Yamaha WR450F(S) Owner's Service Manual page 656

2
1
R W
1
Sb L/W
Ω×1
– +
2
IGNITION SYSTEM
3. Inspect:
Secondary coil resistance
G
Out of specification → Replace.
Tester (+) lead → Orange lead 1
Tester (–) lead → Spark plug terminal 2
Secondary coil
resistance
4.6 ~ 6.8 kΩ at
20 ˚C (68 ˚F)
4. Inspect:
Sealed portion of ignition coil a
G
Spark plug terminal pin b
G
Threaded portion of spark plug c
G
Wear → Replace.
AC MAGNETO INSPECTION
1. Inspect:
Pick-up coil resistance
G
Out of specification → Replace.
Tester (+) lead → Red lead 1
Tester (–) lead → White lead 2
Pick-up coil
resistance
248 ~ 372 Ω at
20 ˚C (68 ˚F)
NEUTRAL SWITCH INSPECTION
1. Inspect:
Neutral switch conduct
G
Tester (+) lead → Sky blue lead 1
Tester (–) lead → Ground 2
NEUTRAL
IN GEAR
No continuity while in neutral → Replace.
Continuity while in gear → Replace.
EC628000
CDI UNIT INSPECTION
Check all electrical components. If no fault is
found, replace the CDI unit. Then check the
electrical components again.
6 - 6
–
ELEC
Tester selector
position
kΩ × 1
Tester selector
position
Ω × 100
Tester selec-
Sb
Ground
tor position
1
Ω × 1
+