Yamaha YZF-R125 Service Manual: Starting circuit cut-off system operation
If the engine stop switch is set to "
" and the main switch is set to
"ON" (both switches are closed), the
starter motor can only operate if at least one of the following conditions is
met:
- The transmission is in neutral (the neutral switch is closed).
- The clutch lever is pulled to the handlebar (the clutch switch is closed) and the sidestand is up (the sidestand switch is closed).
The starting circuit cut-off relay prevents the starter motor from operating
when neither of these conditions
has been met. In this instance, the starting circuit cut-off relay is open so
current cannot reach the
starter motor. When at least one of the above conditions has been met, the
starting circuit cut-off relay
is closed and the engine can be started by pressing the start switch "
".
a. WHEN THE TRANSMISSION IS IN NEUTRAL
b. WHEN CLUTCH LEVER IS PULLED TO THE HANDLEBAR AND THE SIDESTAND IS UP
1. Battery
2. Main fuse
3. Main switch
4. Ignition fuse
5. Engine stop switch
6. Starting circuit cut-off relay
7. Clutch switch
8. Sidestand switch
9. Diode
10.Neutral switch
11.Start switch
12.Starter relay
13.Starter motor
Circuit diagram
4. Main fuse
5. Main switch
7. Clutch switch
8. Sidestand switch
9. Battery
10.Starter relay
11.Starter motor
12.Starting circuit cut-off relay
13.Diode
14.Neutral switch
16.Start switch ...
Troubleshooting
The starter motor fails to turn.
NOTE:
Before troubleshooting, remove the following part(s):
1. Seats
2. Fuel tank
3. Left lower side cowling
4. Left upper side cowling
...
Other materials:
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 t ...
Checking the spark plug cap
1. Check:
Spark plug cap resistance
Out of specification Replace.
a. Remove the spark plug cap from the spark
plug lead.
b. Connect the pocket tester ( × 1k)
to the
spark plug cap as shown.
c. Measure the spark plug cap resistance. ...
Installing the generator
1. Install:
Woodruff key
Generator rotor
Washer
Generator rotor nut
NOTE:
Clean the tapered portion of the crankshaft and
the generator rotor hub.
When installing the generator rotor, make sure
the woodruff key is properly sealed in the keyway
of the crankshaft.
2. Tighte ...