Originally Posted by dereknc
When I was a young kid I had the exact same problem with a single speed Huffy. I'm assuming you've got a coaster brake hub. You might try taking it apart and cleaning and lubing it. It's probably just gummed up and sticking. If I remember correctly there's not too many parts inside the hub but I never got mine fixed. I was only 6 years old.
When I took my Schwinn coaster single speed apart when I was a kid there were about a hundred parts. Would have never got it back together without the help of my motorcycle riding neighbor.