Yamaha YZF-R15, Service Manual

Page: 91 / 338

3-22 3-23
CHASSIS CHASSIS
NOTE:
Set the torque wrench at a right angle to the
steering nut wrench.
c. Loosen the lower ring nut “4” completely, and
then tighten it to specification with a steering
nut wrench.
WARNING
Do not overtighten the lower ring nut.
Steering nut socket
YSST-721
Lower ring nut (initial tightening
torque)
48 Nm (4.8 m·kg, 35 ft·lb)
Lower ring nut (final tightening
torque)
13 Nm (1.3 m·kg, 9.4 ft·lb)
d. Check the steering head for looseness or
binding by turning the front fork all the way in
both directions. If any binding is felt, remove
the lower bracket and check the upper and
lower bearings.
Refer to “STEERING HEAD” on page 4-49.
e. Install the rubber washer “3”.
f. Install the upper ring nut “2”.
g. Finger tighten the upper ring nut “2”, and then
align the slots of both ring nuts. If necessary,
hold the lower ring nut and tighten the upper
ring nut until their slots are aligned.
NOTE:
Make sure the lock washer tabs “a” sit correctly
in the ring nut slots “b”.
5. Install:
l
Upper bracket
Refer to “STEERING HEAD” on page 4-49.
CHECKING THE FRONT FORK
1. Stand the vehicle on a level surface.
Securely support the vehicle so that there is
no danger of it falling over.
2. Check:
l
Inner tube
Damage/scratches
→ Replace.
l
Oil seal
Oil leakage
→ Replace.
3. Hold the vehicle upright and apply the front
brake.
4. Check:
l
Front fork operation
Push down hard on the handlebar several
times and check if the front fork rebounds
smoothly.
Rough movement
→ Repair.
Refer to “FRONT FORK” on page 4-41.
CHECKING THE TYRES
The following procedure applies to both of the
tyres.
1. Check:
• Tyre pressure
Out of specification → Regulate.
WARNING
Do not use a tube tyre on a wheel de-
signed only for tubeless tyres to avoid tyre
fail-ure and personal injury from sudden
deflation.
1. Tyre tread depth
2. Side wall
3. Wear indicator
WARNING
It is dangerous to ride with a worn-out tyre.
When the tyre tread reaches the wear limit, re-
place the tyre immediately.
2. Check:
l
Tyre surfaces
Damage/wear
→ Replace the tyre.
Tyre air pressure (measured on
cold tyres)
Front
200 kPa (28 psi) (2.00 kgf/cm²)
Rear
225 kPa (33 psi) (2.25 kgf/cm²)
WARNING
The tyre pressure should only be checked
and regulated when the tyre temperature
equals the ambient air temperature.
The tyre pressure must be adjusted accord-
ing to the total weight (including cargo, rid-
er, passenger and accessories) and the
anticipated riding speed.
Operation of an overloaded vehicle could
cause tyre damage, an accident or an injury.
NEVER OVERLOAD THE VEHICLE.
4
5
After extensive tests, the tires listed below
have been approved by YAMAHA for
this model. The front and rear tyres should
always be by the same manufacturer and of
the same design. No guarantee concerning
handling characteristics can be given if a
tyre combination other than one approved
by YAMAHA is used on this vehicle.
Front tyre
Size
80/90 –17 M/C 44P
Manufacturer/model
MRF/ZAPPER