I'd look for anything causing drag on the right wing, could be loose aileron gap tape where the leading edge is forced up under air loads or poorly seated spoiler on the right wing. As noted, right turn has nothing to do with zero ailerons or stick position. If unable to find the cause, a small aluminum trim tab (bent up) placed on the trailing edge of the right aileron will make the aileron fly slightly down and counteract the right turning tendency...........but this remedy will add some drag!
Hope this helps,
JJ