Did you just get these from Ebay, for about $100 a pair? I've seen a bunch there lately. I don't believe you can just hook them to a power supply and get them to work. Buy a Xylotex board and they'll work just fine. http://www.xylotex.com. I've got the 253 oz-in motors with the same amp rating as yours and they work fine with the Xylotex.