Yamaha YZF-R125 Service Manual: Checking the switches
1. Clutch switch
2. Main switch
3. Front brake light switch
4. Sidestand switch
5. Rear brake light switch
6. Neutral switch
7. Turn signal switch
8. Horn switch
9. Dimmer switch
10.Pass switch
11.Engine stop switch
12.Start switch
Check each switch for continuity with the pocket tester. If the continuity reading is incorrect, check the wiring connections and, if necessary, replace the switch.
| CAUTION: Never insert the tester probes into the
coupler terminal slots "a". Always insert the probes from
the opposite end of the coupler, taking care not to loosen or damage the
leads. |
NOTE:
- Before checking for continuity, set the pocket tester to "0" and to the " × 1" range.
- When checking for continuity, switch back and forth between the switch positions a few times.
The switches and their terminal connections are illustrated as in the following example of the main switch.
The switch positions "a" are shown in the far left column and the switch lead colors "b" are shown in the top row.
The continuity (i. e., a closed circuit) between switch terminals at a given
switch position is indicated by
" 
". There is continuity between
red and brown/blue, and blue/yellow and blue/black when the
switch is set to "ON".
Electrical components
1. Main switch
2. Clutch switch
3. Front brake light switch
4. Ignition coil
5. Throttle body sensor assembly (intake air
pressure sensor, intake air temperature
sensor, throttle position se ...
Checking the bulbs and bulb sockets
NOTE:
Do not check any of the lights that use LEDs.
Check each bulb and bulb socket for damage or
wear, proper connections, and also for continuity
between the terminals.
Damage/wear Repa ...
Other materials:
Incorrect engine idling speed
Engine
1. Cylinder and cylinder head
Incorrect valve clearance
Damaged valve train components
2. Air filter
Clogged air filter element
Fuel system
1. Throttle body
Damaged or loose throttle body joint
Improperly adjusted engine idling speed (idle
adjusting screw)
Improper ...
Aftermarket Parts, Accessories, and Modifications
While you may find aftermarket products
similar in design and quality to
genuine Yamaha accessories, recognize
that some aftermarket accessories
or modifications are not suitable because
of potential safety hazards to you
or others. Installing aftermarket products
or having other modif ...
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. ...