Carburetor Fuel Systems

Gasoline is derived from crude oil or petroleum and is made up of hydrogen and:

carbon.

oxygen.

nitrogen.

ethane.

Correct! Wrong!

An average mixture of air to gasoline for a moderate cruising speed is approximately:

8:1

10:1

15:1

25:1

Correct! Wrong!

An average mixture in the question above, of air to gasoline for a moderate cruising speed is based on:

volume of atmosphere to gasoline.

weight of atmosphere to gasoline.

parts per million (PPM)

ambient air pressure.

Correct! Wrong!

The charcoal canister in the emissions system is used to reduce the amount of __________ that is released to the atmosphere.

nitrous oxide (NOx).

carbon monoxide (CO).

carbon dioxide (CO2).

hydro-carbons (HC).

Correct! Wrong!

The maximum amount of pressure the fuel pump exerts on the fuel line to the carburetor depends on the:

strength of the diaphragm or plunger spring.

length of rocker arm.

lift of the camshaft eccentric.

number of strokes per minute.

Correct! Wrong!

The advantage of an electric fuel pump over a manual pump is that the electric fuel pump can:

be mounted in a location to push the fuel rather than suck it.

fill the carburetor bowl without having to crank the engine.

may be mounted away from the heat of the engine.

all of the above.

Correct! Wrong!

The device that controls fuel entry into a carburetor by adjusting a needle position relative to its seat in a fuel bowl is known as a (n):

metering rod.

float.

air bleed.

main discharged tube.

Correct! Wrong!

The main discharge tube runs from the ___ through the metering jets, to the air intake above the carburetor venturi.

fuel pump.

intake manifold.

float bowl.

air horn.

Correct! Wrong!

A carburetor has a(n) ____________ circuit, which is needed to provide a rich mixture for cold starting:

metering rod.

choke.

power valve.

economizer.

Correct! Wrong!

The carburetor''s low speed circuit functions when the vehicle is at low speed and:

partial throttle.

full throttle.

no throttle.

all of the above.

Correct! Wrong!

The main jets and metering rods controls the amount of fuel that is metered into the ___ in the air horn and carburetor''s venturi:

float bowl.

charcoal canister.

accelerator pump.

discharge tube.

Correct! Wrong!

The item used to prevent a "flat spot" or "hesitation" and inject more fuel when the throttle is snapped to the full open position is known as a (n):

booster venturi.

metering rod.

power valve.

accelerator pump.

Correct! Wrong!

Some carburetors incorporate a slot-shaped opening just above the idle screw port, this opening is referred to as the:

fast idle port.

off-idle circuit.

low speed circuit.

all of the above.

Correct! Wrong!

In an accelerator pump what controls the speed of the piston movement?

spring action.

direct mechanical linkage.

manifold vacuum only.

engine RPM.

Correct! Wrong!

Technician A says that a thermostatic (bimetallic) spring is used in a manual choke system. Technician B says that a choke stove in the intake manifold is sometimes used to heat the thermostatic spring. Who is correct?

Technician A.

Technician B.

both A and B.

neither A nor B.

Correct! Wrong!

To increase the RPM of the engine when cold, a(n) ____________ is used to keep the throttle partially open when the choke is activated:

fast idle cam.

choke unloader.

idle mixture screw.

window scraper.

Correct! Wrong!

There are three types of vacuum created by an engine and carburetor: 1/ in the intake manifold below the throttle plates, and 2/ in the carburetor''s venturi, and 3/ the ported vacuum.

true.

false.

Correct! Wrong!

A loose carburetor mounting to the intake manifold may cause:

the engine to run with a lean mixture.

poor idling.

hesitation.

all of the above.

Correct! Wrong!

How many "circuits" are there in most automotive carburetors?

three.

five.

seven.

nine.

Correct! Wrong!

When a carburetor throttle butterfly valves move toward the full throttle position, what is increasing the fuel to supply more power as required?

metering rods.

accelerator pump.

check ball.

throttle plate.

Correct! Wrong!

What is the purpose of a venturi in a carburetor?

increase air volume.

creates a low pressure area.

reduces low restriction.

aids in the starting of a vehicle.

Correct! Wrong!

In a carburetor, a low float level would result in:

a leaner mixture.

better fuel economy at the expense of power.

a rich mixture.

engine overheating.

Correct! Wrong!

A carburetor is assisted in preventing throttle plate icing and to help atomize fuel in cold weather start-ups with:

heat riser valve.

economizer valve.

choke valve.

dash pot.

Correct! Wrong!

What is the function of the automatic choke?

to limit the amount of air entering the engine.

to provide blowby vapor for the PCV system.

to provide the best possible engine performance in cold weather.

to add raw fuel to the engine during warm-up.

Correct! Wrong!

If the technician is not familiar with removing a particular carburetor, which of the following should be done first?

disconnect the fuel supply line and start the engine to empty the float bowl.

use heat to help loosen any bolts that are rusted in place.

label all the connections so that reassembly will not be confusing.

ask another technician for advice.

