Inliners International Forums General Discussion Engines Starter on 51 not working properly

First Hi to the board, this is my first post, though I have been on for a while. Now to the problem
I have a 1951 Chevy 4 door deluxe with the 216. My problem is when I turn over the engine the starter works for one crank then spins freely. I am guessing that something in the solenoid or arm is out of wack but I'm not sure since this is my first early 50's car. Any help in the right direction as to a fix is appreciated!
Aaron