the throttle valve (F) is opened to a
degree sufficient suction is applied to the main discharge nozzle (II) in
the crossbar. As a consequence
the fuel begins to pass from the main nozzle, rather than through the idle
calibration of the Main Metering Jet (A) and Air Bleeds (C) in the crossbar
control and maintain the economical
fuel/air ratios throughout the 25-60 mph driving range.
provide additional fuel for sustained high speed operation or increased
road load power, the vacuum operated Power System delivers such fuel readily
direct manifold vacuum passage (M) within the carburetor to the engine intake
manifold operates this system.
At any manifold vacuum above =5"
Hg. the Power actuating
Piston (I) is held by suction in the "Up" position against the compression
of the Power Spring (K) consequently
no fuel passes through the ball type Power Valve (J). With
any decrease in vacuum below
5" Hg. the calibrated Power Spring (K) immediately forces the Power Piston
down, which unseats the spring
loaded ball (L) in the Power Valve (J). Fuel then passes readily
around the ball into the base of the
Main Well Support Assembly. The calibrated power restriction
(N) meters the fuel prior to joining the fuel from the main metering jet,
and is delivered to the
engine. Conversely as the manifold vacuum rises above 5" ll.(),.
the Power Piston is drawn
immediately to the "Up"
position and the engine returns to the economical part throttle mixtures
of the Carburetor.
is no adjustment required for the Part Throttle or Power Systems.