I'm more than a little surprised at the lack of attention to this spreadsheet. Maybe I have it all wrong, if so, let me know. In all the 2 cycle carburetors the low-speed and high-speed are pretty much interchangeable except for the scale of change with each needle. I can't imagine the 4 cycle carbs being much different, maybe I'm wrong. In this particular spreadsheet, I've made the low-speed one size smaller and the low-speed 2 sizes bigger. As you can see, the overall increase in flow is .5%. It could just as easily be any other number just by changing the Standard jets.