Yamaha YZF-R125 Service Manual: Removing the throttle body
1. Extract the fuel in the fuel tank through the fuel tank filler hole with a pump.
2. Disconnect:
- Fuel hose
| WARNING Cover the fuel hose connections with a cloth when disconnecting them. Residual pressure in the fuel lines could cause fuel to spurt out when removing the hoses. |
NOTE:
- To remove the fuel hose from the fuel injector, slide the fuel hose connector cover "1" on the end of the hose in the direction of the arrow shown, press the two buttons "2" on the sides of the connector, and then remove the hose.
- Remove the fuel hose manually without using any tools.
- Before removing the hose, place a few rags in the area under where it will be removed.
3. Remove:
- Throttle body
| CAUTION: Do not remove the throttle body sensor assembly "1" from the throttle body. |
Checking the fuel injector
1. Check:
- Fuel injector
Damage
Replace.
Throttle body
...
Checking the throttle body
1. Check:
Throttle body
Cracks/damage Replace the
throttle body.
2. Check:
Fuel passages
Obstruction Clean.
a. Wash the throttle body in a petroleum-based
solvent.
Do not us ...
Other materials:
Checking the piston pin
1. Check:
Piston pin
Blue discoloration/grooves
Replace the
piston pin and then check the lubrication system.
2. Measure:
Piston pin outside diameter "a"
Out of specification Replace
the piston pin.
3. Measure:
Piston pin bore diameter "b"
Out of specifica ...
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 ...
Installing the rear brake master cylinder
1. Install:
Copper washers "1"
Brake hose "2"
Rear brake light switch "3"
WARNINGProper brake hose routing is essential to
insure
safe vehicle operation. Refer to "CABLE
ROUTING" on page 2-33.
CAUTION:When installing the brake hose onto the
brake master ...