So I just installed the "adjustable main jet". I adjusted it so the engine ran smooth at W.O.T. and checked the plug. Plug looked dark. Was told to adjust the air screw. Had to use a bendable screw driver and even that was very hard to do. After I adjusted the air screw it ran even better. So I thought, with changing weather conditions I will need to adjust the main jet. While adjusting the main jet I should adjust the air screw. I am thinking about making an adjustable air screw. I seen how the " adjustable main jet" was made and though I can make an adjustable air screw. For those of you who have adjustable main jets, do you have to adjust the air screw?