When choosing a model airplane propeller you must keep in mind that you are choosing the propeller based on how you want the airplane to fly. This really has nothing to do with the engine other than the fact that you must stay within the recommended window of props to prevent damaging it. The same engine used on two different airplanes may be using completely different propellers. If you have an airplane with low drag designed for speed then you will want more pitch. If you have a slow airplane with a lot of drag, such as a bi-plane, you will want more diameter (thrust) and less pitch (speed).

[link=http://www.hooked-on-rc-airplanes.com/model-airplane-propellers.html]choosing the right size propeller for your airplane[/link]