Yamaha YZF-R125 Service Manual: Checking the lean angle sensor
1. Remove:
- Lean angle sensor
2. Check:
Lean angle sensor output voltage
Out of specification 
Replace.
a. Connect the lean angle sensor to the wire harness.
b. Connect the pocket tester (DC 20 V) to the
lean angle sensor coupler as shown.
Positive tester probe 
yellow/green "1"
Negative tester probe 
gray/black "2"
c. Set the main switch to "ON".
d. Tilt the lean angle sensor to 65.
e. Measure the lean angle sensor output voltage.
Checking the crankshaft position sensor
1. Disconnect:
Crankshaft position sensor coupler
(from the wire harness)
2. Check:
Crankshaft position sensor resistance
Out of specification Replace
the crankshaft
position senso ...
Checking the starter motor operation
1. Check:
Starter motor operation
Does not operate → Perform the electric
starting system troubleshooting, starting with
step 4.
Refer to "TROUBLESHOOTING" on page
8-9.
a. Con ...
Other materials:
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 handling the
coolant
temperature sensor. Replace any part that
was dropped or subjected to ...
Checking the drive chain
1. Measure:
15-link section "a" of the drive chain
Out of specification Replace the drive
chain.
a. Measure the length "a" between the inner
sides of the pins and the length "b" between
the outer sides of the pins on a 15-link section
of the drive chain as shown in the illustration.
...
Checking the fuses
The following procedure applies to all of the fuses.
CAUTION:To avoid a short circuit, always turn the
main
switch to "OFF" when checking or replacing
a fuse.
1. Remove:
Rider seat
Refer to "GENERAL CHASSIS" on page 4-1.
2. Check:
Fuse
a. Connect the pocket te ...