Case DC-4 carb.

I have restored this 1952 DC-4 and she is ready to pop off and run, but to my question, how many rotations out do i need to turn the neadle valve for it to run smootly?

(quoted from post at 00:14:02 03/12/11) I have restored this 1952 DC-4 and she is ready to pop off and run, but to my question, how many rotations out do i need to turn the neadle valve for it to run smootly?

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That's not an exact science, a good starting point would be one turn off its seat for the top small idle screw and 1.5-2 turns off its seat for the lower main jet. After the tractor is running, allow it to warm up a bit and then while running it wide open turn the lower jet in slowly till it starts to stumble and then back out till it runs smooth again, then an additional one half turn, see if it will accelerate without stumbling when the throttle is opened wide open quickly and if so you are ok, if it stumbles try opening it a bit till it accelerates smoothly. After it is set on the bottom jet, the idle speed is the small screw on the throttle shaft, set it at the speed you want it to idle and then set the small top idle mixture screw to the smoothest idle. After this process you may just want to run back over the adjustments as often the adjustment of one will slightly affect the other. I have been working on DC's all my life as Case mechanic and also build puller engines for them. When we farmed I would like to have a dollar for every hour I spent on my 39 DC of which I am presently doing the engine over. They are a great tractor and I sincerely hope you enjoy yours. mEl