Cub Cadet 1325 keeps stalling out after a short period of time

I have a Cub Cadet 1325 that keeps stalling out after I use it for a short period of time. It seems like gas isn't getting to the carb. I have cleaned the carb. Replaced the fuel filter and replaced all the rubber lines. I have also tried running it with the gas cap off. When it stalls out there is hardly any gas in the fuel filter. When I let the mower sit for a bit the fuel is in the filter again and I am able to mower for a little while longer. Any suggestions?
Thanks