Let me confirm the popcycle sticks under the trailing edge, that Ed Moorman suggested.
It was on my LT-40 that Ed & I were flying, that had the same climbing problem. He said to add the sticks....which adds a negative (or reduces the positive) incidence to the wing and reduces the climb tendency. You may even have to add another stick depending on the CG. A little nose heavy is a good thing ! Now I had a manageable airplane.

Try it, You'll like it !

Ugo