Do you use that prop on a Venus?
Here is the current TH listing: [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXBMZ5&P=7]Venus 40[/link] Note: It is in the wrong category.
I've got the Tracer which is a very similar design. i.e. this is more like a pattern plane and is not a 3D plane. As such, I don't think the 14x4 would be a good prop for this plane, you might also have ground clearance problems...