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:
Removing the throttle body
1. Extract the fuel in the fuel tank through the
fuel tank filler hole with a pump.
2. Disconnect:
Fuel hose
WARNINGCover the fuel hose connections with a
cloth
when disconnecting them. Residual pressure
in the fuel lines could cause fuel to
spurt out when removing the h ...
Troubleshooting charts
Starting problems or poor engine performance
Starting problems or poor engine performance
Engine overheating
WARNING
Do not remove the radiator cap when the engine and radiator are hot.
Scalding hot fluid and steam may be
blown out under pressure, which could cause serious injury. Be ...
Checking the camshaft
1. Check:
Camshaft lobes
Blue discoloration/pitting/scratches
Replace
the camshaft.
2. Measure:
Camshaft lobe dimensions "a" and "b"
Out of specification Replace
the camshaft.
3. Check:
Camshaft oil passage
Obstruction Blow out with
compressed air. ...