When i bought my D-50, it had a spare belt. A few weeks later, i took it apart to find that the original belt was completely thrashed. I put on the new one, which is about 3 inches in radius, and i wasnt strong enough to lift it back onto the belt lifter or ffan, and it was very hard to twist the belt lifter. So heres my question: Are you supposed to stretch the new belts before you put them on? If so, how would you do it?