I usually fly off a stooge, by the time I get the thing started, set securely in the stooge, adjusted, walk out to the handle (I'm beyond running) and get launched I've often already burned a minute's worth--so usually use more like 1 1/4 up to 1 1/2, sometimes even more. Maybe too my.061s are thirstier than most. But for sport flying I'd think an ounce would be plenty.
--Ray