Funny, I was just looking to see if anyone had problems with their heavy breather and not sure what mine is due to albeit a sportster. The other day i was in the rain and the bike was obviously sucking in some water. At one point when pulling out from a red light the bike shut off. Wouldn't restart until after the rain stopped. Then it was fine. This was in a downpour.
Not sure if it's electrical or intake related, but I'm thinking about going back to the ham can and seeing if that works better.
I have a rain sock in the tour pack, but have been through some frog stranglers and not had an issue without it. The Ultra may deflect more rain away from intake, can't say for sure.