Yamaha YZF-R125 Service Manual: Checking the cylinder head breather hose
1. Remove:
- Left side panel Refer to "GENERAL CHASSIS" on page 4-1.
2. Check:
- Cylinder head breather hose "1"
Cracks/damage → Replace.
Loose connection → Connect properly.
| CAUTION: Make sure the cylinder head breather hose is routed correctly. |
3. Install:
- Left side panel Refer to "GENERAL CHASSIS" on page 4-1.
Checking the fuel line
1. Remove:
Left side panel
Refer to "GENERAL CHASSIS" on page 4-1.
2. Lift the fuel tank. (Do not disconnect the fuel
hose, drain hose
3. Check:
Fuel hose "1"
Cracks/damage → Replac ...
Checking the exhaust system
1. Check:
Exhaust assembly "1"
Cracks/damage → Replace.
Exhaust pipe gasket "2"
Exhaust gas leaks → Replace.
2. Check:
Tightening torques of the exhaust pipe nuts
"3" an ...
Other materials:
Incorrect engine idling speed
Engine
1. Cylinder and cylinder head
Incorrect valve clearance
Damaged valve train components
2. Air filter
Clogged air filter element
Fuel system
1. Throttle body
Damaged or loose throttle body joint
Improperly adjusted engine idling speed (idle
adjusting screw)
Improper ...
Checking the speed sensor
1. Check:
Speed sensor output voltage
Out of specification → Replace.
a. Connect the pocket tester (DC 20 V) to the
speed sensor coupler (wire harness end) as
shown.
Positive tester probe
gray "1"
Negative tester probe
gray/black "2"
b. Set the main switch to "ON".
c. ...
Supporting the motorcycle
Since this model is not equipped with a
centerstand, follow these precautions
when removing the front and rear
wheel or performing other maintenance
requiring the motorcycle to stand upright.
Check that the motorcycle is in a
stable and level position before starting
any maintenance. A ...