Thank for all the advice. So far, I had added a quarter of an ounce to the tail. No good weather for flying right now. Will try that. With that weight it seems to balance near the front line - the up line.
In answer to Charles about weight, I don't have anything to weigh with. I can say, that a good new kit, even an ARF will be lighter than this often repaired porker.
I just finished all the modifications to the 40 FP that I ever plan to do. I just added one head shim. Before that I put a slightly smaller venturi in it. Hopefully, no more, runaways.