When you increase the size of the IFR, you usually have to increase the size of the low speed bleeds proportionately to maintain the correct part throttle A/F ratio.

Sometimes when you increase the the LSB you have to go back and increase the IFR a little more, but not always.

 

Where are these low speed bleeds? And what's the procedure for checking them? maybe one day I will be able to understand all of this it seems like ever time I tinker with it I learn something new.

 

The LSB or low speed bleeds are also called the "idle air bleeds" as depicted in this photo:

 

Will this effect only really light throttle? It seems that it runs around 14.1-15.1 the rest of the time I was afraid if I opened up the idle air bleeds It would defeat the purpose of drilling the IFRs. And I need to bump my idle up I have the blades set at so the idle transition slot is showing .020 and its wanting to idle around 450-550rpm in gear, do I need to drill the blades?

 

Add a touch more idle timing to get your idle speed up. Keeping the slots at 20 thou seems to really help overall manners.

The IFR is like the main jet for the low speed circuits. It is my understanding air bleeds keep the mixture from getting progressively richer as air flow (RPM) increases. The idle circuit is for just off idle to approximately 2-3 thousand RPM. My approach is to set the IFR to get the AFR just off idle, than tweak the bleed to adjust the AFR up or down at the top of the idle RPM band just before the main circuits take over.

And like someone said the idle air screws are for idle only.