I have a 00 xcsp6000 VES. I don't think the carbs being too clean is the issue.
On this sled, if it gets hot, it will reduce power and bog like hell until it gets cooled down by the heat exchangers. In marginal snow conditions, I need to run in the fresh stuff once in a while or this happens to me, and everyone else with this sled. it should however not die, just run with a lot less power until it cools down.
This sled does have a TPS sensor, is that adjusted properly? If you removed it from the rack when cleaning the carbs, I bet it is out of adjustment, but that still may not be the issue. How long idling does it take to have it bog and die?
Also, how old is the fuel? is it on the regular gas ignition or premium 91 only? I would at least only try to run it on regular ignition setting until the gas is known to be fresh.