Yamaha YFM7FGPW Service Manual page 418

EBS01036
5. Spark plug cap resistance
• Remove the spark plug cap from the spark
plug lead.
• Connect the pocket tester (Ω × 1k) to the
spark plug cap as shown.
• Measure the spark plug cap resistance.
Spark plug cap resistance
10.0 kΩ at 20 °C (68 °F)
• Is the spark plug cap OK?
YES NO
Replace the spark
plug cap.
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IGNITION SYSTEM
EBS01038
6. Ignition coil resistance
• Disconnect the ignition coil connectors
from the ignition coil terminals.
• Connect the pocket tester (Ω × 1) to the
ignition coil as shown.
Positive tester probe →
red/black lead terminal 1
Negative tester probe →
• Measure the primary coil resistance.
Primary coil resistance
3.4 ~ 4.6 Ω at 20 °C (68 °F)
• Connect the pocket tester (Ω × 1k) to the
ignition coil as shown.
Positive tester probe →
red/black lead terminal 1
Negative tester probe → spark plug lead 2
• Measure the secondary coil resistance.
Secondary coil resistance
10.4 ~ 15.6 kΩ at 20 °C (68 °F)
• Is the ignition coil OK?
YES
– +
ELEC
orange lead terminal 2
NO
Replace the ignition
coil.