I have an '08 Ultra, stock with 18k miles on it. In the last week a couple times when I first start the bike there is little to no throttle response but it idles normally. Today, as I was pulling away from a stop sign not too far from the house it happened again. Top rpm I could get to in 1st gear was just under 2000 rpm. I stopped the bike, turned it off and restarted and it ran fine again. The bike ran flawlessly on a 700 mile road trip last week. I did hand wash the bike when I got home.

Any ideas of the culprit or where to start checking?