Yamaha YZF-R125 Service Manual: Circuit diagram
2. Crankshaft position sensor
4. Main fuse
5. Main switch
6. Radiator fan motor fuse
8. Sidestand switch
9. Battery
17.Engine stop switch
19.Intake air pressure sensor
20.Intake air temperature sensor
21.Throttle position sensor
22.Coolant temperature sensor
23.Lean angle sensor
24.Self-diagnosis signal connector
25.ECU (engine control unit)
26.Ignition coil
27.Spark plug
28.FID (fast idle solenoid)
29.Fuel injector
30.Fuel pump
32.Radiator fan motor relay
33.Radiator fan motor
63.Engine trouble warning light
64.Ignition fuse
66.Signaling system fuse
67.Speed sensor
Ecu self-diagnostic function
The ECU is equipped with a self-diagnostic function in order to ensure that
the fuel injection system is
operating normally. If this function detects a malfunction in the system, it
immediately o ...
Other materials:
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
...
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
...
Separating the crankcase
1. Remove:
Crankcase bolts
NOTE:
Loosen each bolt 1/4 of a turn at a time, in stages
and in the proper sequence as shown.
A. Right crankcase
B. Left crankcase
2. Turn:
Shift drum segment
NOTE:
Turn the shift drum segment "1" to the position
shown in the illustration. In this ...