1953 JEEP DJ fuel pressure

Dl
DAUNTLESS
V-6
ENGINE

FIG.
Dl-41—WATER
PUMP
AND
TIMING CHAIN COVER BOLT LOCATION
Cover
Bolts

alternately and evenly 8 to 12 lb-ft. [1,10 a 1,66

kg-m.].

Dl-88.
Install
Crankshaft
Vibration
Damper

a.
Lubricate
the vibration damper hub
before
in­
stallation to prevent
damage
to the crankshaft
front oil seal during installation and when the

engine
is first started.
b.
Install
the vibration damper on the crankshaft.
Secure it with its attaching flat washer and screw.

Torque
the screw to a minimum of 140 lb-ft.
[19,35
kg-m.].

Dl-89.
Install
Crankshaft Pulley
Secure the crankshaft pulley to the crankshaft

vibration
damper with six screws. Torque screws 18 to 25 lb-ft. [2,5 a 3,4 kg-m.].

Dl-90.
Install
Oil
Level
Dipstick

Insert
oil level dipstick
into
the dipstick tube.

Dl-91.
Install
Oil
Pressure Sending Unit

Install
oil pressure sending unit in cylinder block.
Connect electrical wiring harness to unit.

Dl-92.
Install Starting Motor

Secure starting motor and
solenoid
assembly to
the flywheel housing and cylinder block with two attaching screws. Torque screw, which attaches this
assembly to the flywheel housing, 30 to 40 lb-ft. [4,1 a 5,5 kg-m.]. Torque screw, which attaches

bracket
to cylinder block, 10 to 12 lb-ft. [1,4 a 1,7 kg-m.].
Dl-93.
Install
Oil
Filter

Install
a new oil filter
element
at oil filter nipple,
at
left
side
of timing chain cover. Torque 10 to 15 lb-ft. [1,38 a 2,07 kg-m.].

D1-94. Install Water Pump
Be
certain that mating surfaces of the water pump

and
timing chain cover are clean.
Install
a new
gasket
on the pump flange. Secure the pump and
alternator adjustment bracket to the cover with
nine attaching bolts. Torque
bolts
6 to 8 lb-ft. [0,83 a 1,10 kg-m.]. Refer to Fig. Dl-41.

D1-9S.
Install
Cooling Fan
Secure the cooling fan, fan hub, and fan drive
pulley to the water pump shaft
flange
with four
attaching screws. Torque screws 17 to 23 lb-ft. [2,35 a 3,18 kg-m.].

Dl-96.
Install
Alternator
and Fan
Belt

Mount the alternator and bracket assembly on
right
cylinder head with two attaching screws.

Torque
screws 30 to 40 lb-ft. [4,1 a 5,5 kg-m.].

Fasten
the alternator
loosely
to its adjustment
bracket
with attaching flat washer and nut.
Install

the fan
belt
on its pulleys. Pivot the alternator
outward,
away from cylinder block, to apply fan

belt
tension. Adjust fan
belt
tension to 80 lb. [36,2 kg.];
tighten
alternator-to-adjustment bracket
nut to secure adjustment
setting.
Connect wiring
harness to alternator.

Dl-97.
Install
Fuel Pump

Install
two mounting
bolts
and new
gasket
on

flange
of fuel pump. Secure pump to timing chain cover with screws; torque screws 17 to 23 lb-ft. [2,35 a 3,8 kg-m.]. Connect
output
fuel line to
pump.

Dl-98.
Install Exhaust Manifold

Secure each of two exhaust manifolds to corre­
sponding cylinder head with five attaching screws,
and
one nut. Torque screws and nut 15 to 20 lb-ft. [2,07 a 2,8 kg-m.]. See Fig. Dl-42.

Dl-99.
Install Distributor

Insert
distributor drive gear
into
distributor mount-
FIG.
Dl-42—EXHAUST
MANIFOLD INSTALLATION

1—Torque
Bolts—15
to 20
lb-ft.
[2,07 a 2,8
kg-m.]

