Yamaha YZF-R125 Owners Manual: Ignition circuit cut-off system
The ignition circuit cut-off system (comprising the sidestand switch, clutch switch and neutral switch) has the following functions.
- It prevents starting when the transmission is in gear and the sidestand is up, but the clutch lever is not pulled.
- It prevents starting when the transmission is in gear and the clutch lever is pulled, but the sidestand is still down.
- It cuts the running engine when the transmission is in gear and the sidestand is moved down.
Periodically check the operation of the ignition circuit cut-off system according to the following procedure.
WARNING
If a malfunction is noted, have a Yamaha
dealer check the system before riding.
Sidestand
The sidestand is located on the left side
of the frame. Raise the sidestand or
lower it with your foot while holding the
vehicle upright.
TIP
The built-in sidestand switch is part of
the ign ...
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 ...
Other materials:
Removing the valves
The following procedure applies to all of the
valves and related components.
NOTE:
Before removing the internal parts of the cylinder
head (e.g., valves, valve springs, valve seats),
make sure the valves properly seal.
1. Check:
Valve sealing
Leakage at the valve seat Check
the valve
...
Checking the spark plug
The spark plug is an important engine
component, which is easy to check.
Since heat and deposits will cause any
spark plug to slowly erode, the spark
plug should be removed and checked
in accordance with the periodic maintenance
and lubrication chart. In addition,
the condition of the ...
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. ...