Yamaha YZF-R125 Service Manual: Checking the thermostat
1. Check:
- Thermostat
Does not open at 80.5-83.5 C (176.9-182.3
F)
Replace.
a. Suspend the thermostat "1" in a container "2" filled with water.
b. Slowly heat the water "3".
c. Place a thermometer "4" in the water.
d. While stirring the water, observe the thermostat and thermometer's indicated temperature.
A. Fully closed
B. Fully open
NOTE:
If the accuracy of the thermostat is in doubt, replace it. A faulty thermostat could cause serious overheating or overcooling.
2. Check:
- Thermostat cover
Cracks/damage
Replace.
3. Check:
- Radiator inlet hose
Cracks/damage
Replace.
Thermostat
...
Installing the thermostat
1. Install:
Thermostat
NOTE:
Install the thermostat with its breather hole "a"
facing up.
2. Install:
Copper washer
Coolant temperature sensor
CAUTION:Use extreme care when ...
Other materials:
Checking the front brake caliper
1. Check:
Brake caliper pistons "1"
Rust/scratches/wear Replace the
brake
caliper assembly.
Brake caliper body "2"
Cracks/damage Replace the brake
caliper
assembly.
Brake fluid delivery passages
(brake caliper body)
Obstruction Blow out with
compressed air.
...
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 ...
Troubleshooting method
The engine operation is not normal and the
engine trouble warning light comes on.
1. Check:
Fault code number
a. Check the fault code number displayed on
the FI diagnostic tool.
b. Identify the faulty system with the fault code.
Refer to "Self-Diagnostic Function table".
c. Identi ...