A nose-heavy airplane produces MORE line tension*. Might try removing the tail weight and trying it. Don't worry to much about the CG for the moment. This will mostly just slow down the control response. You can deal more with that going forward. Adding tail weight is usually a bad sign. Try it without first. Then you can work the engine and tank back further, use lighter wheels, increase handle line spacing or other means to improve the turn rate if you want too.
Dave
* In level flight and below about 60 degrees of elevation. It starts working against you above that. I don't think we are worrying about vertical maneuvers in this case.