Yamaha YZF-R125 Service Manual: 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
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:
...
Charging system
...
Other materials:
Installing the shift shaft
1. Install:
Stopper lever "1"
Stopper lever spring "2"
NOTE:
Install the stopper lever spring as shown in the
illustration.
Hook the ends of the stopper lever spring onto
the stopper lever and the crankcase boss "3".
Mesh the stopper lever with the shift drum segment
assembly. ...
Overheating
Engine
1. Clogged coolant passages
Cylinder head and piston
Heavy carbon buildup
2. Engine oil
Incorrect oil level
Incorrect oil viscosity
Inferior oil quality
Cooling system
1. Coolant
Low coolant level
2. Radiator
Damaged or leaking radiator
Faulty radiator cap
...
Checking the cylinder head breather hose
1. Remove:
Left side panel
Refer to "GENERAL CHASSIS" on page 4-1.
2. Check:
Cylinder head breather hose "1"
Cracks/damage → Replace.
Loose connection → Connect properly.
CAUTION:Make sure the cylinder head
breather hose is
routed correctly.
...