4 Star 40 engine size?
I've run an LA .40........TT.42GP.......and a Webra .40 on mine........can't see where any more power is needed.......
A friend has one with an old OS .40 4 stroke on it.....flies great.......but the vertical ain't great........
the LA .40 did fine.......as did the GP .42........both ran great for me......and they are both light engines........
Between the 2.......I would go with the GP .42......seems like a much better engine......and a little more power than the LA..........