Help with idle rpm and carb on 340

Ok I understand initial timing, I have a digital toming light, at idle it says I'm 34 deg, I rev it up to 3500 and still stays at 34 deg. My light I is digital so I dial in untill marks at zero, when I do this it says 34 idle or higher doesnt matter. Now if I pull the trigger (which is supposed to make it like an old gun) my marks are jumping all over the place. What now?