Flange Size: 1 1/8″,
Upper Well: Depth from stand pipe seat, 1/4″
Lower Well: 11/32″ ID
Float Level: Top of float to be 11/16″ from machined surface of casting at point opposite needle, with needle seated.
Inside Vent: No. 50 drill.
Gasoline Intake: Square vertical needle. No. 38 hole in needle seat.
Gas Line Connection: 5/16″
Low Speed Jet Tube: Jet, No. 70 drill.
Idle Port: Length .176″, Width: .030″. Opening above valve with valve closed tight: .032″ to .036″
By Pass: under idle port No. 53 drill.
Set Idle Adjustment Screw: 3/4 to 1 1/4 turn open. For richer mixture, turn screw in. Do not idle engine below 300 RPM with spark retarded.
Main Sell Jet No. 55 drill.
Multiple Jet Nozzle: Vertical jet, No. 48 drill. Top I.D. No. 26 drill size.
Accelerating Jets (Combination No. 70):
4 No. 60, 9/16″ from top.
2 No. 55, 1 5/16″ from top.
2 No. 55, 1 11/32″ from top.
Metering Rod: Diameter top, .070″; bottom .060″; length 5 1/64″.
Standpipe: Flare top 7/16″ ID with 5/16″ venturi. One No. 51 air hole in base. Two air slots .250″ – .254″ high by .380″ – .385″ wide.
Main Venturi: 1 1/16″ ID
Accelerating Pump: Low pressure type: Discharge jet, No. 76 drill; Feed to ball check, No. 45 drill. Connect plunger shaft to give longest stroke for winter driving, using shorter stroke for normal or hot weather.
Viewing Carburetor From Side Opposite Air Intake
Choker (compensating cone type): In venturi, lever at left. When open points down.
Throttle Lever: 1 1/4″ long at left side. In center of travel points up.
Tube Clamp: On air intake.
If carburetor loads up after considerable service, float level should be checked. Wear on lip of float level should be checked. Wear on lip of float lever will raise float level. Bending lip of float lever down will raise float level; bending lever up will lower float level. Only a slight bend is needed.
If motor stalls while idling, reset idle adjustment screw and throttle valve adjusting screw. If these adjustments do not correct the trouble, remove low speed jet tube and clean thoroughly with compressed air. Examine soldered joint in tube for air leaks and see that tube seats air tight in body casting, top and bottom. If not, replace with a new tube of identical specifications. Never change a low speed jet tube from one carburetor to another.
Increased resistance on foot throttle indicates a clogged pump jet. Pump jet should be removed and cleaned with compressed air, which, in many cases, will remove the dirt or lint. All jets and ball checks must be seated gasoline tight.
Poor acceleration may be due to damaged or worn plunger leather in accelerating pump, corrosion in pump cylinder, loose or cracked cylinder, cracked plunger or bent pump arm.
Pump stroke is adjustable for high or low temperatures. Set plunger pin in hole to give longest stroke for cold weather. Set pin in hole giving shorter stroke for hot weather driving.
Throttle valve, bracket and rod assembly
Throttle shaft and lever assembly
Pump cylinder assembly
Throttle shaft dog
Pump arm assembly
Low speed jet tube, size No. 66
Choke cone assembly
Low speed jet assembly (truck only)
Choke cone arm
Multiple jet nozzle, size vertical No. 48
Choker shaft and lever assembly
Body and bowl nut assembly
Tube clamp assembly
Needle seat gasket
Ball check housing
Float and lever assembly
Bowl ring gasket
Tube clamp lock washer
Float lever pin
Body flange lock washer
Needle & seat assembly
Throttle lever adjusting screw
Ball check strainer
Wire clamp screw
Idle adjustment screw
Tube clamp attaching screw
Adjustment screw spring
Pump arm clamp screw
Body flange screw
Throttle valve screw
Tube clamp bolt
Well jet assembly size No. 56 1/2 3 sizes lean
Tube clamp nut
Well jet assembly size No 55 std
Choker shaft cotter pin
Well jet assembly size No. 56 2 sizes lean
Pump jet ball
Well jet gasket
Choke plate washer
Pump jet housing
Pump jet assembly, size No. 76
Plunger shaft pin
Pump jet plug, size No. 76
Connector rod sleeve pin
Gas line nipple