[AT] Zenith Carb Adjustments

[Ben Wagner]

I have an old Zenith carburetor on my 1945 Farmall A.  It needs to be
adjusted, since I don't think I'm getting a good mixture.  I see two
adjustments on the carb; one next to the intake on the manifold with a
spring, and another below the bowl.  I've adjusted myriads of small engine
carbs, but never a carb on a tractor.  I think the screw with the spring
near the intake manifold is the idle mixture, right?  I also think the
adjustment below the bowl, a little thumb screw, is the main jet mixture
screw.  I rebuilt the carb about a year ago, and I remember the adjustment
under the bowl having a long point.  If I am thinking correctly, turning the
screw in will allow less fuel, and turning out will allow more fuel.

The engine runs like it has too much choke, smoking and gasping.  The choke
is in as far as possible, so I think the adjustment with the jet will allow
me to adjust the mixture.  Am I correct?  Do I have any other options to
adjust the carb?

Thanks!

Ben Wagner