Zero Turn Mower. I'm stumped.

Hey Rusty does it have a fuel cut off solenoid on the carb bowl? If so that’s most likely your problem they will sometimes fail and let a little fuel in and of course when you choke it you restrict the air intake to match the low fuel supply so it runs but not well. Make sure it has a good 12 volt supply going to the fuel cut off solenoid as well.
Had this same thing happen to mine. Ended up cutting plunger to fix problem. Caused same problem your having Rusty!