Yamaha YZF-R125 Service Manual: Troubleshooting
NOTE:
- Before troubleshooting, remove the following part(s):
1. Rider seat
2. Fuel tank
3. Right upper side cowling
4. Passenger seat
Circuit diagram
4. Main fuse
5. Main switch
6. Radiator fan motor fuse
9. Battery
22.Coolant temperature sensor
32.Radiator fan motor relay
33.Radiator fan motor
59.Coolant temperature warning light
64.Ig ...
Other materials:
Checking the connections
Check the leads, couplers, and connectors for
stains, rust, moisture, etc.
1. Disconnect:
Lead
Coupler
Connector
2. Check:
Lead
Coupler
Connector
Moisture → Dry with an air blower.
Rust/stains → Connect and disconnect several
times.
3. Check:
All co ...
Checking the piston rings
1. Measure:
Piston ring side clearance
Out of specification Replace the
piston
and piston rings as a set.
NOTE:
Before measuring the piston ring side clearance,
eliminate any carbon deposits from the piston
ring grooves and piston rings.
2. Install:
Piston ring
(into the cylind ...
Installing the cylinder head
1. Install:
Cylinder head
NOTE:
Pass the timing chain through the timing chain
cavity.
2. Tighten:
Cylinder head bolts "1"
Cylinder head bolts "2"
NOTE:
Lubricate the cylinder head bolts and washers
with engine oil.
Tighten the cylinder head bolts in the proper
tighten ...