Correct! Wrong!

Carburetor Fuel Systems

Gasoline is derived from crude oil or petroleum and is made up of hydrogen and:

An average mixture of air to gasoline for a moderate cruising speed is approximately:

An average mixture in the question above, of air to gasoline for a moderate cruising speed is based on:

The charcoal canister in the emissions system is used to reduce the amount of __________ that is released to the atmosphere.

The maximum amount of pressure the fuel pump exerts on the fuel line to the carburetor depends on the:

The advantage of an electric fuel pump over a manual pump is that the electric fuel pump can:

The device that controls fuel entry into a carburetor by adjusting a needle position relative to its seat in a fuel bowl is known as a (n):

The main discharge tube runs from the ___ through the metering jets, to the air intake above the carburetor venturi.

A carburetor has a(n) ____________ circuit, which is needed to provide a rich mixture for cold starting:

The carburetor''s low speed circuit functions when the vehicle is at low speed and:

The main jets and metering rods controls the amount of fuel that is metered into the ___ in the air horn and carburetor''s venturi:

The item used to prevent a "flat spot" or "hesitation" and inject more fuel when the throttle is snapped to the full open position is known as a (n):

Some carburetors incorporate a slot-shaped opening just above the idle screw port, this opening is referred to as the:

In an accelerator pump what controls the speed of the piston movement?

Technician A says that a thermostatic (bimetallic) spring is used in a manual choke system. Technician B says that a choke stove in the intake manifold is sometimes used to heat the thermostatic spring. Who is correct?

To increase the RPM of the engine when cold, a(n) ____________ is used to keep the throttle partially open when the choke is activated:

There are three types of vacuum created by an engine and carburetor: 1/ in the intake manifold below the throttle plates, and 2/ in the carburetor''s venturi, and 3/ the ported vacuum.

A loose carburetor mounting to the intake manifold may cause:

How many "circuits" are there in most automotive carburetors?

When a carburetor throttle butterfly valves move toward the full throttle position, what is increasing the fuel to supply more power as required?

What is the purpose of a venturi in a carburetor?

In a carburetor, a low float level would result in:

A carburetor is assisted in preventing throttle plate icing and to help atomize fuel in cold weather start-ups with:

What is the function of the automatic choke?

If the technician is not familiar with removing a particular carburetor, which of the following should be done first?

Success!

Heavy-Duty Mechanic - Trucks & Equipment

Gasoline is derived from crude oil or petroleum and is made up of hydrogen and:

An average mixture of air to gasoline for a moderate cruising speed is approximately:

An average mixture in the question above, of air to gasoline for a moderate cruising speed is based on:

The charcoal canister in the emissions system is used to reduce the amount of __________ that is released to the atmosphere.

The maximum amount of pressure the fuel pump exerts on the fuel line to the carburetor depends on the:

The advantage of an electric fuel pump over a manual pump is that the electric fuel pump can:

The device that controls fuel entry into a carburetor by adjusting a needle position relative to its seat in a fuel bowl is known as a (n):

The main discharge tube runs from the ________ ___________ through the metering jets, to the air intake above the carburetor venturi.

A carburetor has a(n) ____________ circuit, which is needed to provide a rich mixture for cold starting:

The carburetor''s low speed circuit functions when the vehicle is at low speed and:

The main jets and metering rods controls the amount of fuel that is metered into the ________ ___________ in the air horn and carburetor''s venturi:

The item used to prevent a "flat spot" or "hesitation" and inject more fuel when the throttle is snapped to the full open position is known as a (n):

Some carburetors incorporate a slot-shaped opening just above the idle screw port, this opening is referred to as the:

In an accelerator pump what controls the speed of the piston movement?

Technician A says that a thermostatic (bimetallic) spring is used in a manual choke system. Technician B says that a choke stove in the intake manifold is sometimes used to heat the thermostatic spring. Who is correct?

To increase the RPM of the engine when cold, a(n) ____________ is used to keep the throttle partially open when the choke is activated:

There are three types of vacuum created by an engine and carburetor: 1/ in the intake manifold below the throttle plates, and 2/ in the carburetor''s venturi, and 3/ the ported vacuum.

A loose carburetor mounting to the intake manifold may cause:

How many "circuits" are there in most automotive carburetors?

When a carburetor throttle butterfly valves move toward the full throttle position, what is increasing the fuel to supply more power as required?

What is the purpose of a venturi in a carburetor?

In a carburetor, a low float level would result in:

A carburetor is assisted in preventing throttle plate icing and to help atomize fuel in cold weather start-ups with:

What is the function of the automatic choke?

If the technician is not familiar with removing a particular carburetor, which of the following should be done first?

Success!

Heavy-Duty Mechanic - Trucks & Equipment

The main discharge tube runs from the ___ through the metering jets, to the air intake above the carburetor venturi.

The main jets and metering rods controls the amount of fuel that is metered into the ___ in the air horn and carburetor''s venturi: