Yamaha YZF-R125 Service Manual: Removing the swingarm
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 rear wheel is elevated.
2. Measure:
- Swingarm side play
- Swingarm vertical movement
a. Measure the tightening torque of the pivot
shaft nut. 
b. Measure the swingarm side play "A" by moving the swingarm from side to side.
c. If the swingarm side play is out of specification,
check the spacers, bearings, and dust
covers. 
3. Remove:
- Pivot shaft nut
- Pivot shaft
- Swingarm "1"
- Swingarm adjusting collar "2"
a. Loosen the pivot shaft nut.
b. Fully turn in the swingarm adjusting collar so that it contacts the frame "3".
c. Remove the pivot shaft nut, washer, pivot shaft and swingarm.
Swingarm
...
Checking the swingarm
1. Check:
Swingarm
Bends/cracks/damage
Replace.
2. Check:
Pivot shaft
Roll the pivot shaft on a flat surface.
Bends Replace.
WARNINGDo not attempt to straighten ...
Other materials:
Checking the starter motor
1. Check:
Commutator
Dirt Clean with 600 grit
sandpaper.
2. Measure:
Commutator diameter "a"
Out of specification Replace
the starter
motor.
3. Measure:
Mica undercut "a"
Out of specification Scrape
the mica to the
proper measurement with a hacksaw blade
...
Checking the turn signal relay
1. Check:
Turn signal relay input voltage
Out of specification →The wiring circuit
from
the main switch to the turn signal relay coupler
is faulty and must be repaired.
a. Connect the pocket tester (DC 20 V) to the
turn signal relay terminal as shown.
- Positive tester probe
b ...
Cast wheels
To maximize the performance, durability,
and safe operation of your vehicle,
note the following points regarding the
specified wheels.
The wheel rims should be checked
for cracks, bends or warpage before
each ride. If any damage is
found, have a Yamaha dealer replace
the wheel. ...