what prop is best to use on a 91fx on a razor yak.i have 3 apc props from a 14x4x,15x4w,and a 16x4w,test flew it with a 15x4w and it was pretty good,need a bigger tank than what comes with the arf as it only gives 3 to 4 min af flight time.was gonna try the 16x4w but figured i would ask as i think it might be too big for the engine i know the 14x4w will work