10 exam-style questions with answers and explanations, straight from our 1,030-question bank. Tap an answer to check yourself. When you're ready, take the scored version in the free practice test.
The PSET exam has 100 questions and runs 2 hours.
These 10 free PSET questions are organized by exam domain, so you can see how each part of the Principles of Small Engine Technology blueprint is tested. Reveal the answer and explanation under each question.
A warmed-up, carbureted generator engine repeatedly rises and falls in speed. Its governor linkage moves freely, and the correct spring is installed. Partially closing the choke steadies the engine; opening it fully brings the surging back. This response most strongly supports:
Correct answer: C - An excessively lean fuel-air mixture.
The piston of a four-stroke engine is moving upward after the intake valve has closed. Both valves are seated, and ignition has not yet occurred. Which stroke is underway?
Correct answer: A - Compression
A magneto engine's plug lead is connected to a grounded spark tester, not the spark plug. No spark appears with the stop switch in RUN. Disconnecting the stop lead at the ignition module restores spark at the same cranking speed. Where is the fault most strongly indicated?
Correct answer: B - The stop circuit is grounding the ignition module in RUN.
An engine that did not smoke before an oil change now produces blue exhaust smoke. With the engine stopped and level, a check using the specified procedure shows oil well above FULL. The oil has no gasoline odor and is the specified grade. What is the justified first correction?
Correct answer: A - Drain to the specified oil level and reassess operation.
Spark timing is correct, but an overheated spark-plug tip ignites the cylinder charge before the scheduled spark occurs. The abnormal combustion is called:
Correct answer: A - Pre-ignition
A slow-cranking engine has a known-good battery and starter current within the specified test range. During cranking, voltage drop is 1.4 V from battery positive to the starter supply terminal and 0.08 V from the starter housing to battery negative. The maximum allowed across either path is 0.50 V. Which path needs attention?
Correct answer: A - The positive-side high-current supply path.
During a generator test in a garage with its door open, two workers develop headaches and dizziness. No one smells gasoline. What must take priority?
Correct answer: D - Get everyone outside to fresh air and call emergency services.
Before removing an unfamiliar carburetor, a technician notices several possible governor-spring attachment holes. The intact spring and linkage have not yet been disturbed. Which record will best prevent a speed-control error at reassembly?
Correct answer: C - A photograph identifying both spring attachment points and the linkage route.
A rebuilt overhead-valve engine is cold, with the crankshaft in the specified valve-adjustment position. Intake clearance must be 0.10-0.15 mm; exhaust clearance must be 0.15-0.20 mm. Measurements are 0.08 mm at the intake and 0.18 mm at the exhaust. Which adjustment is required?
Correct answer: B - Increase the intake clearance; leave the exhaust clearance unchanged.
A cylinder may be reused as-is only if its bore diameter is no greater than 68.100 mm and its out-of-round is no greater than 0.050 mm. At the same inspection depth, two perpendicular bore readings are 68.080 mm and 68.010 mm. Which assessment correctly applies these limits?
Correct answer: D - Do not reuse as-is; out-of-round is 0.070 mm.
The full bank has 1,020 more PSET questions with explanations.
Continue in the free practice test →
View plans