Yamaha YFZ450S 2003 Service Manual page 335

EBS01038
5. 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 →
Negative tester probe →
• Measure the primary coil resistance.
Primary coil resistance
0.08 ~ 0.10 Ω at 20 °C (68 °F)
• Connect the pocket tester (Ω × 1k) to the
ignition coil as shown.
Negative tester probe →
Positive tester probe →
2
• Measure the secondary coil resistance.
Secondary coil resistance
4.56 ~ 6.84 kΩ at 20 °C (68 °F)
• Is the ignition coil OK?
YES
orange lead terminal 1
black lead terminal 2
1
2
black lead terminal 1
ignition coil terminal 2
1
NO
Replace the ignition
coil.
IGNITION SYSTEM
EBS01041
6. Main switch
• Check the main switch for continuity.
Refer to "CHECKING THE SWITCHES".
• Is the main switch OK?
EBS01042
7. Engine stop switch
• Check the engine stop switch for continu-
ity.
Refer to "CHECKING THE SWITCHES".
• Is the engine stop switch OK?
8. Throttle switch
• Check the throttle switch for continuity.
Refer to "CHECKING THE SWITCHES".
• Is the throttle switch OK?
9. Carburetor switch
• Check the carburetor switch for continuity.
Refer to "CHECKING THE SWITCHES".
• Is the carburetor switch OK?
8 - 12
ELEC
YES
Replace the
switch.
YES
Replace the handle-
bar switch.
YES
Replace the throttle
switch.
YES
Replace the carbure-
tor switch.
– +
NO
main
NO
NO
NO