102

'Jeep'
UNIVERSAL
SERIES SERVICE
MANUAL

Dl
Dl-104.
SERVICE
DIAGNOSIS

Poor Fuel Economy
Ignition Timing Late or Spark Advance Inoperative

Carburetor
Float Setting Too High
Accelerator Pump Improperly Adjusted
Fuel
Pump Pressure High

Fuel
Line
Leakage

Fuel
Pump Diaphragm Leakage
Cylinder
Compression Low
Valves Do Not Seat Properly
Spark
Plugs
Defective

Spark
Plug Cables
Defective

Ignition
Coil
or Capacitor
Defective

Carburetor
Air Cleaner Dirty

Brakes
Drag
Wheel Alignment Incorrect

Tire
Pressure Incorrect Odometer Inaccurate

Fuel
Tank
Cap Clogged or
Defective

Muffler or Exhaust Pipe Clogged or Bent

Lack
of
Power
Cylinder
Compression Low
Ingitdon Timing Late

Carburetor
or
Fuel
Pump Clogged or
Defective

Fuel
Lines Clogged
Air
Cleaner Restricted
Engine Temperature High Valves Do Not Seat Property

Valve
Timing Late Intake Manifold or Cylinder Head
Gasket Leaks
Muffler or Exhaust Pipe Clogged or Bent
Spark
Plugs Dirty or
Defective

Breaker
Point Gap Incorrect
Breaker
Points
Defective
Ignition
Coil
or Capacitor
Defective

Electrical
Connection Loose
Broken
Valve Spring

Broken
Piston Ring or Piston
Cylinder
Head Gasket
Defective

Distributor Cap Cracked

Low
Compression
Valves Not Seating Properly Piston Rings Seal Poorly
Valve
Spring Weak or Broken
Cylinder
Scored or Worn
Piston Clearance Too Great

Cylinder
Head Gasket Leaks

Burned
Valves and
Seats
Valves Stick or Are Too Loose in Guides
Valve
Timing Incorrect

Valve
Head and Seat Have Excessive Carbon
Engine Overheats

Valve
Spring Weak or Broken

Valve
Lifter Seized or Collapsed
Exhaust
System Clogged
Valves Sticking

Valve
Stem Warped

Valve
Stem Carbonized or Scored

Valve
Stem Clearance Insufficient in Guide

Valve
Spring Weak or Broken

Valve
Spring Distorted
Oil
Contaminated

Overheating
Cooling System Inoperative
Thermostat Inoperative Ignition Timing Incorrect

Valve
Timing Incorrect
Carbon
Accumulation Excessive

Fan
Belt Loose
Muffler or Exhaust Pipe Clogged or Bent

Oil
System Failure
Piston Rings Worn or Scored
Popping,
Spitting,
Detonation
Ignition Timing Incorrect

Carburetion
Improper

Carbon
Deposit
in Combustion
Chambers Excessive
Valves Not Seating Properly
Valve
Spring Broken
Spark
Plug Electrodes Burned
Water or Dirt in
Fuel
Fuel
Line
Clogged
Valve
Timing Incorrect

Excessive
Oil
Consumption
Piston Rings Stuck in Grooves, Weak,
Worn,
Broken, or Incorrectly Fitted

Crankshaft
Main Bearings or
Connecting Rod Bearings Have
Excessive Clearance
Gaskets or Oil Seals
Leak

Cylinder
Bores Worn, Scored,
Out-of-Round or Tapered
Pistons Have Too Great Clearance to Cylinder Bores
Connecting Rods Misaligned High Road Speed
High Temperature

Crankcase
Ventilation System Inoperative
Bearing Failure
Crankshaft
Bearing Journal Rough or Out-of-Round

Oil
Level Low
Oil
Leakage

Oil
Dirty
Oil
Pressure Low or Lacking
(Oil
Pump Failure)

Drilled
Passages
in Crankshaft or
Crankcase
Clogged

Oil
Screen Dirty
Connecting Rod Bent 105

'Jeep*
UNIVERSAL SERIES SERVICE
MANUAL

E

FUEL
SYSTEM
Contents

SUBJECT
PAR.

GENERAL
E-1 Dash

FUEL
EVAPORATIVE EMISSION
?*^r
CONTROL SYSTEM
..E-2
Canister
.E-3 . Demand Valve E-4

Fuel
Tank.
.E-5
Inspection Test. E-8
Sealed Gas Cap. E-7

Servicing
System E-9
Vapor
Separator or Expansion
Tank
E-6

CARBURETOR
—
HURRICANE F4 ENGINE.
. .
......
..... ,. . .E-10 Accelerating Pump System.............. .E-19 Accelerating Pump Maintenance E-20

Carburetor
Reassembly
E-2
2

Carburetor
Disassembly E-21
Choke
System E-17
Dash
Pot Adjustment E-44

Fast
Idle Adjustment E-18
Float
Adjustment E-12
Float
System. E-ll
High-Speed System . .E-15
Idle
Adjustment .E-14

