bryan, could I ask what your jetting is on your 24mm Mikuni? I had mine running perfectly with no bog off the bottom when I crack the throttle open but since it warmed up and I changed my Pushrods (shorter) I got the bog back again. Mind that the temp difference was about 18 degrees hotter when the bog came back. Right now I have the jetting as 20 pilot (2 turns out) 140 main and stock needle at middle clip setting.
If it was running well in colder weather (the air is more dense, and can support burning more fuel) you might try moving the clip on the needle up a notch, which will lower the needle in the jet, and lean the mixture out about 2%, IIRC. I also have a 24mm flatslide, and am also tuning it up, for the warmer weather. I have a bunch of these
carbs, and from what I have seen, the needles all vary widely. I have had the best results slapping a new
carb on and running it, before trying to jet it. A skinny needle might require a 100 jet, where a fat needle might run it's best with a 140 jet. There are way too many variables to jet to a certain size jet and expect perfection! These little motors will make you a really good tuner, though!