Yamaha YP400T, YP400V, YP400W Service Manual page 342

EAS00746
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
Negative tester probe → orange
• Measure the primary coil resistance.
Primary coil resistance
2.16 ~ 2.64 Ω at 20 °C (68 °F)
• Connect the pocket tester (Ω × 1k) to the
ignition coil as shown.
Negative tester probe → spark plug lead 1
Positive tester probe → red/black 2
• Measure the secondary coil resistance.
Secondary coil resistance
8.64 ~ 12.96 kΩ at 20 °C (68 °F)
• Is the ignition coil OK?
YES
NO
Replace the ignition
coil.
IGNITION SYSTEM
EAS00748
7. Crankshaft position sensor resistance
• Disconnect the crankshaft position sensor
coupler from the wire harness.
• Connect the pocket tester (Ω × 100) to the
crankshaft position sensor coupler as
shown.
Positive tester probe → red 1
Negative tester probe → white 2
• Measure the crankshaft position sensor
resistance.
Crankshaft position sensor resis-
tance
248 ~ 372 Ω at 20 °C (68 °F)
(between red and white)
• Is the crankshaft position sensor OK?
EAS00749
8. Main switch
• Check the main switch for continuity.
Refer to "CHECKING THE SWITCHES".
• Is the main switch OK?
8 - 11
ELEC
1 2
R W
YES
Replace crankshaft
position sensor/stator
assembly.
YES
Replace the
switch.
– +
NO
NO
main