Low-Speed
System . E-13
Metering Rod Adjustment E-16

CARBURETOR
~r
DAUNTLESS V-6 ENGINE
.E-25
Accelerator Pump Adjustment E-41 Accelerator Pump System. . E-30

Air
Horn Body Assembly E-39
Air
Horn Body Removal and Disassembly.
E-33

Carburetor
Cleaning and Inspection E-36
Carburetor
Removal E-32
Choke
System E-31

Curb-Idle
Speed and Mixture Adjustment. .E-42

E-1. GENERAL
The
fuel system of the Jeep Universal vehicle,
whether equipped with a Hurricane F4 or Daunt­

less
V-6 Engine,
consists
of the fuel tank, fuel lines, fuel pump, carburetor and
air
cleaner.
Fig. E-1, E-2.
Vehicles equipped with a
Fuel
Evaporative
Emis­

sion Control System
also
include a
non-vent

pressure and vacuum
sensitive
gas cap, a liquid
expansion and vapor separator tank, a carbon filled vapor
storage
canister, and a vapor purge line. Service information pertaining to the
Fuel
Evap­

orative Emission Control System is outlined in

Par.
E-2 through
E-9.
Refer to Figs. E-3 and E-4.
The
most
important
attention
necessary to the fuel
system is to
keep
it clean and free from water. It should be periodically inspected for leaks.

CAUTION—Whenever
a vehicle is to be stored for

an
extended
period, the fuel system should be com­

pletely
drained, the
engine
started and allowed to
run
until the carburetor is emptied.
This
will
avoid
oxidization of the fuel, resulting in the formation of
SUBJECT
PAR.
Pot Adjustment .E-44

nal
Carburetor Adjustments.........E-40

Idle
Adjustment
.
E-43 System . . .E-26

Bowl
Body Assembly E-38

Fuel
Bowl Body Disassembly E-34

Idle
System E-27

Main
Metering System E-28
Power System . E-29
Throttle
Body Assembly .E-37

Throttle
Body Removal, and Disassembly. .E-35

FUEL
PUMP
—
HURRICANE F4 ENGINE.
E-45, 54, 60

Cleaning
and Inspection.............
.E-57,
63 Disassembly E-46, 56, 62
Installation E-59, 65
Reassembly
.E-47,
58, 64
Removal
E-55, 61

Testing.
E-49, 50, 51, 52, 53, 66

Vacuum
Pump E-48

FUEL
PUMP
—
DAUNTLESS V-6 ENGINE
E-67
Removal
E-68

AIR CLEANER
—
CARBURETOR
E-69
ACCELERATOR
LINKAGE
.E-70

FUEL
TANK
AND
LINES
E-71
Float
Unit . .E-76
Fuel
Lines E-77
Fuel
Tank
. . .E-72

Fuel
Tank
Cap E-75

Fuel
Tank
Installation. E-74
Fuel
Tank
Removal E-73

SERVICE
DIAGNOSIS
E-78

SPECIFICATIONS.
E-79
gum in the units of the fuel system. Gum formation
is similar to hard varnish and may cause the fuel
pump valves or the carburetor
float
valve to be­
come
stuck or the filter screen blocked. Acetone or commercial fuel system cleaners
will
dissolve

gum formation. In
extreme
cases
it
will
be necessary
to dissassemble and clean the fuel system. In
most

cases, however, a
good
commercial fuel system sol­
vent
used in accordance with the manufacturer's
instructions or one pint [0,6 ltr.] of
acetone
placed
in
the fuel tank with
about
one gallon [4,5 ltr.]
of
gasoline
will
dissolve
any
deposits
as it
passes

through the system with the
gasoline.

E-2.
FUEL
EVAPORATIVE EMISSION CONTROL SYSTEM

Description and Operation

•
Refer to Figs. E-3 and E-4.

The
Fuel
Evaporative Emission Control System
is
designed
to reduce fuel vapor emission that 109

E

FUEL
SYSTEM

FIG.
E-1—FUEL SYSTEM—EARLY MODEL—F-4 ENGINE 1—
Fuel
Line
To Carburetor 4—Accelerator Treadle
2— Carburetor 5—Fuel Tank and Gauge
3— Choke Cable 6—Fuel Pump

FIG.
E-2—FUEL SYSTEM—EARLY
MODEL—V-6
ENGINE 1—
Fuel
Line
To Carburetor 5—Fuel Tank and Gauge

2—
Carburetor 6—Fuel Pump
3— Choke Cable 7—Fuel
Line
To Fuel Pump

4—
Accelerator
Treadle 8—Fuel Return
Line
normally
vents
to the atmosphere from the vehicle
fuel system.

