just an FYI- my people 50t came with a #70 main carb jet. Way to small, so replaced with i think, a #90 or #92. This did more than anything to resolve hard start/warming up issues. And, it's low budget- but I "choke" by placing thumb in air intake when starting/idling.
far as I know, and I've asked around plenty- no known way to add manual choke, I would love to do that also. Auto choke seems to be largely useless. Good luck...