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:
Cable routing
Front brake light switch lead
Right handlebar switch lead
Throttle cable
Main switch
Clutch cable
Clutch switch lead
Left handlebar switch lead
Sub-wire harness
Horn
Speed sensor lead
Front brake hose
Main switch lead
Left headlight assembly lead
Right headlight asse ...
Replacing the fuses
Replacing the fuses
Fuse box
Spare fuse
Headlight fuse
Signaling system fuse
Ignition fuse
Radiator fan fuse
Main fuse
The fuse box is located under the rider
seat.
If a fuse is blown, replace it as follows.
Turn the key to "OFF" and turn off
the electrical circuit i ...
Removing the throttle body
1. Extract the fuel in the fuel tank through the
fuel tank filler hole with a pump.
2. Disconnect:
Fuel hose
WARNINGCover the fuel hose connections with a
cloth
when disconnecting them. Residual pressure
in the fuel lines could cause fuel to
spurt out when removing the h ...