Yamaha YZF-R125 Service Manual: Adjusting the engine idling speed
NOTE:
Prior to adjusting the engine idling speed, the air filter element should be clean, and the engine should have adequate compression.
1. Start the engine and let it warm up for several minutes.
2. Remove:
- Rider seat Refer to "GENERAL CHASSIS" on page 4-1.
3. Lift the fuel tank. (Do not disconnect the fuel hose, fuel drain hose, and couplers.) Refer to "FUEL TANK" on page 7-1.
4. Install:
- Digital tachometer (onto the spark plug lead)
5. Check:
Engine idling speed
Out of specification → Adjust.
6. Remove:
- Right side panel Refer to "GENERAL CHASSIS" on page 4-1.
7. Adjust:
- Engine idling speed
a. Turn the pilot screw "1" in direction "a" or "b" until the specified engine idling speed is obtained.
8. Remove:
- Digital tachometer
9. Install:
- Fuel tank Refer to "FUEL TANK" on page 7-1.
- Right side panel
- Rider seat Refer to "GENERAL CHASSIS" on page 4-1.
10.Adjust:
- Throttle cable free play
Refer to "ADJUSTING THE THROTTLE CABLE
FREE PLAY" on page 3-6.
Adjusting the exhaust gas volume
NOTE:
Be sure to set the CO density level to standard,
and then adjust the exhaust gas volume.
1. Remove:
Rider seat
Refer to "GENERAL CHASSIS" on page 4-1.
2. Set the main switch to "OFF" ...
Adjusting the throttle cable free play
NOTE:
Prior to adjusting the throttle cable free play, the
engine idling speed should be adjusted.
1. Check:
Throttle cable free play "a"
Out of specification →Adjust.
2. Remov ...
Other materials:
Throttle position sensor
1. Check:
Throttle position sensor
a. Connect the digital circuit tester to the terminals
of the throttle body sensor assembly
coupler as shown.
Positive tester probe →
gray/red terminal "1"
Negative tester probe →
gray/black terminal "2"
b. Measure the throttle pos ...
Circuit diagram
4. Main fuse
5. Main switch
9. Battery
14.Neutral switch
25.ECU (engine control unit)
31.Fuel sender
34.Rear brake light switch
35.Front brake light switch
37.Tail/brake light
38.Rear right turn signal light
39.Rear left turn signal light
40.Front right turn signal light
41.Front lef ...
Checking the fuel pressure
1. Check:
Pressure regulator operation
a. Remove the fuel hose connector cover "1"
and disconnect the fuel hose "2" from the fuel
pump.
CAUTION:Although the fuel has been removed from
the fuel tank, be careful when removing the
fuel hose, since there may be fuel remaining
i ...