Yamaha YZF-R125 Service Manual: Unstable handling
Handlebars
- Bent or improperly installed right handlebar
- Bent or improperly installed left handlebar
1. Steering head components
- Improperly installed upper bracket
- Improperly installed lower bracket (improperly tightened ring nut)
- Bent steering stem
- Damaged ball bearing or bearing race
2. Front fork leg(s)
- Uneven oil levels (both front fork legs)
- Unevenly tensioned fork spring (both front fork legs)
- Broken fork spring
- Bent or damaged inner tube
- Bent or damaged outer tube
3. Swingarm
- Worn bearing
- Bent or damaged swingarm
Rear shock absorber assembly
- Faulty rear shock absorber spring
- Leaking oil
Tire(s)
- Uneven tire pressures (front and rear)
- Incorrect tire pressure
- Uneven tire wear
Wheel(s)
- Incorrect wheel balance
- Deformed cast wheel
- Damaged wheel bearing
- Bent or loose wheel axle
- Excessive wheel runout
Frame
- Bent frame
- Damaged steering head pipe
- Improperly installed bearing race
Faulty front fork legs
Leaking oil
- Bent, damaged or rusty inner tube
- Cracked or damaged outer tube
- Improperly installed oil seal
- Damaged oil seal lip
- Incorrect oil level (high)
- Loose damper rod assembly bo ...
Faulty lighting or signaling system
Headlight does not come on
- Wrong headlight bulb
- Too many electrical accessories
- Hard charging
- Incorrect connection
- Improperly grounded circuit
- Poor contacts (main or light switch)
- ...
Other materials:
Tires
To maximize the performance, durability,
and safe operation of your motorcycle,
note the following points regarding
the specified tires.
Tire air pressure
The tire air pressure should be checked
and, if necessary, adjusted before each
ride.
WARNING
Operation of this vehicle with impro ...
Replacing the fuses
Replacing the fuses
Fuse box
Spare fuse
Headlight fuse
Signaling system fuse
Ignition fuse
Radiator fan fuse
Main fuse
The fuse box is located under the rider
seat.
If a fuse is blown, replace it as follows.
Turn the key to "OFF" and turn off
the electrical circuit i ...
Checking the rear shock absorber assembly
1. Check:
Rear shock absorber rod
Bends/damage Replace the rear
shock
absorber assembly.
Rear shock absorber
Oil leaks Replace the rear
shock absorber
assembly.
Spring
Damage/wear Replace the
rear shock absorber
assembly.
Bushing
Damage/wear Replace the rea ...