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:
Throttle position sensor
1. Check:
Throttle position sensor
a. Connect the digital circuit tester to the terminals
of the throttle body sensor assembly
coupler as shown.
Positive tester probe →
gray/red terminal "1"
Negative tester probe →
gray/black terminal "2"
b. Measure the throttle pos ...
Cleaning the air filter element
NOTE:
There is a check hose "1" at the bottom of the air
filter case. If dust and/or water collects in this
hose, clean the air filter element and air filter
case.
1. Remove:
Rider seat
Refer to "GENERAL CHASSIS" on page 4-1.
2. Remove:
Fuel tank
Refer to "FUEL TANK" on page ...
Care
While the open design of a motorcycle
reveals the attractiveness of the technology,
it also makes it more vulnerable.
Rust and corrosion can develop
even if high-quality components are
used. A rusty exhaust pipe may go unnoticed
on a car, however, it detracts
from the overall appearanc ...