
PERIODIC MAINTENANCE AND MINOR REPAIR
6-14
66. Remove the clamp from the air fil-
ter check hose, and then remove
the plug from the check hose to
drain any accumulated water.
7. Install the plug into the check
hose, and then install the clamp.
EC000082*
CAUTION:_
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
pistons and/or cylinders may
become excessively worn.
_8. Install the air filter case cover by
installing the screws. 9. Connect the hose.
10. Install the air filter case by insert-
ing the projection into the grom-
met, installing the bolts, then
tightening the clamp screw.
1. Plug
2. Clamp
3. Air filter check hose
1. Projection
2. Grommet
3. Hose
E_5kr.book Page 14 Friday, December 14, 2001 11:33 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-15
6
EAU00629
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
serviced by the owner as part of routine
maintenance.
EC000094
CAUTION:_ 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. _
EAU01168
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 occasionally rev-
ving 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 engine
idling speed, turn the screw in di-
rection
b.NOTE:_ If the specified idling speed cannot be
obtained as described above, have a
Yamaha dealer make the adjustment. _1. Throttle stop screwEngine idling speed:
1,200–1,400 r/min
E_5kr.book Page 15 Friday, December 14, 2001 11:33 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-16
6
EAU00635
Adjusting the throttle cable
free play The throttle cable free play should
measure 3–5 mm at the throttle grip.
Periodically check the throttle cable
free play and, if necessary, have a
Yamaha dealer adjust it.
EAU00637
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.
EAU04463
Tires To maximize the performance, durabil-
ity, and safe operation of your motor-
cycle, 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.
EW000082
WARNING
_
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
adjusted in accordance with the
riding speed and with the total
weight of rider, passenger, car-
go, and accessories approved
for this model.
_
a. Throttle cable free playE_5kr.book Page 16 Friday, December 14, 2001 11:33 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-17
6
CE-21E
CE-07EEWA00012
WARNING
_ Because loading has an enormous
impact on the handling, braking,
performance and safety characteris-
tics of your motorcycle, you should
keep the following precautions in
mind.
NEVER OVERLOAD THE
MOTORCYCLE! Operation of an
overloaded motorcycle may re-
sult in tire damage, loss of con-
trol, or severe injury. Make sure
that the total weight of rider,
passenger, cargo, and accesso-
ries does not exceed the speci-
fied maximum load for the
vehicle.
Do not carry along loosely
packed items, which can shift
during a ride.
Securely pack the heaviest
items close to the center of the
motorcycle and distribute the
weight evenly on both sides.
Adjust the suspension and tire
air pressure with regard to the
load.
Check the tire condition and air
pressure before each ride.
_
Tire air pressure
(measured on cold tires)
Load* Front Rear
Up to 90 kg175 kPa
(1.75 kgf/cm
2,
1.75 bar)200 kPa
(2.00 kgf/cm
2,
2.00 bar)
90 kg–maximum225 kPa
(2.25 kgf/cm
2,
2.25 bar)225 kPa
(2.25 kgf/cm
2,
2.25 bar)
Maximum load* 180 kg
* Total weight of rider, passenger, cargo and
accessories
E_5kr.book Page 17 Friday, December 14, 2001 11:33 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-18
6Tire inspection
The tires must be checked before each
ride. If the center tread depth reaches
the specified limit, if the tire has a nail
or glass fragments in it, or if the side-
wall is cracked, have a Yamaha dealer
replace the tire immediately.
CE-08ENOTE:_ The tire tread depth limits may differ
from country to country. Always comply
with the local regulations. _
Tire information
This motorcycle is equipped with tube
tires.
EW000078
WARNING
_
The front and rear tires should
be of the same make and de-
sign, otherwise the handling
characteristics of the motor-
cycle cannot be guaranteed.
After extensive tests, only the
tires listed below have been ap-
proved for this model by
Yamaha Motor Co., Ltd.
_CE-10EEAU00681
WARNING
_
Have a Yamaha dealer replace
excessively worn tires. Besides
being illegal, operating the
motorcycle with excessively
worn tires decreases riding sta-
bility and can lead to loss of
control.
The replacement of all wheel-
and brake-related parts, includ-
ing the tires, should be left to a
Yamaha dealer, who has the
necessary professional knowl-
edge and experience.
It is not recommended to patch
a punctured tube. If unavoid-
able, however, patch the tube
very carefully and replace it as
soon as possible with a high-
quality product.
