Small engines

Restricts airflow into the carburetor to enrich the air-fuel mixture.

Choke system

Delivers fuel into the Venturi when the engine is operating at speeds above idle.

Main discharge nozzle

A diaphragm carburetor_____.

A. Has an interval impulse fuel pump

The purpose of the carburetor float is to____.

A. Maintain a constant fuel level in the float bowl

A(n) _____ well is a reservoir containing extra fuel that is drawn into the airstream when the throttle valve is suddenly opened.

Acceleration

Aw engine load decreases and engine speed increases, a governor will____.

B. Close the throttle

_____ primers increase air pressure in the float bowl, forcing due up the main nozzle.

B. Dry bulb

In an EFI system, the MAP sensor sends information about____ to the ECU.

B. Intake airflow and load

The IAT sensor improves the efficiency of a fuel injection system because it sends a signal to the ECU that allows the ECU to____.

B. Make adjustments to the fuel mixture based on air temperature

A centrifugal governor adjusts engine speed based on the____.

B. Movement of flyweights on the governor gear

What are three groups of carburetors can be categorized into based on airflow through the air horn?

B. Natural draft, updraft, and downdraft

If a float springs a leak or becomes saturated and sinks,______.

B. Too much gas will be provided to the engine

At normal engine speed under normal operating conditions, the proper air-fuel mixture ratio is typically____.

C. About 15 parts to 1 part fuel

Vacuum governors_____.

C. Are located between the carburetor and intake manifold.

A vacuum carburetor _____.

C. Is always mounted on top of the fuel tank

When the throttle valve is completely closed in a natural draft carburetor, most fuel is provided to the engine through the_____.

C. Primary idle orifice

The purpose of a choke is to ____ for cold engine starting l.

C. Provide a rich mixture

An O2 sensor____.

D. All of the above

The pressure reduction in the carburetor_____.

D. All of the above

A carburetor relies on pressure ______ to mix fuel and air keep the mixture moving in the right direction

Differences

An engine can have a governor or manual speed controls l, but not both.

False

An open-loop EFI system makes continuous adjustments to the fuel trump based on the level of oxygen in the exhaust gases.

False

Atmospheric pressure increases as altitude increases.

False

Some fuel-injected small engines have a gravity-fed fuel system.

False

Updraft carburetors have larger passages than downdraft carburetors.

False

A governor malfunction that results in engine speed oscillations is known as ______.

Hunting

The carburetor Venturi_____.

Increases the speed of airflow and decreases the pressure.

An economizer circuit reduces pressure in the carburetor float bowl during part-throttle operation.

True

In the fuel Injection systems used in small engines, the fuel injector is located in the throttle body.

True

The purpose of a carburetor float is to regulate fuel flow into the carburetor.

True