The
fuel vapor system consists of internal fuel tank
venting, a vacuum /pressure fuel tank cap, a vapor
separator or expansion tank, vapor canister, and closed external carburetor venting. The same basic
system is used on all 'Jeep' vehicles, as shown in
Fig. E-3.

This
system involves means of trapping the fuel
vapors through the use of a charcoal canister which
absorbs the vapor and stores it until it can be re­ moved to be burned in the
engine.
This
removal is
performed by drawing
these
vapors through the purge line
into
the crankcase ventilation system

which
in
turn
enters the intake manifold. In ad­ dition to the canister, the fuel tank requires a sealed
gas cap and extra
vents
to a liquid separator or
expansion tank.
This
prevents liquid
gasoline
from entering the vapor system.
Thus,
as vapors are generated in the fuel tank,
they
flow through the

liquid
separator or expansion tank to the canister

and
are routed to the intake manifold through the 110

'Jeep*
UNIVERSAL
SERIES
SERVICE
MANUAL

E

FIG.
E-3—FUEL EVAPORATIVE EMISSION CONTROL SYSTEM- HURRICANE F4 ENGINE
A—Side
View

1—
Charcoal Canister
2— Purge
Line

3—
Fuel
Tank
4—
Fuel
Filler
Hose 5—
Non-Vented
Gas Cap
B—Plan
View

6—
Vapor
Separator
or Expansion Tank 7—
Fuel
Gauge

8—
Fuel
Line-to-Fuel Pump

9—
p.C.V.
Crankcase
Valve

10—Fuel
Pump

crankcase
vent system. The charcoal canister in­
corporates an integral demand valve
which
regu­

lates
vapors entering the canister as
well
as a
limit
fill
valve
to control air trapping during tank
fill.
The
Fuel
Evaporative Emission Control System
incorporates the following new or modified parts:

E-3.
Canister
The canister used for the vapor control system has
provisions for containing activated charcoal gran­ ules. The material used for the canister body is a

special,
fuel resistant, heat stabilized nylon. At the top of the canister there is the demand valve which
has connections; one vents the vapor to the canister
while the other connection joins the canister to the purge system. These
tubes
enter the canister on

opposite
sides of a baffle which permits uniform
vapor distribution throughout the canister. The
bottom
of the canister is fitted with a filter element
that allows fuel tank venting to atmosphere after vapors are trapped in the activated charcoal.

E-4.
Demand Valve

The
demand valve is integral with the canister. It
is essenitally a combination pressure regulator and

vacuum
relief valve.
This
valve regulates the rate
of vapor
flowing
from the fuel tank into the canister.
The
valve consists of a housing, a spring loaded
diaphragm,
a diaphragm cover, and a vacuum

relief
valve. The operation of the unit is such that
as tank vent pressure increases the diaphragm lifts,
permitting vapor to enter the canister. The pres­
sure
under which this occurs is 4" to 6"
H2O.
This

action regulates the flow of vapors into the canister
under severe soak and operation conditions (temp, changes), but generally prohibits the flow of vapor 111

E

FUEL
SYSTEM

9
©

FIG.
E-4—FUEL
EVAPORATIVE
EMISSION
CONTROL
SYSTEM-
DAUNTLESS
V-6
ENGINE
A—Side
View
1—
Charcoal
Canister

2—
P.C.V.
Crankcase
Valve

3—
Purge
Line

4—
Fuel
Tank
5—
Fuel
Filler
Hose
B—Plan
View
6—
Non-Vented
Gas Cap 7—
Vapor
Separator or Expansion
Tank

g—Fuei
Gauge

9—Fuel
Line-to-Fuel
Pump

10—Fuei
Return
Line

during
normal temperature vehicle operation, thus
minimizing
driveability problems. An additional
feature of this valve is a built-in vacuum relief

which
allows inward air flow under negative fuel

tank
pressure conditions. The valve housing con­
tains the normal tank vent and purge connections.

