[burkbuilds]

I don't know what the weather is like in Portland this time of year, but I've had something similar happen here in colder weather when I was at about 3/4 tank full and changed pitch (going up or downhill) and picked up some condensation (water) from the upper part of the inside of the tank. Same type of issue, lost power and all but after parking in the sun all day it ran fine on the way home. A friend suggested that I needed to keep the tank topped off as much as possible during cooler weather and I never had that problem again. So it does sound to me like you might have had some water in the gas and you probably did the best thing by draining and refilling with new fuel. Also, if you have the choice, non-ethanol fuel is less susceptible to picking up water than the ethanol version plus it has more energy than ethanol mixed fuel.