I agree - sounds like someone mixed and mismatched parts. They used a bowl from a larger bore TSX-??? carb and stuck the choke plate from the smaller -245 into it. (I'll bet you'll find it's got the wrong (larger) venturi ring in it too.)
My recommendation would be to relegate this "mongrel TSX-245" to your parts collection and replace it with one of your other TSX-245's.