It's always something

[moar_carbz]

I know this is a little late, but check your "float drop." On some floats there's a tab to adjust how far down the floats can drop when you're at high speed. If a float drops too far down, the needle can become cocked in such a way that the float can't easily push it closed again, then you have a flooding problem, which results in gas coming out the boosters. If you pull the float bowl all the way off you can look at the motion of how it opens and closes and see if this could be going on. The floats aren't really supposed to be able to touch the bottom of the float bowl if everything is right because this is what can happen.