SASless,
The first flight was with the CG located at the 25% station and was moved forward 5% after each attempt. The longitudinal rotation did slow somewhat with each change. Now, I'm looking at the DCP ratio. Maybe, the aft rotor need to move more than the front due to flying in the wash of the front rotor. A ratio change, as you suggested, to say 1/2 might be in order here...it's easy enough to do with a change in the linkage position on the aft bell crank.
Yes, It's great fun doing this. My grandkids love to help on Sundays, after church, by being my "ground crew". They each have a job doing camera work and picking up the pieces, lol. The most enjoyable part is the experimentation. I have made blades with BERPs and even servo flaps...Kaman style. Now, I'm playing with blade twist but it seems to be above my skill set, for the moment.
I will certainly give the Huey fellow a shout. I love to talk "helicopter" with anyone!
joe