Thanks Dave,
I calculated the flight system weight of the Predator 30-8 with the 14 cell pack to be about 12 pounds.
The output is 8912 watts to the prop=11.94hp (48volt x 211amps listed =10128 watts input x .88% efficiency = 11.94hp at prop)
That is a 1 pound per horsepower rating. Thats good.
But this two-stroke gas engine weighs 7.96 pounds and 16.5hp = .48 pounds per horsepower. The fuel weight is not significant.
http://www.desertaircraft.com/engine...hp?Page=DA-150
slowrotor