Float (Fuel Inlet) Circuit - Jeep J-10 Series 1982 Technical & Service Manual

FUEL SYSTEMS 1J-47
CARBURETOR MODEL BBD-2
VENTURI
Carburetor Circuits 1J-47
Carburetor Overhaul U-50
Carburetor Replacement U-50
General 1J-46
GENERAL
The Carter Model BBD two-venturi carburetor in
corporates three lightweight aluminum assemblies, the
air horn, main body and throttle body (fig. 1J-92).
The air horn contains the choke valve assembly, me
chanical linkage for accelerator pump and metering
rods, and bowl vent.
The main body contains the fuel bowl, accelerator
pump, vacuum piston and metering rod assembly, ven
turi assembly and solenoid.
The throttle body contains throttle valves and levers,
choke housing, choke vacuum diaphragm and idle mix
ture adjustment screws.
Identification
The carburetor is identified by a code number and
build date. Both are stamped on the identification tag.
Each carburetor build month is coded alphabetically
beginning with the letter A in January and ending with
the letter M in December (the letter I is not used). The
tag is attached to the carburetor and must remain with
the carburetor to assure proper identification (fig. 1J-
93).
CARBURETOR CIRCUITS
Five conventional circuits are used:
• Float (fuel inlet)
• Idle (low speed) Metering
• Main (high speed) Metering
• Pump (acceleration)
• Choke
Float (Fuel Inlet) Circuit
The float circuit maintains the specified fuel level in
the bowl to provide sufficient fuel to the metering cir
cuits for all engine operating conditions (fig. 1J-94).
Fuel flows into the bowl through a needle and seat
assembly controlled directly by dual floats hinged to the
float fulcrum pin.
When the fuel in the bowl fills to the proper level, the
float lever pushes the needle toward its seat and re
stricts incoming fuel, admitting only enough to replace
that being used.
CHOKE
VACUUM
DIAPHRAGM
DASH POT
Idle Speed Control 1J-49
Service Adjustment Procedures 1J-55
Specifications 1J-57
CHOKE
LINKAGE
HOUSING
BOWL
VENT
ROLLOVER
CHECK VALVE
AND BOWL VENT
IDLE MIXTURE
ADJUSTMENT
SCREWS (SEALED)
FUEL
INLET
VACUUM SOLE-VAC
NIPPLE HOLDING
SOLENOID
ADJUSTMENT
SCREW
81125A
CHOKE LINKAGE
HOUSING
CHOKE COVER
FASTENERS
Fig. 1J-92 Model BBD Carburetor Assembly
81125C