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:
Chain drive
Removing the drive chain
1. Stand the vehicle on a level surface.
WARNINGSecurely support the vehicle so that there
is
no danger of it falling over.
NOTE:
Place the vehicle on a suitable stand so that the
rear wheel is elevated. ...
Checking the valve seats
The following procedure applies to all of the
valves and valve seats.
1. Eliminate:
Carbon deposits
(from the valve face and valve seat)
2. Check:
Valve seat
Pitting/wear Replace the
cylinder head.
3. Measure:
Valve seat width C "a"
Out of specification Replace
the ...
Troubleshooting
Although Yamaha motorcycles receive
a thorough inspection before shipment
from the factory, trouble may occur during
operation. Any problem in the fuel,
compression, or ignition systems, for
example, can cause poor starting and
loss of power.
The following troubleshooting charts
repre ...