Yamaha YZF-R125 Service Manual: Troubleshooting
- General information
- Starting failures
- Incorrect engine idling speed
- Poor medium-and-high-speed performance
- Shift pedal does not move
- Jumps out of gear
- Faulty clutch
- Overheating
- Poor braking performance
- Faulty front fork legs
- Unstable handling
- Faulty lighting or signaling system
Checking the fid (fast idle solenoid)
1. Disconnect:
FID (fast idle solenoid) coupler
2. Check:
FID (fast idle solenoid) resistance
a. Disconnect the FID (fast idle solenoid) coupler
from the FID.
b. Connect the pocket t ...
General information
NOTE:
The following guide for troubleshooting does not
cover all the possible causes of trouble. It should
be helpful, however, as a guide to basic troubleshooting.
Refer to the relative procedu ...
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 ...
Removing the valves
The following procedure applies to all of the
valves and related components.
NOTE:
Before removing the internal parts of the cylinder
head (e.g., valves, valve springs, valve seats),
make sure the valves properly seal.
1. Check:
Valve sealing
Leakage at the valve seat Check
the valve
...
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.
CAUTION:Make sure the cylinder head
breather hose is
routed correctly.
...