My oldie is a craft shop and I’m trying to improve the mix on the weaver. Setup is a 100hp 2.0 OHC Ford engine with 48 IDF Weber carburetors, which I modified however (inlet opening of the trumpets is reduced to 35mm to get a better flow). Moreover, the carburetor does not belong to the engine by default. So I have no default values and I have to adjust everything by Trail & Error. I found a setup that has Lambda values between 0.75 and 0.85. r has constant mixture distribution, no matter whether gas is gone, partial load or full gas. However, the mixture is still about 0.05 to 0.1 too fat for my taste and I would like to make the mixture thinner over the entire speed range around this value – if that is possible. I did not find another nozzle combination that can do so. But during a test drive, the engine was sometimes much leaner than I had mistakenly turned the (at the top of the IDF vertical) jet poles completely pure. On the other hand, the carburettor of course pulls out of the air if the sticks are not really tight. But a buddy said that this was (also) because of the fact that there is of course more air and less fuel in the tubes (less fuel-pillar). If that is so, could it be good to set the swimmers 2-3mm lower? But before I take everything apart now and fluff around the float stands, I wanted to ask the carburettor experts here what the lowering of the fuel-level brings, we nn even?