Yamaha YZF-R125 Service Manual: Checking the stator coil
1. Disconnect:
- Stator coil coupler (from the wire harness)
2. Check:
Stator coil resistance
Out of specification → Replace the
crankshaft
position sensor/stator assembly.
a. Connect the pocket tester ( 
×
1) to the stator
coil coupler as shown.
b. Measure the stator coil resistance.
Checking the starter motor operation
1. Check:
Starter motor operation
Does not operate → Perform the electric
starting system troubleshooting, starting with
step 4.
Refer to "TROUBLESHOOTING" on page
8-9.
a. Con ...
Checking the rectifier/regulator
1. Check:
Rectifier/regulator output voltage
Out of specification → Replace the
rectifier/
regulator.
a. Set the engine tachometer to the spark plug
lead.
b. Connect the pocket tester ...
Other materials:
Replacing the headlight bulbs
The following procedure applies to the low beam
headlight bulb.
1. Remove:
Headlight bulb cover "1"
2. Remove:
Headlight bulb holder "1"
3. Remove:
Headlight bulb "1"
WARNINGSince the headlight bulb gets extremely
hot,
keep flammable products and your ...
Checking the camshaft sprocket and timing chain guide
1. Check:
Camshaft sprocket
More than 1/4 tooth wear "a" Replace
the
camshaft sprocket, timing chain and crankshaft
as a set.
a. 1/4 tooth
b. Correct
1. Timing chain roller
2. Camshaft sprocket
2. Check:
Timing chain guide (exhaust side)
Damage/wear Replace.
...
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 ...