""Is there a lean spike when you tip the throttle in?"" When I had the .075 IAB's and my metering screws were not dialed in, the answer was yes. The 071's (MS dialed in) and the 067's did not show a lean spike at tip in. The light accel from a stop and cruise to light accel both showed 13.8-14.0 on the guage with the red/037 primary pump setup.
""Is there surging/missing at steady cruise below 2700rpms?"" 30mph [1700rpms] (.067"=16 / .071"=16.6) there was a slight surge. 40mph [2200rpms] (.067"=16 / .071"=16) there was a slight surge. 50mph [2500rpms] (.067"=15.6 / .071"=15.6) there was no surge felt. It seemed that once the cruise was richer than 15.6 or so, there was no surge at any rpm level. It appears that 15.6 might be my lean limit.
My thoughts are to test .031" IFR's front/back and go back to the .071" IAB's (stock for my carb) and see where the readings go. Note: I need the gauge to read about 5-7% richer between 1700rpms and 2700rpms. If I swap out the .028 IFR's to the .031 IFR's, that will give me about 10% more fuel available in the transition circuit.
I called QF and they suggest that I do not go richer than .067" on the IAB's with a gasoline setup. So my current IAB's are .067,.071,.073, and .075 IAB's. I will also have the current .028 IFR's, plus .031 and .033 IFR's to test with. The next five days show storms, so I won't be able to give any updates for a while. This will give me some time to get the lost .031 IFR's on order.
Since I am going to have the front metering block off, I am thinking of swapping out the 66 jets for some 65's since my reading at 60mph (3100rpms) is down around 14.2 and it goes lower at 65mph (3300rpms) to 13.8.
