Yamaha YZF-R125 Service Manual: Electric starting system
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 pan ...
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 ...
Other materials:
Checking the camshaft
1. Check:
Camshaft lobes
Blue discoloration/pitting/scratches
Replace
the camshaft.
2. Measure:
Camshaft lobe dimensions "a" and "b"
Out of specification Replace
the camshaft.
3. Check:
Camshaft oil passage
Obstruction Blow out with
compressed air. ...
Installing the crankshaft
1. Install:
Crankshaft "1"
NOTE:
Install the crankshaft with the crankshaft installer
pot "2", crankshaft installer bolt "3", adapter
(M12) "4" and spacer (crankshaft installer) "5".
CAUTION:To avoid scratching the crankshaft and to
ease the installation procedure, lubricate ...
Removing the primary drive gear and balancer gears
1. Loosen:
Primary drive gear nut "1"
NOTE:
Place the aluminum plate "a" between the balancer
drive gear "2" and the balancer driven
gear "3", and then loosen the primary drive gear
nut.
2. Straighten the lock washer tab.
3. Loosen:
Balancer driven gear nut "1"
NOTE:
Place ...