Small Engines Chapter 9
During normal engine operation, the air-fuel mixture is typically a ratio of _____ part(s) of air to _____ part(s) of fuel.
15 to 1
What is the purpose of the carburetor float?
Maintain a constant level of fuel in the float bowl.
Vacuum carburetors _____.
are always mounted on top of the fuel tank
As soon as the intake valve opens or the intake port is uncovered in a gas engine, _____ forces air through the carburetor and manifold to fill that vacuum.
atmospheric pressure
The carburetor _____ is a round disc mounted on a shaft located at the intake end of the carburetor
choke
A(n) ______ carburetor can provide larger volumes of fuel for high-speed and high-power output.
downdraft
A wet bulb primer _____.
draws fuel from the fuel tank and pumps it into the air horn
An air-vane governor is operated by the stream of air created by cooling fins on the _____.
flywheel
A carburetor's primary function is to mix proper proportions of _____ and _____ to operate the engine.
fuel and air
A dry bulb primer _____.
increases the air pressure in the float bowl to force fuel into the main nozzle
As fuel is used from the float bowl, the float lowers and unseats a(n) _____ valve which lets fuel enter the bowl.
needle
When closed, the choke provides the _____ (leaner, richer) air-fuel mixture needed during the starting of a cold engine.
richer
Air velocity must be highest in the _____ carburetor.
updraft
In a two-cycle engine with a diaphragm-type carburetor, the fuel is drawn into the crankcase during the _____ of the piston.
upstroke
In order for the engine to operate, the carburetor must _____.
vaporize the gasoline
A(n) _____ in the float bowl is used to equalize the air pressure above the fuel in the float bowl and the air pressure entering the carburetor.
vent