WorksheetsSmall Engines -Final Exam
Total questions: 100
Worksheet time: 50mins
There is no oil filter on a four stroke engine so tiny particles circulate with oil. How often should the oil be changed?
every year
every 5 hours of engine operation
every 25 hours of engine operation
every 40 hours of engine operation
During the Compression stroke the piston moves________
Where is the most common spot to find the model number on small engines?
on the valve head cover
on the flywheel
on the crankcase base
on the fuel tank
Three methods of heat transfer are
conduction, potential, radiation
potential, kinetic, convection
conduction, kinetic, convection
conduction, convection, radiation
What are the three main engines systems
Ignition, Compression, Fuel
Intake, Compression, Exhaust
Intake, Fuel, Compression
Spark, Fuel, Compression
The connecting rod connects what two engine parts together?
Piston and Camshaft
Piston and Crankcase
Piston and Flywheel
Piston and Crankshaft
What are the egg-shaped pieces on the camshaft called?
Cam Lobs
Cam Valves
Cam retainers
Cam tappets
During which stroke does the spark plug fire and cause combustion in the cylinder?
Intake
Compression
Power
Exhaust
What is the purpose of the compression ring?
provide a seal between the piston and crankshaft
provide a seal between the piston and the cylinder
provide a seal between the cylinder and the crankshaft
provides a seal between crankshaft and crankcase
Which of the following is a function of a small engine?
To change heat energy into mechanical energy
To change kinetic energy into potential energy
To change rotary motion into vertical motion
To change reciprocal motion into circular motion
What are the purpose of the cam lobes?
to prevent oil in the cylinder
to move the valves open and closed
decroative
to seal the air-fuel mixture during compression
What allows gas to come into the throat of the carburetor from the fuel bowl?
Bernoulli's Principle
the Venturi effect
Induction Theory
Four-Stroke Theory
What does the idle circuit do?
allows a little fuel/air mixture to bypass the throttle plate to maintain the engine
to mix the gas and air together
makes gas come up to the carburetor from the fuel bowl
Creates a vacuum in the combustion chamber
What are the two systems for cooling an engine?
Liquid and air cooling systems
jet propulsion and injection systems
oil and vinegar cooling systems
chemical and physical systems
What is torque?
a rotating force
Pressure per square in
rotations per minute
a pulling force
Which engine type requires oil to be mixed into gas
Single cylinder
Two stroke engines
Four Stroke Engines
Auto engines
What is the number one shop safety rule?
Report all accidents to the instructor
Always wear safety glasses
No horseplaying
Know where the fire extinguishers are located
What is this ?
exhaust gasket
Sump gasket
Carburetor gasket
Head gasket
If your engine is running rich, this means?
There is more air than gas in the air/fuel mixture
There is more gas in the air in the air/fuel mixture
That the choke is closed
That the smoke coming from the engine is white
What danger does running an engine inside the shop present that requires students to open a window?
Carbon monoxide poisoning
bruising from a falling engine
a gas explosion
slipping on an oil spill
Why does the flywheel have to be so heavy?
It helps provide inertia to keep the engine going
engines are sold by the pound
it helps slow the engine to a stop
magnets are heavy and the flywheel has 1 or more
What would happen if all the piston rings were aligned?
oil would get into the combustion chamber and blue smoke would appear in the exhaust
the engine would die
nothing
the engine will run smoothly
What does the idle spring do?
Keeps tension on the governor to maintain a consistent rpms at idle
nothing, its idle after all
Increases the gas when the engine is under heavy load
Decreases the gas when the engine is under heavy load
What does the governor control?
the rpms of an engine (tries to make them constant)
the choke (controls the air going into the carburetor)
The electrical current going to the spark plug
the amount of oil in the crankcase
The governor connecting rod and spring connected to what?
the throttle plate
the choke plate
the ignition amature
the oil slinger
What role does the flywheel play in the ignition system?
Provides the magnet to complete the induction theory cycle
provides the electrical current to complete the induction theory cycle
the electrical conductor to complete the induction theory cycle
it doesn't
There are __________________ rings on a small engine piston.
one
two
three
four
A lawn mower typically will have a __________________ crankshaft.
vertical
diagonal
horizontal
flat
Reducing wear between moving parts is a function of the ____________________________.
fuel system
starting system
cooling system
lubrication system
The typical cooling system on a small engine uses _____________ to transfer heat.
fins
channels
fans
vacuum
If 1 HP equals 550 lb-ft/sec. what will 2 HP equal in 5 Minutes?
550 x 2 x 5 =
5500 lb-ft/sec
550/2 x 5 =
55 lb-ft/sec
2(550 x 300) =
330000 lb-ft/sec
(550/2) x 300 =
82500 lb-ft/sec
What is the name type of the top ring on a Piston?
Wiper ring
Compression ring
Oil ring
Combustion ring
What is the name type of the bottom ring on a Piston?
Wiper ring
Compression ring
Oil ring
Combustion ring
What is the name type of the middle ring on a Piston?
Wiper ring
Compression ring
Oil ring
Combustion ring
What is the most common type of governor system?
Electrical
Mechanical
Vacuum
Spring loaded
What is this part
Governor and oil slinger
Oil slinger
governor
came shaft
What are the three sections of the Model number?
