Yamaha YZF-R125 Service Manual: Checking the ignition coil
1. Check:
Primary coil resistance
Out of specification
Replace.
a. Disconnect the ignition coil connectors from the ignition coil terminals.
b. Connect the pocket tester (
× 1)
to the ignition
coil as shown.
Positive tester probe
red/white "1"
Negative tester probe
orange "2"
c. Measure the primary coil resistance.
2. Check:
Secondary coil resistance
Out of specification Replace.
a. Disconnect the spark plug cap from the ignition coil.
b. Connect the pocket tester ( ×
1k) to the ignition
coil as shown.
- Positive tester probe
orange "1" - Negative tester probe
spark plug lead "2"
c. Measure the secondary coil resistance.
Checking the spark plug cap
1. Check:
Spark plug cap resistance
Out of specification Replace.
a. Remove the spark plug cap from the spark
plug lead.
b. Connect the pocket tester ( × 1k)
to the
spark plug cap as ...
Checking the ignition spark gap
1. Check:
Ignition spark gap
Out of specification Perform the
ignition
system troubleshooting, starting with step 5.
Refer to "TROUBLESHOOTING" on page
8-3.
NOTE:
If the ignition spark gap ...
Other materials:
Checking the speed sensor
1. Check:
Speed sensor output voltage
Out of specification → Replace.
a. Connect the pocket tester (DC 20 V) to the
speed sensor coupler (wire harness end) as
shown.
Positive tester probe
gray "1"
Negative tester probe
gray/black "2"
b. Set the main switch to "ON".
c. ...
Checking the rear brake caliper
1. Check:
Brake caliper piston "1"
Rust/scratches/wear Replace the
brake
caliper piston.
Brake caliper cylinder "2"
Scratches/wear Replace the
brake caliper
assembly.
Brake caliper body "3"
Cracks/damage Replace the
brake caliper
assembly.
Brake fluid deli ...
Installing the piston and cylinder
1. Install:
Top ring "1"
2nd ring "2"
Oil ring expander "3"
Lower oil ring rail "4"
Upper oil ring rail "5"
NOTE:
Be sure to install the piston rings so that the
manufacturer marks or numbers face up.
2. Install:
Piston "1"
Piston pin "2"
Piston pin clips "3"
NOTE:
...