Yamaha YZF-R125 Owners Manual: Operation and important riding points
Read the Owner's Manual carefully to become familiar with all controls. If there is a control or function you do not understand, ask your Yamaha dealer.
WARNING
Failure to familiarize yourself with
the controls can lead to loss of control,
which could cause an accident
or injury.
TIP
This model is equipped with a lean angle
sensor to stop the engine in case of
a turnover. To start the engine after a
turnover, be sure to turn the main
switch to "OFF" and then to "ON". Failing
to do so will prevent the engine from
starting even though the engine will
crank when pushing the start switch.
For your safety - pre-operation checks
Inspect your vehicle each time you use it to make sure the vehicle is in safe
operating condition. Always follow the inspection
and maintenance procedures and schedules described in the Owner's Ma ...
Starting the engine
In order for the ignition circuit cut-off
system to enable starting, one of the
following conditions must be met:
The transmission is in the neutral
position.
The transmission is in gear ...
Other materials:
Incorrect engine idling speed
Engine
1. Cylinder and cylinder head
Incorrect valve clearance
Damaged valve train components
2. Air filter
Clogged air filter element
Fuel system
1. Throttle body
Damaged or loose throttle body joint
Improperly adjusted engine idling speed (idle
adjusting screw)
Improper ...
Checking the timing chain tensioner
1. Check:
Timing chain tensioner
Cracks/damage/rough movement Replace.
a. Lightly press the timing chain tensioner rod
into the timing chain tensioner housing by
hand.
NOTE:
While pressing the timing chain tensioner rod,
wind it clockwise with a thin screwdriver "1" until
it stops.
b. ...
Checking the rectifier/regulator
1. Check:
Rectifier/regulator output voltage
Out of specification → Replace the
rectifier/
regulator.
a. Set the engine tachometer to the spark plug
lead.
b. Connect the pocket tester (DC 20 V) to the
rectifier/regulator coupler as shown.
Positive tester probe
red "1"
Negat ...