open exposing the discharge slot, the fuel-air
mixture flows from both the idle transfer slot and
|(2) MODEL 4150 G and MG - Fuel flows
from the secondary fuel bowl through the main
metering jet, up the idle well and throughthe idle
feed restriction. Then it crosses a short horizontal
passage and blends with idle air from the idle air
bleed. This fuel-air mixture flows down a vertical
passage to the idle adjusting needle.
|Part of this mixture flows into the idle
discharge passage and part into the idle transfer
passage. The fuel-air is discharged through the
idle discharge hole into the throttle bore below the
secondary throttle plate. As the throttle plate is
opened fuel-air is discharged into the throttle bore
from the idle transfer slot.
|(3) MODEL 4160 - Fuel flows through the
main metering restriction up the diagonal passage
through the idle restriction.
|The fuel then flows past the idle air
bleed and down a vertical passage. At the bottom of
this passage the fuel-air mixture flows into the
main body and down into the throttle body. Fsel is
discharged into the throttle body below the throttle
plates from the idle discharge slot.
|Secondary Idle and Transfer System|
|mixture to the other systems ONLY WHEN THE
FUEL IS AT THE SPECIFIED LEVEL.
|(4) MODEL 4160 WITH MECHANICAL
SECONDARYS - With the secondary throttle plates
closed the fuel flows through the main metering
restriction up the diagonal passage through the
idle restriction. The fuel then flows past the idle
air bleed and down a vertical passage. At the
bottom of this passage the fuel air mixture flows
into the main body and down into the throttle body.
The fuel is discharged into the throttle body below
the throttle plates from the idle discharge hole.
|All model 4160 carburetors have a balance
tube which runs from the secondary fuel bowl to the
primary fuel bowl. This tube prevents flooding in
the secondary fuel systems.
|B. IDLE SYSTEM - Because of driving
habits, some drivers would use the secondary side
very little or not at all. If the secondary system
remains inoperative over long periods the system
may become blocked with gum and carbonforma
tions. To prevent this condition, an idle system is
incorporated on the secondary side to insure clean
operation under various driver conditions.
|C. MAIN METERING - When the secondary
throttle plates are opened further, the pressure
differential within the carburetor causes the sec
ondary main metering system to function.
|The fuel enters the secondary metering
body from the fuel bowl through the main metering
restriction and up the vertical passage.
|(1) MODEL 4150 - Fuel flows from the
secondary fuel bowl through the secondary main
metering jet into the idle well, then up a vertical
passage through the idle transfer feed restriction
across a short passage. Here the fuel blends with
air coming from the idle transfer air bleed. This
fuel-air mixture flows down a vertical passage to
an entrance into the main body. From here it goes
down the main body into the throttle body and
discharges into the throttle bore below the second
ary throttle plate. As the secondary throttle plates
|As the fuel goes up the vertical passage it
passes the main well bleed. This fuel air mixture
passes into another short horizontal passage lead
ing into the main body and the discharge nozzle.
This fuel is discharged into the booster venturi
and then in the air stream of the carburetor