I think a 9x7 three blade prop falls into the sufficient load category. On the edge and close, but okay. I revved the pookies out of my Enya 80-4C and it never had a problem. In fact, it seemed to thrive on high rpms. Climbing knife-edge flight with a Goldberg Anniversary Edition J-3 Cub, for instance. I flew it like this quite often for several years before selling it. Last I heard, the other fellow was flying it the same way several years later. I do not think that I would apply this philosophy to a cheap Chinese four-stroke, but who knows what the results would be? The Enya 80-4C held up just fine.

The problem is that this prop is not going to deliver all that much thrust. Of course, that depends upon the model that you are flying too.

It might be time to consider either putting larger diameter wheels on your model, or replacing the original landing gear and wheels with something that will give you the needed ground clearance.

Good luck.

Ed Cregger