Yamaha DT125RE 2005 Service Manual page 266

EAS00744
3. Spark plug cap resistance
• Remove the spark plug cap from the spark
plug lead.
• Connect the pocket tester ("Ω x 1k" range)
to the spark plug cap as shown.
• Measure the spark plug cap resistance.
Spark plug cap resistance
5KΩ at 20°C (68 °C)
• Is the spark plug cap OK?
YES
Replace the spark
plug cap.
EAS00746
4. Ignition coil resistance (Orange) from the
wireharness
• Disconnect the ignition coil connectors
from the ignition coil terminals.
• Connect the pocket tester (Ω x 1) to the
ignition coil as shown.
Positive tester probe
Negative tester probe
base
• Measure the primary coil resistance.
Primary coil resistance
0.23 +/- 20°C (68 °C)
NO
Orange terminal
Ignition coil
8-9
IGNITION SYSTEM
• Connect the pocket tester (Ω x 1k) to the
ignition coil as shown.
Negative tester probe
Positive tester probe
• Measure the secondary coil resistance.
Secondary coil resistance
7.9 +/- kΩ 20°C (68 °C)
• Is the ignition coil OK?
YES
ELEC
Ignition coil base
spark plug lead
NO
Replace the ignition
coil.