netcat snippet equivalent, in F# (TcpClient)

I do this in Unix with the netcat tool:

$ netcat gh05.geekhosters.com 50001
{ "id": 0, "method": "server.version", "params": [ "1.9.5", "0.6" ] }

The result, at the time of writing, is the server replying to me this:

{"id": 0, "result": "1.0"}

Great! Now I want to do the same in F#.

I tried this:

let rec asyncPrintResponse (stream: System.Net.Sockets.NetworkStream) =
    async {
        let response = stream.ReadByte() |> Char.ConvertFromUtf32
        Console.Write(response)
        return! asyncPrintResponse stream
    }

let TcpClientTest() =
    let client = new System.Net.Sockets.TcpClient()
    client.Connect("gh05.geekhosters.com", 50001)

    let stream = client.GetStream()
    let bytes = System.Text.Encoding.UTF32.GetBytes("{ \"id\": 0, \"method\": \"server.version\", \"params\": [ \"1.9.5\", \"0.6\" ] }\n");

    asyncPrintResponse stream |> Async.Start
    stream.Write(bytes, 0, bytes.Length)

    stream.Flush()
    System.Threading.Thread.Sleep(TimeSpan.FromSeconds(60.0))

The above prints, however:

{"error": "bad JSON"}

What am I doing wrong?