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:
Checking the cylinder and piston
1. Check:
Piston wall
Cylinder wall
Vertical scratches Replace the
cylinder,
and replace the piston and piston rings as a
set.
2. Measure:
Piston-to-cylinder clearance
a. Measure cylinder bore "C" with the cylinder
bore gauge.
NOTE:
Measure cylinder bore "C" by takin ...
Checking the spark plug
The spark plug is an important engine
component, which is easy to check.
Since heat and deposits will cause any
spark plug to slowly erode, the spark
plug should be removed and checked
in accordance with the periodic maintenance
and lubrication chart. In addition,
the condition of the ...
Checking the valves and valve guides
The following procedure applies to all of the
valves and valve guides.
1. Measure:
Valve-stem-to-valve-guide clearance
Out of specification Replace the
valve
guide.
Valve-stem-to-valve-guide clearance =
Valve guide inside diameter "a" -
Valve stem diameter "b"
2. Replace:
...