Yamaha YZF-R125 Service Manual: 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
Periodic maintenance and lubrication chart
NOTE:
The annual checks must be performed every year, except if a
kilometer-based maintenance,
or for the UK, a mileage-based maintenance, is performed instead.
From 30000 km (17500 mi), re ...
Adjusting the valve clearance
The following procedure applies to all of the
valves.
NOTE:
Valve clearance adjustment should be made
on a cold engine, at room temperature.
When the valve clearance is to be measured or
a ...
Other materials:
Faulty clutch
Clutch slips
1. Clutch
Improperly assembled clutch
Improperly adjusted clutch cable
Loose or fatigued clutch spring
Worn friction plate
Worn clutch plate
2. Engine oil
Incorrect oil level
Incorrect oil viscosity (low)
Deteriorated oil
Clutch drags
1. Clutch
Unevenly t ...
Checking the engine oil level
1. Stand the vehicle on a level surface.
NOTE:
Place the vehicle on a suitable stand.
Make sure the vehicle is upright.
2. Start the engine, warm it up for several minutes,
and then turn it off.
3. Check:
Engine oil level
The engine oil level should be between the
minimum level ...
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 ...