[DarrinMunter]

There is a coil inside the motor to prevent electrical noise. That coil is only good to handle about 500mA worth of DC current. With the way were using them, we are easily exceeding that current rate of that little guy. Therefore it goes up in smoke, burning itself open. The motor wires themselves are heavy enough to handle that power, or at least the 3-4 second runs they have to go through.

Mouser has a 3.9uH that has a current rating of 640mA made by Bourns.
I don't have the part number now, I have it at work. - and its pretty close to the same size as the orignal part. Only major difference is instead of the body being green this one is blue - but the color bands are all the same.