
TP-6903 5/16a
Fuel System Troubleshooting 53
3.7. Backfire
Definition:
The fuel ignites in the intake manifold, or in
the exhaust system, making a loud popping noise.
WARNING
Risk of Fire. Can cause severe injury or death.
Do not smoke or permit flames or sparks near fuels or the
fuel system.
Servicing the air cleaner. A sudden backfire can cause
severe injury or death.
Do not operate the engine with
the air cleaner removed.
WARNING
Electrical shock can cause injury.
Do not touch wires while engine is running.
Figure 3-9 Backfire Troubleshooting
Checks Action
Preliminary Check
None.
Ignition System Checks
Check for proper ignition output voltage with a spark tester.
Check the spark plug leads by connecting an ohmmeter to the ends of each lead in
question. If the meter reads over 15,000 ohms, replace the leads.
Check the connection at ignition coil.
Check for deteriorated spark plug lead insulation.
Remove the plugs and inspect them for the following conditions:
o
Wet plugs (oil fouling).
o
Cracks.
o
Wear.
o
Improper
gap.
o
Burned
electrodes.
o
Heavy
deposits.
Engine Mechanical Check
Check the engine for the following:
o
Improper valve timing.
o
Engine
compression.
o
Manifold vacuum leaks.
o
Intake manifold gaskets.
o
Sticking or leaking valves.
o
Exhaust system leakage.
Summary of Contents for KG2204
Page 8: ...8 Safety Precautions and Instructions TP 6903 5 16a Notes ...
Page 44: ...44 Diagnostic Troubleshooting Codes TP 6903 5 16a Notes ...
Page 58: ...58 Fuel System Troubleshooting TP 6903 5 16a Notes ...
Page 100: ...100 TP 6903 Notes ...
Page 105: ...Notes ...
Page 106: ...Notes ...
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