Carb needle and Seat help

I have a 1976 with the tank under the seat and a lift pump. The pump overflows the needle and seat and loads up the tractor till she stalls. I remote mounted a tank on the hood and the engine runs fine without the pump. So I know the pump is stronger than the needle and seat. So where can I get a new needle and seat?

Thanks

SHmity

Have you checked for a sinking float? Another culprit can be a piece of flotsom in the needle seat preventing proper seating of the needle. I also have had sticking foam float problems with my SS 16 and a metal replacement float was the solution.