This used to happen on my bike ( RD07a '98 ) on high speed cruising (motorway)
1. Riding fast with pretty much throttle
2. Close the throttle -> high vacuum in the inlet manifold
3. Open the throttle somewhat to maintain the speed -> bike feels like stalling for short while (approx. 2 seconds ?)
4. The engine starts to pull again.
I think this is how the AT carbs should work. The are CV model, which means that the slides are controlled by the inlet manifold vacuum, but there is a slight delay on how quickly the slides (and the needles attached to them) are allowed to react to the throttle. The result is that the bike runs on VERY lean mixture for a couple of second or so before the slides adjust (the icarbs momentarily only supply enough fuel for idling while the throttle is already on wide open position).
This is why the Dynojet kit includes a drill bit to drill the slide lift holes (via them the manifold pressure is lead to control the slides). This sharpens the throttle response and is highly recommended. The downside is that the ride can be a bit jerky on lower speeds as the carbs react to throttle almost instantly.
The drill bit with Dynojet kit is 2.5 mm I was told and this was the size I used. I'm very happy with the bike with this mod. The above motorway behaviour is now history.
Yeah, and the fuel pumps still fail, too. I have had a Pierburg electric with VERY low pressure (0.1 bar system, 0.4 bar max static) in place for few months now. Ah, that's another load off my mind when thinking about AT weak spots.
ex. RD07A '98 (missing it now), Suzuki V-Strom 1000 K3 (chuddering beast)