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:
Intake air temperature sensor
1. Check:
Intake air temperature sensor resistance
Out of specification Replace
the throttle
body.
a. Connect the pocket tester ( ×
1k) to the
throttle body sensor assembly coupler as
shown.
Positive tester probe
brown/white "1"
Negative tester probe
gray/black ...
Ecu self-diagnostic function
The ECU is equipped with a self-diagnostic function in order to ensure that
the fuel injection system is
operating normally. If this function detects a malfunction in the system, it
immediately operates the engine
under substitute characteristics and illuminates the engine trouble warning
li ...
Checking the valve springs
The following procedure applies to all of the
valve springs.
1. Measure:
Valve spring free length "a"
Out of specification Replace the valve
spring.
2. Measure:
Compressed valve spring force "a"
Out of specification Replace the valve
spring.
b. Installed length
3. ...