EETC - Equipment & Engine Training Council Engine Troubleshooting and Failure Questions and Answers

Question 1

A technician is diagnosing an engine that starts easily when cold but stalls after 5-10 minutes of operation.
Once it stalls, it cannot be restarted until it has cooled down for a significant period.
What is the MOST likely cause of this issue?

Accepted Answer

Faulty ignition coil

Answer

Clogged fuel filter

Answer

Worn piston rings

Answer

Incorrect valve lash

Question 2

Upon starting a four-stroke engine for a customer complaint of high oil consumption, a technician observes a consistent stream of blue-tinted smoke from the muffler. This symptom is a classic indicator of which internal engine problem?

Accepted Answer

The engine is burning oil

Answer

The engine is running rich

Answer

Coolant is leaking into the cylinder

Answer

The fuel is contaminated with water

Question 3

A two-stroke engine on a string trimmer starts and idles properly, but bogs down and loses all power as soon as the throttle is applied. The carburetor has been cleaned and fuel flow is confirmed to be good. Which of the following components should be inspected next for a potential restriction?

Accepted Answer

The spark arrestor screen

Answer

The air filter

Answer

The ignition coil

Answer

The piston rings

Question 4

A lawnmower engine abruptly stopped after the blade struck a large tree root. Now, the engine has a weak or non-existent spark, and the starter rope kicks back violently. What is the MOST likely cause of these symptoms?

Accepted Answer

The flywheel key has sheared

Answer

The impact fouled the spark plug

Answer

The carburetor float is stuck

Answer

The low-oil sensor has failed

Question 5

A technician performs a compression test on a single-cylinder engine and gets a reading of 45 PSI, which is well below the manufacturer's specification. To quickly help determine if the low compression is caused by worn piston rings or a poor valve seal, what is the immediate next diagnostic step?

Accepted Answer

Add a small amount of oil to the cylinder and re-test

Answer

Perform a cylinder leak-down test

Answer

Replace the head gasket

Answer

Check and adjust the valve lash

Question 6

A V-twin, air-cooled engine is running rough, overheating, and pushing oily smoke from the crankcase breather tube. A compression test reveals one cylinder has significantly lower compression than the other. What is the MOST likely failure?

Accepted Answer

A blown head gasket

Answer

A clogged fuel injector

Answer

A failed ignition coil on one cylinder

Answer

A sheared flywheel key