Remember that you must go about prop selection very differently when it comes to electric engines.

The prop size on an electric, will determine how much effective power you'll get out of the engine, how much flight time you get, and how your plane will fly.

Balancing all of this out, is the cause for numerous discussions in the electric forums.

There are on-line calculators available that permit you to come up with appropriate combos.

Too large a prop can burn out your ESC or motor. Too small a prop may result in an unflyable plane, etc.