I have a U Can Do thats hard to spin, It's easier inverted though.
I cut throttle, point nose down, 2 turns w/ Left aileron, hit a blender, SLLLOOOOOOWLY cross right & down with right stick while rolling up on throttle.

I should mention I fly this plane with full deflection, VERY tail heavy, and little expo.
There is a "sweet spot" on my right stick in the upper right corner that I MUST hit to get it to spin. To little deflection, and she spin/dives lamely down. To much and it will either spin/waterfall/spin/etc or simply stop all together. But when it's done right MAN DOSE SHE EVER!!!! She gets FLAT, and with careful throttle management she'll start climbing. What a treat!!

Good luck!!
hope you get it figured.
p.s. Check your CG 1st!!! nose heavy dosen't help at all.