Yamaha YFM250RX 2008 Service Manual page 278

EBS01038
6. Ignition coil resistance
• Disconnect the ignition coil coupler from the
ignition coil.
• Connect the pocket tester (Ω × 1) to the
ignition coil as shown.
Positive tester probe →
orange lead terminal
Negative tester probe →
ignition coil base
• Measure the primary coil resistance.
Primary coil resistance
0.18 ~ 0.28 Ω at 20°C (68°F)
• Connect the pocket tester (Ω × 1k) to the
ignition coil as shown.
Positive tester probe →
high tension code
Negative tester probe →
orange lead terminal
• Measure the secondary coil resistance.
Secondary coil resistance
6.32 ~ 9.48 kΩ at 20°C (68°F)
• Is the ignition coil OK?
YES
NO
Replace the ignition
coil.
7-11
IGNITION SYSTEM
EBS01041
7. Main switch
• Check the main switch for continuity.
Refer to "CHECKING THE SWITCHES".
• Is the main switch OK?
YES
EBS01042
8. Engine stop switch
• Check the engine stop switch for continuity.
Refer to "CHECKING THE SWITCHES".
• Is the engine stop switch OK?
YES
EBS01040
9. Pickup coil resistance
• Disconnect the pickup coil coupler from the
wire harness.
• Connect the pocket tester (Ω × 100) to the
pickup coil terminal as shown.
Positive tester probe → red terminal
Negative tester probe → white terminal
• Measure the pickup coil resistance.
Pickup coil resistance
248 ~ 372 Ω at 20°C (68°F)
• Is the pickup coil OK?
YES
ELEC
NO
Replace the main
switch.
NO
Replace the handle-
bar switch.
R W
( BLACK )
NO
Replace the pickup
coil/stator assembly.