Yamaha YZF-R125 Owners Manual: Checking the wheel bearings
The front and rear wheel bearings must be checked at the intervals specified in the periodic maintenance and lubrication chart. If there is play in the wheel hub or if the wheel does not turn smoothly, have a Yamaha dealer check the wheel bearings.
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 ...
Battery
A poorly maintained battery will corrode
and discharge quickly. The electrolyte
level, battery lead connections and
breather hose routing should be
checked before each ride and at the interval ...
Other materials:
Installing the piston and cylinder
1. Install:
Top ring "1"
2nd ring "2"
Oil ring expander "3"
Lower oil ring rail "4"
Upper oil ring rail "5"
NOTE:
Be sure to install the piston rings so that the
manufacturer marks or numbers face up.
2. Install:
Piston "1"
Piston pin "2"
Piston pin clips "3"
NOTE:
...
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
...
Troubleshooting
The ignition system fails to operate (no spark or intermittent spark).
NOTE:
Before troubleshooting, remove the following part(s):
1. Seats
2. Fuel tank
3. Right side cover
4. Left side panel
5. Left upper side cowling
...