Yamaha YZF-R125 Service Manual: Checking the ignition coil

Yamaha YZF-R125 Service Manual / Electrical system / Electrical components / 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"

Checking the ignition coil

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"

Checking the ignition coil

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 friction plates
The following procedure applies to all of the friction plates. 1. Check: Friction plate Damage/wear Replace the friction plates as a set. 2. Measure: Friction plate thickness Out of specification Replace the friction plates as a set. NOTE: Measure the friction plate ...

Checking the fuel pressure
1. Check: Pressure regulator operation a. Remove the fuel hose connector cover "1" and disconnect the fuel hose "2" from the fuel pump. CAUTION:Although the fuel has been removed from the fuel tank, be careful when removing the fuel hose, since there may be fuel remaining i ...

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 ...