Yamaha YZF-R125 Service Manual: Introduction

Yamaha YZF-R125 Service Manual / Chassis / Front brake / Introduction

WARNING

Disc brake components rarely require disassembly.

Therefore, always follow these preventive measures:

Never disassemble brake components unless absolutely necessary.
If any connection on the hydraulic brake system is disconnected, the entire brake system must be disassembled, drained, cleaned, properly filled, and bled after reassembly.
Never use solvents on internal brake components.
Use only clean or new brake fluid for cleaning brake components.
Brake fluid may damage painted surfaces and plastic parts. Therefore, always clean up any spilt brake fluid immediately.
Avoid brake fluid coming into contact with the eyes as it can cause serious injury.
FIRST AID FOR BRAKE FLUID ENTERING THE EYES:
Flush with water for 15 minutes and get immediate medical attention.

Checking the front brake disc

1. Remove: Front wheel Refer to "FRONT WHEEL" on page 4-6. 2. Check: Brake disc Damage/galling Replace. 3. Measure: Brake disc deflection Out of specification Correct the b ...

Other materials:

Checking the valves and valve guides
The following procedure applies to all of the valves and valve guides. 1. Measure: Valve-stem-to-valve-guide clearance Out of specification Replace the valve guide. Valve-stem-to-valve-guide clearance = Valve guide inside diameter "a" - Valve stem diameter "b" 2. Replace: ...

Bearings and oil seals
Install bearings "1" and oil seals "2" so that the manufacturer's marks or numbers are visible. When installing oil seals "1", lubricate the oil seal lips with a light coat of lithium-soap-based grease. Oil bearings liberally when installing, if appropriate. CAUTION:Do not spin th ...

Overheating
Engine 1. Clogged coolant passages Cylinder head and piston Heavy carbon buildup 2. Engine oil Incorrect oil level Incorrect oil viscosity Inferior oil quality Cooling system 1. Coolant Low coolant level 2. Radiator Damaged or leaking radiator Faulty radiator cap ...