Oppama pulse engine tachometer

Hi,trying to set carb with one of these idle is no problem but high revs it wont give me a steady reading.I have tried with and without the cable.The instructions I have mention using the mode and set buttons depending on engine type and cylinder number.Now in the instructions when you press the set button you should use the chart down below for your particular engine.When I press the set button I can only get 01,02,03 or 04.Can anyone help with this please or does anyone know of a video of "setting" this taco not just holding it beside the chainsaw.