The sponge material should be wet but
not dripping.
6. Pull the sponge material over the
air filter element frame.
7. Insert the 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) may
become excessively worn.
8. Install the air filter case cover by in-
stalling the screws.
9. Install the panel.
To clean the air filter check hose
1. Check the hose at the bottom of
the air filter case for accumulated
dirt or water.
2. If dirt or water is visible, remove
the hose, clean it, and then install
it.
1. Sponge material
2. Air filter element frame
1
2
Recommended oil:
Engine oil
1. Hose
1
Page 44 of 80

PERIODIC MAINTENANCE AND MINOR REPAIR
6-12
2
3
4
5
67
8
9
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.
EAU21330
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.
NOTE:
A diagnostic tachometer is needed to
make this adjustment.
1. Attach the tachometer to the spark
plug lead.
2. Start the engine and warm it up
for several minutes at
1,000–2,000 r/min while occa-
sionally revving it to
4,000–5,000 r/min.
NOTE:
The engine is warm when it quickly re-
sponds to the throttle.
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 a
Yamaha dealer make the adjustment.
1. Throttle stop screw
Engine idling speed:
1350–1550 r/min
(a)
1
(b)
Page 45 of 80

PERIODIC MAINTENANCE AND MINOR REPAIR
6-13
1
2
3
4
5
6
7
8
9
EAU21380
Adjusting the throttle cable
free play
The throttle cable free play should mea-
sure at the throttle grip. Periodically
check the throttle cable free play and, if
necessary, have a Yamaha dealer ad-
just it.
EAU21400
Adjusting the valve clearance
The valve clearance changes with use,
resulting in improper air-fuel mixture
and/or engine noise. To prevent this
from occurring, the valve clearance
must be adjusted by a Yamaha dealer
at the intervals specified in the periodic
maintenance and lubrication chart.
EAU21570
Tires
To maximize the performance, durabil-
ity, and safe operation of your motorcy-
cle, note the following points regarding
the specified tires.
Tire air pressure
The tire air pressure should be checked
and, if necessary, adjusted before each
ride.
WARNING
EWA10500
The tire air pressure must be
checked and adjusted on cold
tires (i.e., when the temperature
of the tires equals the ambient
temperature).
The tire air pressure must be ad-
justed in accordance with the
riding speed and with the total
weight of rider, passenger, car-
go, and accessories approved
for this model.
1. Throttle cable free play
1