Old John Deere needs help

Hello from Rhody,
Hi everyone, I live in Rhode Island, 40 minutes wide, 60 minutes long.
I have a JD 175 hydro 14 hp Kawasaki. My tractor only runs on choke. I've replaced the fuel filter, fuel pump and the carburetor. It starts right up but after replacing all these parts I'm still having the same problem. Any suggestions?
Thanks