DeSoto Carburetors for old Desoto's : DESOTO MODELS SF AIRSTREAM SG AIRFLOW 1935

Form 61398—Canadian
DE SOTO E6FI
FEBRUARY, 1935
Reprinted March, 1945
CAR SERIAL NUMBERS
Model "SF"—9664001 and higher
Model "SG"—9603436 and higher

MOTOR SERIAL NUMBERS Model "SF"—SFI6I7 and higher Model "SG"—SGIOOI and higher

DESOTO MODELS SF AIRSTREAM SG AIRFLOW 1935

DOWN-DRAFT CARBURETER-MODEL E6F I-LIST PRICE $29.40
A $5.00 exchange allowance is deducted from the list price if buyer turns in the
carburetor which is replaced by an E6F2—List Price $29.40
CARBURETER SPECIFICATIONS
De Soto Six Cylinder Engine: 3% Inch (85.725 mm) Bore, 41/2 Inch (114.30 mm) Stroke
Dimensions: Flange size, 11/2 inch (38.1 mm). Main Metering Screw: Calibrated to flow 280 to 284 CC per
Throttle bore, I-II/16 inch (42.86 mm). minute. (Do not gauge for size. If in doubt, replace with
Main venturi, 1-9/32 inch (32.54 mm) I. D. new part.)
Float Setting: Top of float 5/64 inch (1.98 mm) below top surface of carbureter body casting. (Plus or minus 1/64 inch (.397 mm).
Vent: (To float chamber) Outside: Size 3/16 inch (4.76 mm) drill.
Gasoline Intake Needle: Triangular, horizontal. No. 42 (2.37 mm) drill in needle seat.
Idle Orifice Tube: Jet size .0276 inch (.70 mm) drill.
Idle passage air bleed (in body) size .061 inch (1.55 mm) diameter.
Economizer in body—size .049 inch (1.25 mm) diameter.
Idle Ports: Upper port. Keyhole type; length, .128 inch (3.25 mm); width, .027 inch (.69 mm). .063 inch (1.60 mm) diameter hole at top.
Top of port located .076 to .080 (1.93 to 2.03 mm) above top edge of valve.
Lower port size, .053 to .057 inch (1.35 to 1.45 mm) drill. (For idle adjustment screw.)
Set Idle Adjustment Screw: 1/4 to I turn open. For richer mixture turn screw out. Do not idle engine below 300 r.p.m. or 6 miles per hour.
Vent Tube: Air bleed through plug in diffuser, size .0315 inch (.80 mm) drill.

Main Vent Tube:
Side Holes:
2—.0354 inch (.90 mm), 21/64 inch (8.33 mm) from end. 2—.0354 inch (.90 mm), I-I/64 inch (25.8 mm) from end.
Step-up Jet: (Power Orifice) .0374 inch (.95 mm) drill.
Accelerating Pump: Type, delayed action.
Stroke: Summer setting (inner hole, short stroke) I/4 inch (6.35 mm).
Intermediate setting (center hole) 7/16 inch (11.11 mm). Winter setting (outer hole, long stroke) 5/8 inch (15.88 mm). Pump intake passage, size .115 to .120 inch (2.93 to 3.05 mm) diameter in body.
Pump needle seat size .062 to .065 inch (1.58 to 1.65 mm) diameter in body.
Pump (discharge) jet size .0354 inch (.90 mm) drill.
Choke: Manual—butterfly type, with pressure relief poppet valve, inter-connected to open throttle valve to fast idle position when choke is used.
Motor Tune-Up—Be Accurate! Always Use Feeler Gauges!
CAUTION: Change worn or leaky flange gaskets. Tighten manifold bolts and test compression before adjusting carbureter.
Use Timing Light or Motor Gauge
Breaker Points to Open:
Model SF—(Cast Iron Head—
6 to I Compression) Top Dead Center
Model SG—(Standard Aluminum Head—
6.5 to I Compression)
5° or .011" After Top Dead Center
Model SG—(Special Aluminum Head—
7 to I Compression)
7° or .021" After Top Dead Center
CARBURETER ADJUSTMENTS
VALVE CLEARANCE
Spark Plug Gap .025"
Set
Breaker Points
.022"
Set Valves Intake .005" Exhaust .007"
Use Gauge 5/64 Inch
Idle Adjustment Screw Setting
1/4 to I
Turn Open
If carbureter loads up after considerable service, check float level. Wear on lip of float lever will raise float level. Before adjusting float, be sure float lever pin plug is firmly seated. Reset float level by bending lip of float lever away from needle to raise level, or bend lip toward needle to lower float level. Bend vertical lip of float only.
If motor stalls while idling, set throttle lever adjusting screw so motor runs approximately 300 r.p.m. Then set idle adjustment screw as instructed above. If these adjustments do not correct the trouble, remove idle orifice tube and plug assembly and clean with compressed air.
If acceleration is not satisfactory remove pump jet and clean with compressed air. Also examine pump link setting. Pump link has three holes giving short, medium and long strokes. If link is set to short stroke, reset to give longer stroke to pump piston. In hot weather, high altitudes, or when high test gasoline is used, connect pump link in inner
Caution: Do not attempt to gauge metering jet with drills.hole, giving shorter stroke.
Maximum economy is secured only when breaker points, spark plugs, valves and motor timing are set to manufacturer's specifications. After motor is properly tuned, the following should also be done to insure satisfactory performance and economy:
(a) Float level must be set as above.
(b) Ball check in step-up valve assembly must seat and move freely. When reassembling, valve housing must be screwed in tight against seat.
(c) Step-up push rod must move freely in upper and lower guides.
(d) Step-up piston in upper casting should not bind and must be free of dirt.
(e) Main metering screw can be replaced with leaner than standard metering screws, for altitude or high test fuel.
These jets have been flow-tested, to insure correct fuel flow.