EETC EETC - Equipment & Engine Training Council Ignition Systems and Spark Technology Questions and Answers 2

Question 1

An engine has good compression and fuel but will not start. A spark test shows a weak orange spark. What is the most likely cause?

Accepted Answer

Worn ignition coil or incorrect coil-to-flywheel air gap

Answer

A weak orange spark indicates insufficient coil output, most commonly caused by a deteriorating ignition coil or an incorrect air gap between the coil armature and flywheel magnets.

Question 2

What does the kill switch (stop switch) on a small engine do to stop the engine?

Accepted Answer

Grounds the ignition coil primary circuit to prevent spark

Answer

The kill switch grounds the ignition coil's primary winding, which prevents the voltage collapse needed to produce a spark, stopping combustion and shutting the engine down.

Question 3

What symptom suggests ignition timing is too retarded (late) on a small engine?

Accepted Answer

Engine lacks power, runs hot, and has difficulty starting

Answer

Retarded ignition timing means combustion peaks too late in the power stroke, wasting energy as heat rather than pushing the piston, resulting in power loss and overheating.

Question 4

Which spark plug heat range should be used in high-load commercial equipment engines compared to light-duty residential equipment?

Accepted Answer

Colder plug in commercial engines to prevent pre-ignition under sustained high loads

Answer

A colder heat range plug transfers heat away from the tip faster, preventing pre-ignition in commercial engines that run under sustained heavy loads with higher combustion temperatures.

Question 5

What is the purpose of the resistor built into many modern spark plugs?

Accepted Answer

Suppress radio frequency interference (RFI) from the ignition system

Answer

The resistor inside the spark plug suppresses electromagnetic interference generated by the ignition spark, protecting electronic controls and nearby radio equipment.

EETC - Equipment & Engine Training Council Practice Test

EETC - Equipment & Engine Training Council Practice Test

EETC EETC - Equipment & Engine Training Council Ignition Systems and Spark Technology Questions and Answers 2