E-5.
Fuel Tank

The
fuel tank is external expansion type.
Fuel

tank
venting is accomplished by several vapor
lines which lead to the vapor separator or expan­
sion tank. The vapor lines which lead from the
fuel tank are located at the front and
rear
so that
during
any inclination of the vehicle, at least one
line
will
be open to vent at all times.
E-6.
Vapor Separator
or
Expansion Tank

The
vapor separator is chambered so that the
rear
fuel tank vent lines lead into a separate chamber

with
a fuel shutofl valve.
This
prevents solid fuel
from
flowing from the fuel tank to the vapor can­
ister during uphill operation or parking of the
vehicle. A single vapor vent line leads from the fuel
vapor separator to the vapor collection canister
where fuel vapors are stored until they can be drawn into the
engine
and burned.

The
expansion tank allows expansion of the fuel as

required
during temperature changes and simul­ taneously
becomes
a liquid trap that only allows
vapors to pass.
E-7.
Sealed
Gas Cap

The
sealed gas cap is designed to allow no vapors to
discharge into the atmosphere under normal
operation of the system. If the system
becomes
plugged or a failure of the demand valve occurs 112

'Jeep*
UNIVERSAL
SERIES
SERVICE
MANUAL

E
there is a relief valve that
opens
to reduce high
(dangerous) pressures in the fuel tank. In con­

junction
with the pressure relief valve there is a
vacuum
relief valve to
stop
collapse of the fuel

tank
in case of a plugged system or failure of the demand valve. When replacing the gas cap, the
same type must be used as originally installed.

E-8.
System Inspection Test

The
fuel emission vent system should be checked

carefully
to ensure the absence of any leaks to the
atmosphere of either liquid or vapor which might
affect the accuracy, safety, or performance of the control system.

To
assure that the sealed system has been properly

installed,
the following
test
procedure has been
developed.
Disconnect the vent line from the fuel tank system
to the activated charcoal canister, induce l/i p.s.i.
air
pressure. If this pressure can be maintained for

a
few seconds the vent system is assured to be sealed. DO NOT add air pressure to the canister
because damage can occur to the demand valve if
care
is not taken.

E-9.
Servicing the System

Periodic
Maintenance — Replace carbon canister filter at
12,000
miles
[19,200
km.] or 12 month in­tervals (more
often
for operation in dusty areas).

This
is the only regular maintenance service

required.

Canister
Filter
Replacement — Disconnect
hoses

from
top of canister, remove canister from mount
-

t
FIG.
E-5—CARBURETOR—
F4 ENGINE,
EARLY
MODEL
1—
Choke
Clamp
Bracket

2—
Choke
Shaft and
Lever
Assembly

3—
Fuel
Inlet
Elbow

4—
Bowl
Vent Tube 5—
Idle
Air Adjusting
Needle
6—
Throttle
Lever
and Shaft Assembly
7—
Idle
Speed Adjusting Screw
8—
Fast
Idle Connector Rod ing bracket. Remove cover from
bottom
of canister
by pulling it down to
disengage
clips. Remove and
discard
polyurethane filter element
(squeeze
ele­

ment out from under retainer bar).
Install
new
filter by squeezing element under retainer bar and positioning it evenly around entire
bottom
of
canister with
edges
tucked under canister lip, snap

bottom
cover in place, reinstall canister on bracket

and
reconnect
hoses.

Vapor
line
hoses
used in this system are made of

special
rubber material.
Bulk
hoses
are available for
parts
service.
Ordinary
rubber
hose
should not be
used to service vapor lines as they are subject to deterioration and may clog the system.
Liquid

vapor separators or expansion tanks and canisters

are
serviced as complete units only.
Canister
air filters, however, are serviced separately.

E-10.
CARBURETOR
—
HURRICANE
F4
ENGINE

A
single-barrel manual choke, down-draft carbure­
tor (Fig. E-6) is used on the
Hurricane
F4 engine.
The
carburetor is internally vented by a tube
opening located in the air horn body of the
car­

buretor.
This
opening is connected by a rubber
tube to the air
outlet
horn of the air cleaner thus
allowing only filtered atmospheric pressure air
to enter the float chamber for balance pressure
of the carburetor fuel.

Note:
A carburetor with a specific flow character­

istic
is used for exhaust emission control. The
carburetor
is identified by a number, and the correct

carburetor
must be used, when replacement is
necessary.

Early
production models
CJ-3B,
CJ-5,
CJ-5A,
CJ-6,
and
CJ-6A
have a
Carter
YF-938SD
carbure­
tor superseding the earlier
YF-938SC,
YF-938SA,

or
YF-938S
models.

Note."
Conversion kits for changing earlier models
to SD models are available. See Par E-23. It is recommended that when a carburetor is converted
that a tag be fashioned stamped with the new model number and installed under one of the air

horn
screws.
Look
for such a tag to determine if
the carburetor has previously been converted.

