Hi Carl,

Typically, the stated weight on a glow-powered plane is dry (or without fuel) unless stated otherwise. You should add 8oz for a plane that size when the tank is full. The game-playing specsmanship can often be confusing.

A Cub design lends itself to require less power for flight. However, you should keep in mind that water take-offs will require more power than ground take-offs. This looks like your Hangar 9 80" Cub at Horizon Hobby [link=http://www.horizonhobby.com/Shop/ByCategory/Product/Default.aspx?ProdID=HAN1500]here[/link].

The Graupner 700 BB motor geared 2:1 looks like a good brushed candidate. With a flying weight of about 6lbs, your 500 watt geared Speed 700 motor will provide around 83w/lb which should work fine.

Good luck!