John Deere Z225 Zero turn mower wont run without the choke fully on

[crossjohn]

I have a john Deere Z225 zero turn mower. I have put two new carburetors on it. I replaced all gaskets and gas lines. I put a new fuel pump on it, but it will not run without
the choke fully on. When it starts with the choke on and I slide it off choke it shuts off. This thing is driving me crazy. Anyone had any idears?

 

[bertsmobile1]

have you tried it without the air filter ?