DeSoto Carburetors for old Desoto's : DESOTO MODEL S10 SIMPLIMATIC TRANSMISSION 1942

Form 6497A—Canadian
DE SOTO EGI
April, 1942 Reprinted April, 1946
MOTOR SERIAL NUMBER
S 10- 100 I and higher
CAR SERIAL NUMBER 9-949-05I and hi .her
EG I Carbureter also used on 1942
Chrysler "C34" Cars equipped
with Simplirnatic Transmission.

DESOTO MODEL S10 SIMPLIMATIC TRANSMISSION 1942

B-B DOWN-DRAFT CARBURETER—MODEL Eel, $35.30
A $7.50 exchange allowance is deducted from the list price if buyer turns in old carbureter.
CARBURETER SPECIFICATIONS
For De Soto Six Cylinder Engine: 3-7/16 Inch Bore, 411/4 Inch Stroke
Dimensions: Flange size, II/2 inch (38.1 mm). Throttle bore, I-I I/16 inch (42.86 mm). Moir venturi, I-II/32 inch (34.13 mm) I. D.
Float Setting: Top of float 1/16 inch (1.59 mm) below top surface of carbureter bode casting. (Plus or minus 1/64 inch (.397 mm).
Vent: Outside none. Inside balance vent .218 inch diameter (5.54 mm).
Gasoline Intake Needle: Triangular, horizontal No. 44 (2.18 mm) drill in needle seat.
Idle Orifice Tube: Jet size .0276 inch (.70 mm) drill. Idle passage air bleed, in body, size .063 inch (1.60 mm) diameter. Economizer in body, size .053 inch (1.35 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 .088 to .092 inch (2.24 to 2.34 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: 1/2 to 11/2 turns open. For richer mixture turn screw out. Do not idle engine below 300 r.p.m. or 6 miles per hour.
Main Metering Screw: Calibrated to flow 312 to 316 cc per minute. (Do not gauge for size. If in doubt replace with new part.)
Main Vent: Through diffuser (air bleed inside bowl). Size .0315 inch (.80 mm) drill.
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 .0413 inch (1.05 mm) drill.
Accelerating Pump: Type—delayed action.
Stroke—Summer setting (inner hole, short stroke). Intermediate setting (center hole).
Winter setting (outer hole, long stroke).
Pump intake passage, size .115 to .120 inch (2.93 to 3.05 mm) diameter in body.
Pump discharge passage: Restriction (under ball check) size .062 to .065 inch (1.57 to 1.65 mm) diameter in body. Pump (discharge) jet size, .0374 inch (.95 mm) drill.
Pump Adjustment: 26/64 inch plunger travel—full throttle position, medium stroke. Use gauge TI09-1175.
Choke: Manua—Butterfly type, with pressure relief poppet valve. Interconnected to open throttle valve to fast idle position when choke is in use.
Slow Closing Throttle: Dash pot with discharge (By-Pass), size .0197 (.5 mm) drill, through valve cage.
Vacuum Spark Port: Slot (round end) type; size .040 by .110 inch (1.016 by 2.794 mm). Top of port .035 to .041 inch (.89 to 1.04 mm) above top edge of valve.
Motor Tune-Up--Be Accurate! Always Use Feeler Gauges!
CAUTION: Change worn or leaky flange gaskets. Tighten manifold bolts and test compression before adjusting carburetor.
Use Motor Gauge
Breaker Points to Open:
Top Dead Center
VALVE CLEANFlNCr
Set Valves (Hot) Intake .008" Exhaust .010"
Float Setting Use Gauge 1/16 Inch
Idle Adjustment Screw Setting
1/2 to 11/2
Turns Open
Spark Plug Gap .025"
Se+
Breaker Points
.020"
CARBURETER ADJUSTMENTS
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 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 to specifications. If these adjustments do not correct the trouble. remove idle orifice tube and plug assembly. Clean tube and passages with compressed air.
If acceleration is not satisfactory remove pump jet and clean with compressed air. However, it is usually advisable to replace the pump jet. as its cost is nominal. All jets must be seated gasoline tight. Poor acceleration may be due to damaged or worn plunger leather in accelerating pump, sediment in pump cylinder or clogged intake ball check at bottom of pump cylinder and discharge ball check in die-charge passage. If plunger is removed from cylinder, us. care in installing to avoid damage to plunger leather.