Thank you very much for your suggestions. I will try all of the above and see if there is something out of alignment.

I looked at the propeller last night--it is one that folds back when power is not applied--and it looks as though one side may be reaching out a little farther than the other. If that's the case, I'm sure this would produce thrust problems. I am going to replace the propeller, make the measurements some of you have suggested and then give her another try.

Thanks again for the very helpful suggestions.

Carl.