Acting like one cylinder firing lean.

You need to adjust/center the secondary butterflies so they don't hang up when closing. Idle mixture screws do not have to be the same. Every dual plane engine I've owned needed split jetting to even the burn.
Thanks that totaly makes sense now wit a dual plane manifold. So I take it the secondarys should be completely closed at idle? Been looking for info this morning about it, but no luck. Thanks again