Most of these adjustments require that measurements be made in thousandths of an inch, using some sort of gauge. Drill bits are ideal for this purpose.Model 1945
The model 1945 carburetor is a concentric downdraft single-barrel carburetor with an internal float bowl which completely surrounds the venturi. The unit uses dual nitrophyl floats which permit operation at extreme angles. It is used on six-cylinder engines.FLOAT LEVEL
- Remove the float bowl cover and invert the bowl. Hold the retaining spring in place.
- Place a straightedge across the surface of the bowl. It should just clear the toes of the floats by the specified measurement.
- If adjustment is necessary, bend the float tang to obtain the correct adjustment.
- Remove the air cleaner and disconnect the vacuum lines to the heated air control and the OSAC (Orifice Spark Advance Control) valve. If there is no OSAC valve, disconnect the hose to the distributor and the EGR hose. Cap all carburetor vacuum fittings.
- With the engine off, transmission in Neutral and the parking brake set, open the throttle and close the choke.
- Close the throttle. This will place the fast idle speed screw on the highest step.
- Move the fast idle cam until the screw drops to the second highest speed step.
- Start the engine and stabilize the engine speed. Rotate the idle speed screw to obtain the specified setting.
- Hold the throttle valves wide-open and insert the specified gauge between the upper edge of the choke valve and the inner wall of the air horn.
- Place slight pressure against the control lever and attempt to remove the gauge. There should be a slight drag as the gauge is being withdrawn. If adjustment is necessary, bend the unloader tang on the throttle lever until the correct opening has been obtained.
The model 2245 carburetor is a two-barrel unit used on 360 cubic inch engines. The carburetor uses four fuel metering systems. The Idle and Idle Enrichment System provides the correct mixture for idle and low-speed performance; the Accelerator Pump System furnishes additional fuel during acceleration; the Main Metering System gives an economical mixture for normal cruising conditions; and the Power Enrichment System enriches the mixture when high power output is desired.FLOAT LEVEL
- Invert the air horn so that the weight of the float is forcing the metering needle against its seat.
- Measure the distance from the top of the float and the float stop. The clearance should be the same as given in the "Specifications" chart. Make certain that the gauge is level when making the measurement.
- If adjustment is necessary, bend the float adjusting tab toward or away from the needle. A narrow-bladed screwdriver may be used to bend the tab.
- Check the float drop by holding the air horn upright. The bottom edge of the float should be parallel to the underside of the air horn. If an adjustment is necessary, bend the tang on the float arm.
- Position the fast idle speed adjusting screw on the second highest notch on the fast idle cam. Move the choke valve toward the closed position by applying light pressure on the choke shaft lever.
- Insert the correct gauge between the top of the choke valve and the wall of the air horn. An adjustment will be necessary if there is not a slight drag when the gauge is removed.
- If an adjustment is necessary, bend the fast idle connector rod at the angle.
- The adjustment must be made with some type of vacuum source. If the adjustment is made with the engine running, disconnect the fast idle linkage to allow the choke to close to the kick position with the engine at curb idle. If an auxiliary vacuum source is to be used, open the throttle valves and move the choke to the closed position. Release the throttle first and then the choke.
- If an auxiliary vacuum source is used, disconnect the vacuum hose from the carburetor and connect it to the hose from the vacuum supply with a small length of extra hose. Apply a vacuum of 15 in. or more of mercury.
- Insert the correct gauge (see "Specifications" chart) between the top of the choke valve and the wall of the air horn. Apply pressure to the choke rod without distorting the diaphragm link. The cylindrical stem of the diaphragm will extend as the internal spring is compressed. This spring must be fully compressed for proper measurement of the vacuum kick adjustment.
- If a slight drag is not felt when the gauge is removed, adjustment is necessary. Adjust the diaphragm link to obtain the correct choke valve opening. Adjustments can be made by carefully opening or closing the U-bend in the link.
- Connect the vacuum hose to the correct carburetor fitting. Replace the linkage.
- Make the following check. With no vacuum source attached to the diaphragm, the choke valve should move freely between open and closed positions. If the movement is not free, examine the linkage for misalignment or interferences caused by the bending operation.
- Place the throttle valves in the wide-open position and insert the proper gauge between the upper edge of the choke valve and the inner wall of the air horn.
- While holding pressure on the shaft lever, a slight drag should be felt as the gauge is removed.
- If an adjustment is necessary, bend the unloader tang on the throttle lever.
- Back off the curb idle adjusting screw and open the choke valve so that the fast idle cam allows the throttle valves to be completely seated in their bores.
Make certain that the pump connector rod is placed in the correct slot of the accelerator pump rocker arm. On manual transmission models, it is the first slot next to the retaining nut.
- Close the throttle valves and measure the distance from the top of the air horn to the end of the plunger shaft. See "Specifications" chart.
- If adjustment is needed, bend the pump operating rod at its loop.