In some cases the bigger ifrs/idle bleed combos help as you found out and lately I've been putting in bigger ifr's to help out the idle/transition circuits and to come up on the boosters happier instead of a big lean dip. However, this apply's to some and others may need to be leaner for various reasons but the wide band and plug reading go a long way here and a chassis dyno better yet........
When you add bigger ifrs, what does it do to the idle fuel screws; do you normally have to turn them in some more?
In all my cases,(going lean off idle), the idle mixture screws didn't need adjusted much, if at all. The idle mixture screws can help very little with off idle boggs. They actually control the volume of air/fuel mixture being delivered at idle to the small holes below the throttle blades. The IFR's affect fuel to transition slots. If I'm wrong with this description, I'm sure someone will jump in and correct me.....
