Yamaha YZF-R125 Owners Manual: Checking the front fork
The condition and operation of the front fork must be checked as follows at the intervals specified in the periodic maintenance and lubrication chart.
To check the condition
Check the inner tubes for scratches, damage and excessive oil leakage.
To check the operation
- Place the vehicle on a level surface and hold it in an upright position. WARNING! To avoid injury, securely support the vehicle so there is no danger of it falling over.
- While applying the front brake, push down hard on the handlebars several times to check if the front fork compresses and rebounds smoothly.
Checking the front fork
NOTICE
If any damage is found or the front
fork does not operate smoothly,
have a Yamaha dealer check or repair
it.
Lubricating the swingarm pivots
The swingarm pivots must be lubricated
at the intervals specified in the periodic
maintenance and lubrication chart.
Recommended lubricant:Molybdenum disulfide grease
...
Checking the steering
Worn or loose steering bearings may
cause danger. Therefore, the operation
of the steering must be checked as follows
at the intervals specified in the periodic
maintenance and lubrication
c ...
Other materials:
Checking the speed sensor
1. Check:
Speed sensor output voltage
Out of specification → Replace.
a. Connect the pocket tester (DC 20 V) to the
speed sensor coupler (wire harness end) as
shown.
Positive tester probe
gray "1"
Negative tester probe
gray/black "2"
b. Set the main switch to "ON".
c. ...
Checking the valve seats
The following procedure applies to all of the
valves and valve seats.
1. Eliminate:
Carbon deposits
(from the valve face and valve seat)
2. Check:
Valve seat
Pitting/wear Replace the
cylinder head.
3. Measure:
Valve seat width C "a"
Out of specification Replace
the ...
Checking the cylinder and piston
1. Check:
Piston wall
Cylinder wall
Vertical scratches Replace the
cylinder,
and replace the piston and piston rings as a
set.
2. Measure:
Piston-to-cylinder clearance
a. Measure cylinder bore "C" with the cylinder
bore gauge.
NOTE:
Measure cylinder bore "C" by takin ...