HO Heavy 4-6-2 w/DCC& Paragon 3, Undecorated

I purchased two different 4-6-2 locomotives, this one and a Santa Fe. Both are DCC equipped and compatible with DC. The Santa Fe functions smoothly at any speed. This locomotive only runs fast, too fast. I've tried it with separate layouts with the same result. To get it running, you have to start the throttle at the 3 o'clock position (three-quarters full). When you try to slow it down, it comes to a complete stop and you have to start the process all over.