First I want to thank you all for the ideas to make me think in another direction and Im not gonna say that box thing.
I found the tab on the lower cowling which slides over the radiator in a KF-7 had somehow become weak and was not fitting as firm as it did in the beginning. I had put rubber tape under it but the fit had loosened to the point where it ratteled againsed the radiator. I am going to add a peice of fiberglass to the tab and put a thicker peice of rubber in between. It was scary but the Rotax is still running great.

thanks again for all of your input

Rich