Checking The Spark Plug Cap - Yamaha YZ125 2009 Owner's Service Manual

2. Inspect:
• Secondary coil resistance
Out of specification → Replace.
Tester (+) lead → Spark plug lead "1"
Tester (-) lead → Yellow lead "2"
Secondary coil
resistance
5.7–8.5 kΩat 20
°C (68 °F)
• Remove the spark plug cap by turning it coun-
terclockwise and inspect.
• Install the spark plug cap by turning it clock-
wise until it is tight.

CHECKING THE SPARK PLUG CAP

1. Inspect:
• Spark plug cap
Loose connection → Tighten.
Deteriorated/damaged → Replace.
• Spark plug cap resistance
Out of specification → Replace.
Tester (+) lead → Spark plug lead terminal
"1"
Tester (-) lead → Spark plug terminal "2"
Spark plug cap
resistance
4–6 kΩ at 20 °C
(68 °F)
Tester selector
position
kΩ × 1
Tester selector
position
kΩ × 1
6-6
IGNITION SYSTEM
CHECKING THE CDI MAGNETO
1. Inspect:
• Pickup coil resistance
Out of specification → Replace.
Tester (+) lead → White/Red lead "1"
Tester (-) lead → White/Blue lead "2"
Pickup coil resis-
tance
248–372 Ω at 20
°C (68 °F)
2. Inspect:
• Charging coil 1 resistance
Out of specification → Replace.
Tester (+) lead → Black/Red lead "1"
Tester (-) lead → Green/White lead "2"
Charging coil 1
resistance
720–1,080 Ω at
20 °C (68 °F)
Tester selector
position
Ω × 100
Tester selector
position
Ω × 100