Figure 1 Model AA Carburetor
The carburetor developed by the
Rochester Products Division, Rochester, New York is an entirely new design
and differs from previous carburetors, as the air entrance is horizontal.
The carburetor incorporates a number of distinctly new features of
importance to the car
owner and also the service
mechanic.
Foremost of the major advantages
of the new carburetor is the comparative low gasoline bowl temperatures
during all driving conditions. This marks a definite stride forward in
reducing vapor lock, and the minimizing of hot starting complaints. The
gasoline temperatures in the carburetor are better than 25 degrees cooler
than a conventional carburetor under all comparable conditions of engine
operation. This feature is primarily due to the fact that the float bowl,
containing the fuel, is suspended from the cover within the outer housing
of the carburetor and cooled by incoming air.
The carburetor presents a new
ease of service to the service mechanic. By the simple removal of the
eight outside cover screws and the disconnection of the fuel line, the
cover and bowl assembly may be removed from the outer housing for cleaning
or inspection. Only in rare instances will the air cleaner and entire
carburetor be removed from the engine. The cover and bowl assembly, which
is the very heart of the carburetor, contains all the calibrated parts of
the carburetor. This unit may also be purchased as a service assembly,
thereby eliminating the need for a complete replacement
carburetor.
Of importance also is the need
for only four simple but important external adjustments. These are the
Choke Rod, Unloader, Fast Idle, and Accelerating Pump Discharge
Adjustments.
Since carburetion is dependent
upon both compression and ignition, the carburetor should always be
adjusted last in engine tune-up. The fuel systems within the carburetor
are basically simple and can be readily traced and
understood.
(The following illustrations are
schematic)