Carburetors
listed above are all in the same YF
series and have only minor differences. Descriptions
and
repair procedures given in the following
para­
graphs apply equally to all
YF-series
carburetors.
YF-series
carburetors employ manual and vacuum
control of the metering rod and accelerator pump.
The
carburetor controls and vaporizes the fuel
through five separate systems: float system, low-
speed system, high-speed system, choke system,

and
accelerating-pump system. A description of the function and operation of each system provides an over all description of the carburetor.

For
identification, the series designation is stamped
on the body under the name
Carter
and the model
designation is stamped on a flange protruding
from
the body.

Note:
When checking for carburetor icing causes,
also check the vacuum-pump-to-manifold vacuum
line connector. 113

'Jeep'
UNIVERSAL
SERIES SERVICE
MANUAL

E

FIG.
E-14—DRILLING CARBURETOR JET 1—
Drill
(#68 size)

2—
Accelerator
Pump Discharge Jet
E-24.
Steep-Grade
Carburetor
Kit

In
the
field
where a vehicle equipped
with
Carter carburetor 938-S is required to
idle
on
steep

slopes,
flooding
of the carburetor sometimes results.

A
steep-grade
carburetor kit is available that
will

allow satisfactory
idle
operation under this condi­

tion.
This kit (Part
No.
#94481,
Carter # 75-960U)
contains a metering rod, a metering rod jet, and a
plug.

To
install
this kit, replace the standard metering

rod
and metering rod jet
with
those
contained in the
kit.
Place the small
brass
plug
in the accelerator
pump
well.
Exert
finger pressure only when in­

stalling
this
plug.
Forcing the
plug
in too far
will
damage
the accelerator
jet.
Make certain the meter­

ing
rod and
float
level
are set to specifications.

When
reworking
the carburetor to include this
steep-grade
kit, check to determine if the seal (Carter #121-172) and retainer (Carter #136-152)
are installed. If
these
parts are not present, they

should
be installed.
FIG.
E-15—CARBURETOR-
DAUNTLESS V-6 ENGINE 1—
Fuel
Inlet

2—
Choke

3—
Choke
Cable
Bracket

4—
Idle
Speed Adjusting Screw 5—
Idle
Fuel-air
Mixture Screws
E-25.
CARBURETOR
—
DAUNTLESS
V-6

ENGINE

A
double-barrel, manual choke, down-draft car­
buretor (Fig. E-15) is used on the Dauntless V-6 engine.
Note: A carburetor
with
a specific
flow
character­

istic
is used for exhaust emission
control.
The
carburetor is
identified
by a number, and the
correct carburetor must be used, when replacement
is
necessary.

The carburetor
fuel
bowl
is located
forward
of
the main bores. The carburetor is compact in design

in
that all of the
fuel
metering is centrally located.
See Fig. E 16.

This
carburetor
uses
a calibrated cluster design

with
main
well
tubes,
idle
tubes, mixture
passages,
air
bleeds and pump jets in one removable as­

sembly.
This cluster assembly can be easily re­

moved
for cleaning and inspection purposes. It is

mounted
on a
flat
portion
of the carburetor
bowl

in
front
of the main
venturi.
The
idle
and main

well
tubes
are precision
pressed
fit in the cluster
body.
They cannot be serviced separately. The

main
nozzles and
idle
tubes
are
suspended
in the
main
wells of the
float
bowl.

The main metering jets are of the
fixed
type. A
system of calibrated air bleeds gives correct
fuel-

air
mixture throughout all operational
ranges.
This
carburetor has a vacuum-operated power sys­

tem
which
supplies extra
fuel
when needed. Power
mixtures
are regulated by drop in engine
manifold
vacuum,
regardless of throttle opening. Thus, addi­

tional
fuel
is supplied for power mixtures accord­

ing
to engine demands.
The accelerator pump plunger has a vapor vent

ball
in its head. This
ball
and its
seat
form
a valve

to
vent any
fuel
vapors
which
form
in the pump

well
to the
fuel
bowl
during hot-engine operation.
This
ensures
that the pump
well
and
passages
will

be primed
with
solid
fuel
at all times and im­ proves accelerator pump action. The carburetor is
internally
vented through a hole

in
the air horn.
FIG.
E-16—FUEL BOWL BODY—TOP VIEW
1— Pump Return Spring 3—Power
Valve
2—
Main
Metering
Jets
4—Cluster Assembly
119