Yamaha YZF-R125 Service Manual: Periodic checks and adjustments
- Periodic maintenance
- Engine
- Adjusting the valve clearance
- Adjusting the exhaust gas volume
- Adjusting the engine idling speed
- Adjusting the throttle cable free play
- Checking the spark plug
- Checking the ignition timing
- Measuring the compression pressure
- Checking the engine oil level
- Changing the engine oil
- Adjusting the clutch cable free play
- Cleaning the air filter element
- Checking the throttle body joint and air filter case joint
- Checking the fuel line
- Checking the cylinder head breather hose
- Checking the exhaust system
- Checking the coolant level
- Checking the cooling system
- Changing the coolant
- Chassis
- Adjusting the rear disc brake
- Checking the brake fluid level
- Checking the front brake pads
- Checking the rear brake pads
- Checking the front brake hose
- Checking the rear brake hose
- Bleeding the hydraulic brake system
- Adjusting the drive chain slack
- Lubricating the drive chain
- Checking and adjusting the steering head
- Checking the front fork
- Checking the tires
- Checking the wheels
- Checking and lubricating the cables
- Electrical system
Cable routing
Front brake light switch lead
Right handlebar switch lead
Throttle cable
Main switch
Clutch cable
Clutch switch lead
Left handlebar switch lead
Sub-wire harness
Horn
Speed sen ...
Other materials:
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 (DC 20 V) to the
rectifier/regulator coupler as shown.
Positive tester probe
red "1"
Negat ...
Troubleshooting charts
Starting problems or poor engine performance
Starting problems or poor engine performance
Engine overheating
WARNING
Do not remove the radiator cap when the engine and radiator are hot.
Scalding hot fluid and steam may be
blown out under pressure, which could cause serious injury. Be ...
Checking the camshaft
1. Check:
Camshaft lobes
Blue discoloration/pitting/scratches
Replace
the camshaft.
2. Measure:
Camshaft lobe dimensions "a" and "b"
Out of specification Replace
the camshaft.
3. Check:
Camshaft oil passage
Obstruction Blow out with
compressed air. ...