Ignition System Troubleshooting; No Spark At Plug - Honda 2003 NPS50 Ruckus Service Manual

IGNITION SYSTEM
TROUBLESHOOTIN G
Inspect the following before diagnosing the system.
•
- Faulty spark plug
- Loose spark plug cap or spark plug wire connection
- Water got into the spark plug cap (leaking the ignition coil secondary voltage)
Temporarily exchange the ignition coil with the other good one and perform the spark test. If there is spark, the
•
exchanged ignition coil is faulty.

No spark at plug

Unusual condition
Low peak voltage.
Ignition coil
primary
voltage
No peak voltage.
Peak voltage is normal, but no
spark jumps at the plug.
Ignition pulse Low peak voltage.
generator
No peak voltage.
1 7-4
Probable cause (check in numerical order)
1. Incorrect peak voltage adapter connections. (System is
normal if measured voltage is over the specifications
with reverse connections).
2. The multi meter impedance is too low; below 10 MQ/
DCV.
3. Cranking speed is too low. (Battery is undercharged.)
4. The sampling timing of the tester and measured pulse
were not synchronized (system is normal if measured
voltage is over the standard voltage at least once).
(Does not apply to Imrie tester).
5. Poorly connected connectors or an open circuit in igni-
tion system.
6. Faulty ignition coil.
7. Faulty ECM (in case when above No. 1
1. Incorrect peak voltage adapter connections. {System is
normal if measured voltage is over the specifications
with reverse connections).
2. Battery is under charged. (Voltage drops largely when
the engine is started.)
3. Short circuit in engine stop switch wire.
4. Faulty ignition switch or engine stop switch.
5. Loose or poorly connected ECM connectors.
6. Open circuit or poor connection in ground wire of the
ECM.
7. Faulty peale voltage adapter.
8. Faulty ignition pulse generator (Measure peak voltage).
9. Faulty ECM (in case when above No.1 - 8 are normal).
1. Faulty spark plug or leaking ignition coil secondary cur-
rent.
2. Faulty ignition coil.
1. The multi meter impedance is too low; below 10 MQ/
DCV.
2. Cranking speed is too slow. (Battery is undercharged.)
3. The sampling timing of the tester and measured pulse
were not synchronized (system is normal if measured
voltage is over the standard voltage at least once).
4. Faulty ignition pulse generator (in case when above
No.1 - 3 are normal).
1. Faulty peak voltage adapter or Imrie tester.
2. Faulty ignition pulse generator.
6 are normal).
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