Open the top end to a rich setting, then close the bottom end needle, then open it maybe 2 turns or so and start from there.
Hold the car in your hand while giving it gas, you should be able to tell the difference when you lean it or richen it.
Make sure you are getting some good smoke out the pipe.

YOu will have to mess with it for a while to get it right, keep in mind that needle changes take a minute to take effect. This is where a lot of people make mistakes and end up feeling like they can never get it right. I guess a lot of people new to these engines expect needle changes to happen as the needle is turned.
This is not the case, make an adjustment then run it for a bit, then make another adjustment, run some more.

Once you get the bottom set, leave it alone, make adjustsments with the top end needle.