Not sure if you came across this topic http://www.utvboard.com/topic/1423-power-loss/page__hl__%2Bloss+%2Bof+%2Bpower__fromsearch__1 but it sounds like the problems you are having is very close to the same as what i was having. I checked everthing and like you pulled the tank a couple times as well as new fuel filter,air filter fuel lines regulator, checked all wire connections and finally replaced the computer and have not had the issue since.Too bad your not close to someone with a trooper to switch them out just to see if that is it.