Packard Forum Index » Pre-War (1899-1942)

I have opened the spark plug gap to 30. That eliminated much of the black exhaust smoke. At the lowest idle, engine is smooth. At high idle or revved up the engine is definitely missing consistently intermittent. Black smoke is then at a minimum, but still present.
Note: My carburetor is NOT the same as the carburetor on page 212 of the 1922-28 Service Manual.
1. Observe the Allen screw adjustment at the bottom in the center. Which way should I turn to adjust for leaner mixture, in or out?
The ONLY other adjustment to this carburetor is the fuel float. Which way to adjust the float for a leaner mixture?
Note that there are no other adjustments to this carburetor except to remove the air valve cover or remove the float chamber top.
Steve the exasperated

Does it look old & decrepit? It should, it turns 98 in January
[PROCESSING IMAGE.... PLEASE WAIT]

You have to make sure your air intake is set correctly as well. The gap when the engine is off is 5/32" (i believe). If you do not have that opening your will run too rich.

Screw in(clock wise) to lean a mixture.

Gar

Hi,
I have that same updraft carburetor on my 1929. The Allen screw you mention at the base of the carburetor is not an adjustment. It is a set screw that goes through the carburetor wall and anchors the copper jet in place. It doesn't do anything to change air or fuel mixtures. There is another adjustment you can make, but it is to the float pin inside the bowl on the left. The float pin (you can see the tip of it under that hex nut in the middle of the "Packard" plate if you unscrew it) actually drops down as the float rises in that bowl and eventually shuts off the flow of gas entering the float bowl. The pin is adjusted by taking the whole float assembly apart, heating the brass collar where the pin contacts the float mechanism until the solder melts and moving the collar a very small amount. By changing the location of the collar, the float pin shuts off the gas flow earlier, thus modifying the amount of gas entering the carburetor. PM me if you want the Packard information on doing this procedure, but it is not a simple thing to do...the first time.