Project Speedbox SE and Planer 2

I was hoping someone could assist me with figuring out how I can use the Project Speedbox SE with a turntable I built which uses the REga Planer 2 upgrade motor which is essentially a Premotec 31813. I've tried connecting it up to the box but don't seem to be getting enough juice to spin the platter at the right speed. There's a site that indicates that the speedbox should work fine with the P2.

Any help would be greatly appreciated.