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 ...

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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 ...

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1. Check: Rectifier/regulator output voltage Out of specification → Replace the rectifier/ regulator. a. Set the engine tachometer to the spark plug lead. b. Connect the pocket tester (DC 20 V) to the rectifier/regulator coupler as shown. Positive tester probe red "1" Negat ...

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