Yamaha MBK MW125 2014, Service Manual

Page: 361 / 380

ELECTRICAL COMPONENTS
8-64
c. Measure the primary coil resistance.
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2. Check:
• Secondary coil resistance
Out of specification
→
Replace.
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a. Connect the pocket tester (
Ω ×
1k) to the ig-
nition coil as shown.
b. Measure the secondary coil resistance.
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EAS30556
CHECKING THE IGNITION SPARK GAP
1. Check:
• Ignition spark gap
Out of specification
→
Perform the ignition
system troubleshooting, starting with step 5.
Refer to “TROUBLESHOOTING” on page
8-3.
TIP
If the ignition spark gap is within specification,
the ignition system circuit is operating normally.
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a. Remove the ignition coil from the spark plug.
b. Connect the ignition checker “1” as shown.
c. Turn the main switch to “ON”.
d. Measure the ignition spark gap “a”.
e. Crank the engine by pushing the “
” of the
start switch and gradually increase the spark
gap until a misfire occurs.
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EAS30560
CHECKING THE CRANKSHAFT POSITION
SENSOR
1. Disconnect:
• Crankshaft position sensor coupler
(from the wire harness)
2. Check:
• Crankshaft position sensor resistance
Out of specification
→
Replace the crank-
shaft position sensor.
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a. Connect the pocket tester (
Ω ×
100) to the
crankshaft position sensor coupler as shown.
Secondary coil resistance
8.64–12.96 k
Ω
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
• Positive tester probe
→
red/white “1”
• Negative tester probe
→
High tension cord “2”
2
1
2
1
Minimum ignition spark gap
6.0 mm (0.24 in)
Ignition checker
90890-06754
Oppama pet–4000 spark checker
YM-34487
2. Ignition coil
Crankshaft position sensor resis-
tance
228–342
Ω
(W/L-W/R)