2008 YAMAHA TTR50 Owners Manual

PERIODIC MAINTENANCE AND MINOR REPAIR
6-12
6 2. To increase the throttle cable free
play, turn the adjusting nut in direc-
tion (a). To decrease the throttle
cable free play, turn the adjusting
nut in direction (b).
3. Tighten the locknut.
EAU21401
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.
EAU39820
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.
WARNING
EWA14380


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
weight of the rider, the riding
speed, and the riding condi-tions.
1. Locknut
2. Throttle cable free play adjusting nut
2 (a)
(b) 1
Standard tire air pressure:
Front:
100 kPa (15 psi) (1.00 kgf/cm²)
Rear:
100 kPa (15 psi) (1.00 kgf/cm²)
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-13
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 sidewall is
cracked, have a Yamaha dealer re-
place the tire immediately.
Tire information
This motorcycle is equipped with spoke
wheels and tube tires.
WARNING
EWA10460


The front and rear tires should
be of the same make and de-
sign, otherwise the handling
characteristics of the vehicle
cannot be guaranteed.


After extensive tests, only the
tires listed below have been ap-
proved for this model byYamaha Motor Co., Ltd.WARNING
EWA14390


Have a Yamaha dealer replace
excessively worn tires. Operat-
ing the motorcycle with exces-sively worn tires decreases
riding stability 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
2. Tire tread depthMinimum tire tread depth (front and
rear):
4.0 mm (0.16 in)
12
Front tire:
Size:
2.50-10 4PR
Manufacturer/model:
CHENG SHIN/KNOBBY
Rear tire:
Size:
2.50-10 4PR
Manufacturer/model:
CHENG SHIN/KNOBBY
U1P682E0.book Page 13 Wednesday, May 23, 2007 9:34 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-14
6
EAU21940
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 characteris-
tics.
EAU40431
Accessories and replacement
parts
WARNING
EWA14481
The accessories or replacement
parts you choose for your vehicle
should be designed specifically for
this model, and they must be se-
curely mounted to maintain the in-
herent stability of the original
design. Genuine Yamaha Parts and
Accessories are designed and test-
ed to be compatible with your vehi-
cle. Yamaha recommends the use of
Genuine Yamaha Parts and Acces-
sories before making a purchase.
Use of non-Yamaha-approved ac-
cessories or replacement parts may
cause loss of handling stability and
riding safety. Since Yamaha cannot
control the quality of accessories or
parts manufactured by other compa-
nies, Yamaha cannot be held liable
for any consequences caused by
the use of items which have notbeen approved by Yamaha.
EAU44661
Adjusting the clutch free play The clutch free play must be checked
and, if necessary, adjusted as follows
at the intervals specified in the periodic
maintenance and lubrication chart.
1. Loosen the locknut.
2. Slowly turn the clutch adjusting
screw in direction (a) until resis-
tance is felt, and then turn it 1/8
turn in direction (b).NOTE:Turning the clutch adjusting screw in di-
rection (a) decreases clutch free play
and turning it in direction (b) increasesclutch free play.1. Locknut
2. Clutch adjusting screw
U1P682E0.book Page 14 Wednesday, May 23, 2007 9:34 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-15
63. Tighten the locknut to the specified
torque.
NOTE:
When tightening the locknut, hold the
clutch adjusting screw with a screwdriv-
er so that it does not turn together withthe locknut.
EAU22130
Adjusting the brake lever free
play The brake lever free play should mea-
sure 10.0–20.0 mm (0.39–0.79 in) as
shown. Periodically check the brake le-
ver free play and, if necessary, adjust it
as follows.
To increase the brake lever free play,
turn the adjusting nut at the brake shoe
plate in direction (a). To decrease the
brake lever free play, turn the adjusting
nut in direction (b).
WARNING
EWA10650
If proper adjustment cannot be ob-
tained as described, have a Yamahadealer make this adjustment.
Tightening torque:
Locknut:
6 Nm (0.6 m·kgf, 4.3 ft·lbf)
1. Brake lever free play
1
1. Brake lever free play adjusting nut
1
(a)
(b)
U1P682E0.book Page 15 Wednesday, May 23, 2007 9:34 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-16
6
EAU44670
Adjusting the brake pedal free
play The brake pedal free play should mea-
sure 10.0–20.0 mm (0.39–0.79 in) at
the brake pedal end as shown. Period-
ically 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).
WARNING
EWA14820


