Yamaha YZF-R125 Service Manual: Checking the fuel line
1. Remove:
- Left side panel Refer to "GENERAL CHASSIS" on page 4-1.
2. Lift the fuel tank. (Do not disconnect the fuel hose, drain hose
3. Check:
Fuel hose "1" Cracks/damage → Replace.
Loose connection Connect properly.
4. Install:
- Fuel tank Refer to "FUEL TANK" on page 7-1.
- Left side panel Refer to "GENERAL CHASSIS" on page 4-1.
Checking the throttle body joint and air filter case joint
1. Remove:
Right lower side cowling
Left lower side cowling
Refer to "GENERAL CHASSIS" on page 4-1.
2. Check:
Throttle body joint "1"
Air filter case joint "2"
Cracks/damage Replace ...
Checking the cylinder head breather hose
1. Remove:
Left side panel
Refer to "GENERAL CHASSIS" on page 4-1.
2. Check:
Cylinder head breather hose "1"
Cracks/damage → Replace.
Loose connection → Connect properly ...
Other materials:
Checking the cylinder head
1. Eliminate:
Combustion chamber carbon deposits
(with a rounded scraper)
NOTE:
Do not use a sharp instrument to avoid damaging
or scratching:
Spark plug bore threads
Valve seats
2. Check:
Cylinder head
Damage/scratches Replace.
Cylinder head water jacket
Min ...
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 ...
Aftermarket Parts, Accessories, and Modifications
While you may find aftermarket products
similar in design and quality to
genuine Yamaha accessories, recognize
that some aftermarket accessories
or modifications are not suitable because
of potential safety hazards to you
or others. Installing aftermarket products
or having other modif ...