Yamaha YZF-R125 Service Manual: Checking and adjusting the steering head
1. Stand the vehicle on a level surface
| WARNING Securely support the vehicle so that there is no danger of it falling over. |
NOTE:
Place the vehicle on a suitable stand so that the front wheel is elevated.
2. Check:
- Steering head
Grasp the bottom of the front fork legs and
gently rock the front fork.
Binding/looseness → Adjust the steering head.
3. Remove:
- Upper bracket Refer to "STEERING HEAD" on page 4-52.
4. Adjust:
- Steering head
a. Remove the lock washer "1", the upper ring nut "2", and the rubber washer "3".
b. Tighten the lower ring nut "4" with a steering nut wrench "5".
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. |
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 4-52.
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:
- Upper bracket Refer to "STEERING HEAD" on page 4-52.
Lubricating the drive chain
The drive chain consists of many interacting
parts. If the drive chain is not maintained properly,
it will wear out quickly. Therefore, the drive
chain should be serviced, especially when the
vehi ...
Checking the front fork
1. Stand the vehicle on a level surface.
WARNINGSecurely support the vehicle so that there
is
no danger of it falling over.
2. Check:
Inner tube
Damage/scratches Replace.
...
Other materials:
Checking the crankshaft position sensor
1. Disconnect:
Crankshaft position sensor coupler
(from the wire harness)
2. Check:
Crankshaft position sensor resistance
Out of specification Replace
the crankshaft
position sensor/stator assembly.
a. Connect the pocket tester ( × 100) to the
crankshaft position sensor c ...
Troubleshooting
Although Yamaha motorcycles receive
a thorough inspection before shipment
from the factory, trouble may occur during
operation. Any problem in the fuel,
compression, or ignition systems, for
example, can cause poor starting and
loss of power.
The following troubleshooting charts
repre ...
Checking the drive chain
1. Measure:
15-link section "a" of the drive chain
Out of specification Replace the drive
chain.
a. Measure the length "a" between the inner
sides of the pins and the length "b" between
the outer sides of the pins on a 15-link section
of the drive chain as shown in the illustration.
...