_
1. Tire sidewall
a. Tire tread depthMinimum tire tread depth
(front and rear)1.6 mm
FRONT
Manufacturer Size Model
CHENG SHIN80/100-18 47P
C-916
80/100-18 M/C 47P
IRC80/100-18 47P
MARBELLA
NF27
80/100-18 M/C 47P
REAR
Manufacturer Size Model
CHENG SHIN 130/90-15 M/C 66P C-915
IRC 130/90-15 M/C 66PMARBELLA
NR31
E_5kr.book Page 18 Friday, December 14, 2001 11:33 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-19
6
EAU00685
Spoke wheels To maximize the performance, durabil-
ity, and safe operation of your motor-
cycle, note the following points
regarding the specified wheels.
The wheel rims should be checked
for cracks, bends or warpage, and
the spokes for looseness or dam-
age before each ride. If any dam-
age is found, have a Yamaha
dealer replace the wheel. Do not
attempt even the smallest repair to
the wheel. A deformed or cracked
wheel must be replaced.
The wheel should be balanced
whenever either the tire or wheel
has been changed or replaced. An
unbalanced wheel can result in
poor performance, adverse han-
dling characteristics, and a short-
ened tire life.
Ride at moderate speeds after
changing a tire since the tire sur-
face must first be “broken in” for it to
develop its optimal characteristics.
EAU00694
Adjusting the clutch lever free
play The clutch lever free play should mea-
sure 5–10 mm as shown. Periodically
check the clutch lever free play and, if
necessary, adjust it as follows.
1. Loosen the locknut at the clutch
lever.
2. To increase the clutch lever free
play, turn the adjusting bolt in di-
rection
a. To decrease the clutch
lever free play, turn the adjusting
bolt in direction
b.3. If the specified clutch lever free
play could be obtained as de-
scribed above, tighten the locknut
and skip the rest of the procedure,
otherwise proceed as follows.
4. Fully turn the adjusting bolt at the
clutch lever in direction
a to loos-
en the clutch cable.
5. Loosen the locknut at the
crankcase.
6. To increase the clutch lever free
play, turn the adjusting nut in di-
rection
a. To decrease the clutch
lever free play, turn the adjusting
nut in direction
b.
7. Tighten the locknut at the clutch
lever and the crankcase.1. Locknut
2. Clutch lever free play adjusting bolt
c. Clutch lever free play
1. Locknut
2. Clutch lever free play adjusting nut
E_5kr.book Page 19 Friday, December 14, 2001 11:33 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-20
6
EAU00696
Adjusting the brake lever free
play The brake lever free play should mea-
sure 5–8 mm as shown. Periodically
check the brake lever free play and, if
necessary, adjust it as follows.
1. Loosen the locknut at the brake
lever.
2. To increase the brake lever free
play, turn the adjusting bolt in di-
rection
a. To decrease the brake
lever free play, turn the adjusting
bolt in direction
b.
3. Tighten the locknut.
EW000099
WARNING
_
After adjusting the brake lever
free play, check the free play
and make sure that the brake is
working properly.
A soft or spongy feeling in the
brake lever can indicate the
presence of air in the hydraulic
system. If there is air in the hy-
draulic system, have a Yamaha
dealer bleed the system before
operating the motorcycle. Air in
the hydraulic system will dimin-
ish the braking performance,
which may result in loss of con-
trol and an accident.
_
EAU03778
Adjusting the brake pedal
position and free play
EW000104
WARNING
_ It is advisable to have a Yamaha
dealer make these adjustments. _Brake pedal position
The top of the brake pedal should be
positioned approximately 77 mm above
the top of the footrest as shown. Peri-
odically check the brake pedal position
and, if necessary, adjust it as follows.
1. Locknut
2. Brake lever free play adjusting bolt
c. Brake lever free play
1. Footrest
a. Distance between brake pedal and footrest
b. Brake pedal free play
E_5kr.book Page 20 Friday, December 14, 2001 11:33 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-21
6 1. Loosen the locknut at the brake
pedal.
2. To raise the brake pedal, turn the
adjusting bolt in direction
a. To
lower the brake pedal, turn the ad-
justing bolt in direction
b.
3. Tighten the locknut.
EWA00044
WARNING
_ After adjusting the brake pedal posi-
tion, the brake pedal free play must
be adjusted. _
Brake pedal free play
The brake pedal free play should mea-
sure 20–30 mm at the brake pedal end.
Periodically check the brake pedal free
play and, if necessary, adjust it as
follows.
To increase the brake pedal free play,
turn the adjusting nut at the brake rod
in direction
a. To decrease the brake
pedal free play, turn the adjusting nut in
direction
b.
EW000106
WARNING
_
After adjusting the drive chain
slack or removing and installing
the rear wheel, always check
the brake pedal free play.
If proper adjustment cannot be
obtained as described, have a
Yamaha dealer make this ad-
justment.
After adjusting the brake pedal
free play, check the operation of
the brake light.
_
1. Brake pedal position adjusting bolt
2. Locknut
1. Brake pedal free play adjusting nut
E_5kr.book Page 21 Friday, December 14, 2001 11:33 AM