Yamaha YZF-R125 Service Manual: Intake air pressure sensor
1. Check:
- Intake air pressure sensor output voltage
Out of specification Replace the throttle
body.
a. Connect the pocket tester (DC 20 V) to the
throttle body sensor assembly coupler as
shown.
- Positive tester probe
pink/white "1" - Negative tester probe
gray/black "2"
b. Set the main switch to "ON".
c. Measure the intake air pressure sensor output voltage.
Throttle position sensor
1. Check:
Throttle position sensor
a. Connect the digital circuit tester to the terminals
of the throttle body sensor assembly
coupler as shown.
Positive tester probe →
gray/red t ...
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 co ...
Other materials:
Starting failures
Engine
1. Cylinder and cylinder head
- Loose spark plug
- Loose cylinder head or cylinder
- Damaged cylinder head gasket
- Damaged cylinder gasket
- Worn or damaged cylinder
- Incorrect valve clearance
- Improperly sealed valve
- Incorrect valve-to-valve-seat contact
- Incorrect valve timi ...
Checking the front fork
The condition and operation of the front
fork must be checked as follows at the
intervals specified in the periodic maintenance
and lubrication chart.
To check the condition
Check the inner tubes for scratches,
damage and excessive oil leakage.
To check the operation
Place the vehicle ...
Checking the clutch boss
1. Check:
Clutch boss splines
Damage/pitting/wear Replace the
clutch
boss.
NOTE:
Pitting on the clutch boss splines will cause erratic
clutch operation.
Checking the pressure plate
1. Check:
Pressure plate
Cracks/damage Replace.
Checking the clutch push lever and short clutch push ...