

Installing the rear brake master cylinder
Removing the handlebarsOverheating
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
...
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 ...
Introduction
Welcome to the Yamaha world of motorcycling!
As the owner of the YZF-R125, you are benefiting from Yamaha's vast
experience and newest technology regarding the design
and manufacture of high-quality products, which have earned Yamaha a reputation
for dependability.
Please take the time to re ...