Michael - the method I use for setting the idle on any vehicle is quite simple (although at first blush it sounds confusing).
(1) I look up the original manufacturer's RANGE for the idle adjustment. A common range is 3/4 turn to 1 1/2 turns.
(2) I divide this range into thirds. In the above example, one would have 3/4 turn, 1 turn, 1 1/4 turn, and 1 1/2 turn.
(3) How I set the idle depends on the condition of the engine.
(3A) New engine to maybe 500 miles - set idle out 2/3 of the range (in our example 1 1/4 turns).
(3B) Engine broken in, and in good condition - set idle out 1/3 of the range (in our example 1 turn).
(3C) Engine worn out, burns oil, etc - set idle out the full range (in our example 1 1/2 turns).
(4) Once I have set the idle mixture, I start the engine, run at a fast idle until the thermostat opens, and then set the idle RPM with the throttle positioner screw.
Gocart - you are describing a fuel delivery system issue, among other possible issues. Check your fuel pump, fuel filter, tank vent, etc.
And all of the above assumes the carb linkage was checked for wear during the rebuild, and the idle tube was enlarged at the top for sealing purposes.
And if you live in an area where ethanol is served at the pump, the engine MAY be lean. As a test, raise the float 1/16 inch. If the problems go away, you will need to recalibrate the carb for the ethanol, and then reset the float (you don't want to leave it too high, the high setting is just for the test).
And hopefully, you at least looked at this article prior to rebuilding your W-1:
http://www.thecarburetorshop.com/CarterChevroletW1.htmJon.
