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:
Rear wheel
To remove the rear wheel
WARNING
To avoid injury, securely support the
vehicle so there is no danger of it
falling over.
Loosen the axle nut.
Axle nut
Drive chain slack adjusting bolt
Locknut
Brake caliper
Lift the rear wheel off the ground
according to the pr ...
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 ...
Troubleshooting
The ignition system fails to operate (no spark or intermittent spark).
NOTE:
Before troubleshooting, remove the following part(s):
1. Seats
2. Fuel tank
3. Right side cover
4. Left side panel
5. Left upper side cowling
...