Yamaha YZF-R125 Service Manual: Checking the crankshaft position sensor
1. Disconnect:
- Crankshaft position sensor coupler (from the wire harness)
2. Check:
Crankshaft position sensor resistance
Out of specification
Replace
the crankshaft
position sensor/stator assembly.
a. Connect the pocket tester ( × 100) to the
crankshaft position sensor coupler as shown.
- Positive tester probe
red "1" - Negative tester probe
white "2"
b. Measure the crankshaft position sensor resistance.
Checking the ignition spark gap
1. Check:
Ignition spark gap
Out of specification Perform the
ignition
system troubleshooting, starting with step 5.
Refer to "TROUBLESHOOTING" on page
8-3.
NOTE:
If the ignition spark gap ...
Checking the lean angle sensor
1. Remove:
Lean angle sensor
2. Check:
Lean angle sensor output voltage
Out of specification Replace.
a. Connect the lean angle sensor to the wire
harness.
b. Connect the pocket tester ...
Other materials:
Installing the steering head
1. Lubricate:
Upper bearing
Lower bearing
Bearing races
2. Install:
Lower ring nut
Rubber washer
Upper ring nut
Lock washer
Refer to "CHECKING AND ADJUSTING
THE STEERING HEAD" on page 3-22.
3. Install:
Upper bracket
Steering stem nut
NOTE:
Temporarily tighten t ...
Electrical components
1. Main switch
2. Clutch switch
3. Front brake light switch
4. Ignition coil
5. Throttle body sensor assembly (intake air
pressure sensor, intake air temperature
sensor, throttle position sensor)
6. FID (fast idle solenoid)
7. Rectifier/regulator
8. Lean angle sensor
9. Starting circui ...
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 ...