Yamaha YZF-R125 Service Manual: Ignition system
Circuit diagram
2. Crankshaft position sensor
4. Main fuse
5. Main switch
8. Sidestand switch
9. Battery
17.Engine stop switch
23.Lean angle sensor
25.ECU (engine control unit)
26.Ignition coil
27.Spark ...
Other materials:
Checking the horn
1. Check:
Horn resistance
Out of specification Replace.
a. Disconnect the horn connectors from the
horn terminals.
b. Connect the pocket tester ( × 1) to the horn
terminals.
Positive tester probe
horn terminal "1"
Negative tester probe
horn terminal "2"
c. Measure t ...
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. ...
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
...