Update 2025-2026 Exam 125 Questions with
100% Verified Correct Answers Guaranteed A+
1. The vibration damper on an auto engine is fastened to the - CORRECT ANSWER:
Crankshaft
10. Engine timing is generally set by using a - CORRECT ANSWER: Strobe light
11. If an engine is operating for long periods of time at part throttle opening the -
CORRECT ANSWER: Spark plugs will become covered with carbon
12. Leaking intake valve guides will cause - CORRECT ANSWER: Excessive oil
consumption
13. Flooding of a carburetor is generally caused by - CORRECT ANSWER: A stuck float
needle valve
14. On many cars the fuel pump is combined with the - CORRECT ANSWER: vacuum
pump
15. Corbon fouling of a spark plug is an indication of - CORRECT ANSWER: To rich a
mixture
16. If a test shows that generator output is excessive even after the F Terminal has
been disconnected the trouble may be traced to - CORRECT ANSWER: The generator
17. An automobile alternator converts alternating current to direct current, by means of -
CORRECT ANSWER: Silicon diodes
, 18. Hard starting is very often caused by - CORRECT ANSWER: Improper choke
operation
19. A car with a history of burned points would probably indicate - CORRECT ANSWER:
Too high setting of the voltage regulator
2. Most small gas engines use a _________ ignition system - CORRECT ANSWER:
Magneto
20. When it is necessary to recondition brake drums, the maximum allowable amount of
the oversize is__________ inches - CORRECT ANSWER: .060
21. The amount of air fuel mixture taken into the cylinder on the intake Stroke is a
measure of the engines. - CORRECT ANSWER: Volumetric efficiency
22. Welch plugs are installed on engines to provide - CORRECT ANSWER: A means of
removing the sand after the engine is cast
23. The two cycle engine produces a power stroke with every_________
Of the crankshaft. - CORRECT ANSWER: Revolution
24. Preignition may be caused by - CORRECT ANSWER: Carbon deposits
25. The size of an outdoor motor propeller is always given in - CORRECT ANSWER:
Diameter and pitch
26. Closed, crank case ventilation systems are used to - CORRECT ANSWER: Aid and
prevention of air contamination