Checking The Diode; Checking The Ignition Spark Gap; Checking The Spark Plug Cap - Yamaha WR450F Owner's Service Manual

Result
Continuity
(between "3" to "4")
EAS2GC1388

CHECKING THE DIODE

1. Check:
• Diode
Out of specification  Replace.
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
TIP
The pocket tester and the analog pocket tester
readings are shown in the following table.
No continuity
Tester positive lead  Sky blue
"1"
Tester negative lead  Green/
Black "2"
Continuity
Tester positive lead  Green/
Black "2"
Tester negative lead  Sky blue
"1"
No continuity
Tester positive lead  Red "3"
Tester negative lead  Red/Blue
"4"
Continuity
Tester positive lead  Red/Blue
"4"
Tester negative lead  Red "3"
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a. Disconnect the diode from the wire harness.
b. Connect the pocket tester (  1) to the di-
ode coupler as shown.
c. Check the diode for continuity.
d. Check the diode for no continuity.
1
Sb
G/B
2
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3
R
R/L
4
9-73
ELECTRICAL COMPONENTS

CHECKING THE IGNITION SPARK GAP

EAS2GC1389
1. Check:
• Ignition spark gap
Out of specification  Perform the ignition
system troubleshooting, starting with step 4.
Refer to "TROUBLESHOOTING" on page 9-
4.
Minimum ignition spark gap
6.0 mm (0.24 in)
TIP
If the ignition spark gap is within specification,
the ignition system circuit is operating normally.
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a. Remove the spark plug cap from the spark
plug.
b. Connect the ignition checker "1" as shown.
Ignition checker
90890-06754
Oppama pet–4000 spark checker
YM-34487
2. Spark plug cap
c. Push the engine stop switch.
d. Measure the ignition spark gap "a".
e. Crank the engine by pushing the start switch
and gradually increase the spark gap until a
misfire occurs.
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EAS2GC1390

CHECKING THE SPARK PLUG CAP

1. Remove:
• Spark plug cap
(from the spark plug lead)
2. Check:
• Spark plug cap resistance
Out of specification  Replace.
Resistance
7.50–12.50 k