I had a Senior Falcon that took off from grass easily and did outside loops on an OS 40 FP. It weighed 5 1/4 lbs and balanced at the rear end of the CG range, which worked just fine. Absolutely delightful airplane (see my gallery).

Try removing some of that lead and getting the CG back. I bet the modern plans show a very conservative CG. I just checked my log book and I had it at 4 1/2 inches from the LE. If your CG is ahead of that, then moving it back will not only decrease weight, but make the plane aerodynamically more efficient.

Also, 6 inches of prop pitch is too much. If your engine will swing an 11x6 prop, then it will also swing a 12x4, which will give much more thrust on a big, slow flying airplane.

I assume you're using light weight foam wheels, right? Do everything you can do to keep down weight.

Jim