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.
EAU22361
Checking the front and rear
brake shoes Front
Rear
1. Brake pedal free play
1
1. Brake pedal free play adjusting nut
(b) (a)
1
1. Brake shoe wear indicator
2. Brake shoe wear limit line
1. Brake shoe wear indicator
2. Brake shoe wear limit line
2
1
21
U1P682E0.book Page 16 Wednesday, May 23, 2007 9:34 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-17
6The front and rear brake shoes must be
checked for wear at the intervals spec-
ified in the periodic maintenance and
lubrication chart. Each brake is provid-
ed with a wear indicator, which allows
you to check the brake shoe wear with-
out having to disassemble the brake.
To check the brake shoe wear, check
the position of the wear indicator while
applying the brake. If a brake shoe has
worn to the point that the wear indicator
reaches the wear limit line, have a
Yamaha dealer replace the brake
shoes as a set.
EAU22760
Drive chain slack The drive chain slack should be
checked before each ride and adjusted
if necessary.
EAU22773
To check the drive chain slack
1. Place the motorcycle on the side-
stand.NOTE:When checking and adjusting the drive
chain slack, there should be no weighton the motorcycle.
2. Shift the transmission into the neu-
tral position.
3. Move the rear wheel by pushing
the motorcycle to locate the tight-
est portion of the drive chain, and
then measure the drive chain slack
as shown.4. If the drive chain slack is incorrect,
adjust it as follows.
EAU40110
To adjust the drive chain slack
1. Loosen the brake pedal free play
adjusting nut, axle nut, and locknut
at each end of the swingarm.
Drive chain slack:
35.0–45.0 mm (1.38–1.77 in)
1. Drive chain slack
U1P682E0.book Page 17 Wednesday, May 23, 2007 9:34 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-18
6 2. To tighten the drive chain, turn the
adjusting nut at each end of the
swingarm in direction (a). To loos-
en the drive chain, turn the adjust-
ing nut at each end of the
swingarm in direction (b), and then
push the rear wheel forward.
NOTE:Using the alignment marks on each
side of the swingarm, make sure that
both adjusting nuts are in the same po-sition for proper wheel alignment.
CAUTION:
ECA10570
Improper drive chain slack will over-
load the engine as well as other vital
parts of the motorcycle and can lead
to chain slippage or breakage. To
prevent this from occurring, keep
the drive chain slack within thespecified limits.
3. Tighten both locknuts and the axle
nut to the specified torques.4. Adjust the brake pedal free play.
(See page 6-16.)
1. Brake pedal free play adjusting nut
2. Drive chain slack adjusting nut
3. Locknut
1
2
3
1. Axle nut
2. Locknut
3. Drive chain slack adjusting nut
4. Alignment marks
1(b) 4(a)
2
3
Tightening torques:
Locknut:
7.0 Nm (0.7 m·kgf, 5.1 ft·lbf)
Axle nut:
60 Nm (6.0 m·kgf, 43 ft·lbf)
U1P682E0.book Page 18 Wednesday, May 23, 2007 9:34 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-19
6
EAU23013
Cleaning and lubricating the
drive chain The drive chain must be cleaned and
lubricated at the intervals specified in
the periodic maintenance and lubrica-
tion chart, otherwise it will quickly wear
out, especially when riding in dusty or
wet areas. Service the drive chain as
follows.CAUTION:
ECA10581
The drive chain must be lubricated
after washing the motorcycle andriding in the rain.
1. Remove all dirt and mud from the
drive chain with a brush or cloth.NOTE:For a thorough cleaning, have a
Yamaha dealer remove the drive chainand soak it in solvent.
2. Spray Yamaha Chain and Cable
Lube or a high-quality spray-type
drive chain lubricant on both sides
and on the middle of the chain,making sure that all side plates
and rollers have been sufficiently
oiled.
EAU23091
Checking and lubricating the
cables The operation of all control cables and
the condition of the cables should be
checked before each ride, and the ca-
bles and cable ends should be lubricat-
ed if necessary. If a cable is damaged
or does not move smoothly, have a
Yamaha dealer check or replace it.
WARNING
EWA10710
Damage to the outer housing of ca-
bles may result in internal rusting
and cause interference with cable
movement. Replace damaged ca-
bles as soon as possible to preventunsafe conditions.Recommended lubricant:
Yamaha Chain and Cable Lube or
engine oil SAE 10W-30
U1P682E0.book Page 19 Wednesday, May 23, 2007 9:34 AM