With my limited computer skills, I can't keep in my head how to post a link; don't laugh, I earned my memory lapse. If you take off the carb and look down the open rotating venturi drum, you will see the little brass rod running across the opening. The slit in that rod needs to be facing straight down the venturi regardless of altitude you are flying at. Now, with the engine running, if you transition the throttle up and small droplets of fuel seem to dance out of the carb, your bottom end needle is too rich. If you transition up and the engine sags and maybe dies in the throttle up without the fuel popping out of the carb, your bottom is too lean. Do turn in two maybe three clicks at the most before trying the fireup again. You will need to click the top end needle out as many clicks as you click the bottom end in since they work inversely proportional to each other. If you are holding the carb in your hand, you might be able to see the bottom end needle in the slit since it has a blunt end; the top end is tapered to a needle point. I apologize here for the wordiness, there are some very good links to ST tuning nomenclature out there. I have run these guys since around 1980 and I recognize they weren't ever meant for easy tuning, but they do run very well when you find the sweet spot; just demanding patience from you, I hear you.