Model, Type, Code
Serial number, sales number, date
Make, Model, Decal
the model number has just one part
What does the Code section of the model number refer to?
Year, mouth, date the engine was made and the factory and assembly line that created it
the orientation of the crankshaft
the serial number
the size of the piston
Why do valves rotate as they open and close?
to clean off the carbon build up
to provide extra torque to the engine
to assist in bringing in fresh air
the springs naturally do this
Why is gasoline not really the best fuel?
It has a low octane and high knocking index rating
it is cut with ethanol and lead
It has a high octane and low knocking index rating
it doesn't combust unless a lot of pressure is applied
Why do we have a choke on our engines before we start them?
Engines need a little more gas than air to get started, once starting you can increase air
Engines need a lot of air to get started
to ensure we flood the engine every time
To mix up the gas and oil
What are the three kinds of governors?
What is inside the ignition amature?
two copper coils
a computer chip
an electrical resistor
a magnet
What’s the difference between an oil flinger and an oil dipper?
oil flingers spin, typically on the governor gear, oil are typically found on the connecting rod
nothing
one is for small engines, the other for large
oil flingers are less effective than oil dippers
What is required at all times to go into the shop?
safety classes
a positive mental attitude
gloves
a smock
An action in which a force applied to an object and causes a displacement of the object
Power
Work
Force
All of the Above
An influence that tends to change the motion of an object or causes stress in a stationary object
Power
Work
Force
All of the Above
Which of the following is a common causes of compression loss.
Loose Spark plug
Blown head gasket
Bad valve seat
All of the above
What are the fundamental steps for troubleshooting an engine in order?
engine is getting fuel, engine is getting air, check for spark & check for compression
check for compression, engine is getting fuel, check for spark & engine is getting air
check for compression, engine is getting fuel, engine is getting air & check for spark
engine is getting fuel, check for compression, check for spark & engine is getting air
Why is it important to keep engines free of dirt and debris?
Build up of dirt and debris will act as an insulator and cause the engine to over heat.
Build up of dirt and debris can cause the engine run rich
Build up of dirt and debris can cause the engine run lean
Build up of dirt and debrise can cause the engine to give off white smoke
What can be added to help reduce the deterioration of fuel, allowing it to be stored for longer periods of time.
Ethanol
Carburetor cleaner
Stabilizer
E85
What will happen to your engine if there is too little oil?
The engine will seize
The engine may over heat
Causes wear on the internal parts of the engine
All of the above
What is the last stroke of an engine?
Exhaust
Power
Compression
Intake
What are the two valves called?
Exhaust, Intake
Intake, Outtake
Ignition, Exhaust
Up, Down
In one cycle of an engine how many times does the crankshaft rotate?
2
1
4
none
How does the electrical system provide a spark without a battery?
Induction theory: the spark is created when a magnet passes the ignition amiture
Bernoulli's Principle, the spark is sucked up by fluid dynamics
The Venturi effect creates a spark
it does have a battery
What allows gas to come into the throat of the carburetor from the fuel bowl?
Bernoulli's Principle
the Venturi effect
Induction Theory
Four-Stroke Theory
This system changes reciprocating motion into rotary motion.
Lubrication
Mechanical
Ignition
Starting
Where the piston moves up and down.
Cylinder
Crankcase
Combustion Chamber
Head
The piston is attached to the crankshaft by the:
rings
wrist pin
camshaft
connecting rod
Does the spark plug fire with each rotation of the crankshaft?
yes
no
No answer text provided.
No answer text provided.
What kind of fire is a Class C fire?
Electrical Fires
Combustible Metal fires
Regular fires
Combustible Liquids Fires
There is no oil filter on a four stroke engine so tiny particles circulate with oil. How often should the oil be changed?
every year
every 5 hours of engine operation
every 25 hours of engine operation
every 40 hours of engine operation
Name the four strokes of the 4 cycle engine in order.
(a)
______ is the international unit of frequency equal to one cycle per second.
Milliamp
Micron
Hertz
Henry
Voltage causes electrons to move in a circuit.
True
False
Small engines convert______ from the combustion of a fuel into mechanical energy.
compressed air
heat energy
DEF
kinetic energy
Which of the following parts below does NOT make up the piston?
Ring Grooves
Skirt
Cylinder
Connecting Rod
Where does compression take place in the small engine?
Piston
Cylinder
Crankcase
Flywheel
During which stroke is a partial vacuum created that sucks the air-fuel mixture into the cylinder?
Intake
Compression
Power
Exhaust
During which stroke does the spark plug fire and cause combustion in the cylinder?
Intake
Compression
Power
Exhaust
Which of the following is a function of a small engine?
To change heat energy into mechanical energy
To change kinetic energy into potential energy
To change rotary motion into vertical motion
To change reciprocal motion into circular motion
When diagnosing why an engine will not remain started, which area below is not one of the three areas that should be checked first are?
Fuel
Compression
Spark
Cutting Blade
Which of the following is NOT a function or purpose of the crankshaft?
changes motion from reciprocating to rotary
provides air flow to the engine
uses counter weights for balance to maintain rotary motion
main shaft in engine
