I was a life long nonbeliever up until last week; I never thought in-flight tank height was as important as people preached. I've been flying classic pattern lately with a pumped, piped ST60x on my Tiporare (with a high tank). I think we can all agree tank position is not an issue on a pumped motor. But last weekend I unpumped it while trying a new carb. MISTAKE. I flew two rounds with it and both times my caller had to set the needle way rich to keep it from sagging when held nose high. In flight it never did lean out until I did my first inverted pass. BAM! As soon as it unloaded it went lean, got on the pipe and was screaming! The peanut gallery joked that I should complete all my passes inverted. It's the only way it would run.