Checking The Ignition Spark Gap; Checking The Crankshaft Position Sensor - Yamaha MBK MW125 2014 Service Manual

c. Measure the primary coil resistance.
▲ ▲▲▲ ▲ ▲▲▲ ▲ ▲ ▲▲▲ ▲
2. Check:
• Secondary coil resistance
Out of specification → Replace.
Secondary coil resistance
8.64–12.96 kΩ
▼ ▼▼▼ ▼ ▼▼▼ ▼ ▼ ▼▼▼ ▼
a. Connect the pocket tester (Ω × 1k) to the ig-
nition coil as shown.
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
• Positive tester probe →
red/white "1"
• Negative tester probe →
High tension cord "2"
b. Measure the secondary coil resistance.
▲ ▲▲▲ ▲ ▲▲▲ ▲ ▲ ▲▲▲ ▲
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.
2
1
▲ ▲▲▲ ▲ ▲ ▲▲▲ ▲ ▲ ▲▲▲ ▲
▼ ▼▼▼ ▼ ▼ ▼▼▼ ▼ ▼ ▼▼▼ ▼
1
2
▲ ▲▲▲ ▲ ▲ ▲▲▲ ▲ ▲ ▲▲▲ ▲
ELECTRICAL COMPONENTS
TIP
If the ignition spark gap is within specification,
the ignition system circuit is operating normally.
▼ ▼▼▼ ▼ ▼▼▼ ▼
a. Remove the ignition coil from the spark plug.
b. Connect the ignition checker "1" as shown.
▲▲▲
▼▼▼
2. Ignition coil
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.
▲ ▲▲▲ ▲ ▲▲▲ ▲
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.
▲▲▲
▼ ▼▼▼ ▼ ▼▼▼ ▼
a. Connect the pocket tester (Ω × 100) to the
crankshaft position sensor coupler as shown.
8-64
Minimum ignition spark gap
6.0 mm (0.24 in)
▼ ▼▼▼ ▼ ▼ ▼▼▼ ▼ ▼ ▼▼▼ ▼
Ignition checker
90890-06754
Oppama pet–4000 spark checker
YM-34487
▲ ▲▲▲ ▲ ▲ ▲▲▲ ▲ ▲ ▲▲▲ ▲
Crankshaft position sensor resis-
tance
228–342 Ω (W/L-W/R)
▼ ▼▼▼ ▼ ▼ ▼▼▼ ▼ ▼ ▼▼▼ ▼
▼ ▼▼▼ ▼ ▼▼▼
▲ ▲▲▲ ▲ ▲▲▲
▼ ▼▼▼ ▼ ▼▼▼