Humm, ok I see now.
I see you've also looked for air leaks. Your stock pipe is completely useless? I mean you can't even connect it at all?
Are you using the stock variator?
You said it wont idle when cold. When this happens, what happens when you use the choke on it and it's cold? Does it idle then?
And thanks, my Si rips! My set up is similar to yours, 13.13 carb and hi flow filter, giannelli pipe, olympia variator, malossi belt and stiffer rear clutch springs.(edited)