Yamaha YZF-R125 Service Manual: Poor medium-and-high-speed performance
Refer to "STARTING FAILURES" on page 9-1.
Engine
1. Air filter
- Clogged air filter element
Fuel system
1. Fuel pump
- Faulty fuel pump
Faulty gear shifting
Shifting is difficult
Refer to "Clutch drags".
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 loo ...
Shift pedal does not move
Shift shaft
Improperly adjusted shift rod
Bent shift shaft
Shift drum and shift forks
Foreign object in a shift drum groove
Seized shift fork
Bent shift fork guide bar
Transmission ...
Other materials:
Checking and adjusting the steering head
1. Stand the vehicle on a level surface
WARNINGSecurely support the vehicle so that there
is
no danger of it falling over.
NOTE:
Place the vehicle on a suitable stand so that the
front wheel is elevated.
2. Check:
Steering head
Grasp the bottom of the front fork legs an ...
Identification numbers
Record the key identification number,
vehicle identification number and model
label information in the spaces provided
below for assistance when
ordering spare parts from a Yamaha
dealer or for reference in case the vehicle
is stolen.
KEY IDENTIFICATION NUMBER:
VEHICLE IDENTIFICATION ...
Checking the steering
Worn or loose steering bearings may
cause danger. Therefore, the operation
of the steering must be checked as follows
at the intervals specified in the periodic
maintenance and lubrication
chart.
Place a stand under the engine to
raise the front wheel off the
ground. WARNING! To ...