It's been a few years, but I had that problem on my DP-250 too. The pulley itself isn't bad. It's just a small manufacturing defect that's easily corrected.
If I remember correctly, there is a hole for a roll pin that was drilled slightly too large, allowing the roll pin to fall out. I went to the next size larger roll pin and drilled the hole out to the proper size to fit it. The pulley just needs to be re-assembled. In the correct orientation the fingers of each half of the pulley fit together like a box joint. The spring is there to hold them together until you adjust the speed higher. The belt tension will force the halves of this pulley to spread apart as needed when the pulley at the spindle end closes up by the speed change adjustment. I'll try to look at it again today to refresh my memory and will add to this post if I see anything else that may help.
Central North Carolina
Last edited by CharleyL; 04-28-2014 at 09:28 AM.