Sticking throttle cable

I installed a brand new Carter YF 1 bbl on my slant 6. My gas pedal sticks when you first push it down.Get past the sticking point it works great. I thought maybe I damaged the cable somehow so I installed a new cable.Same issue with it sticking. It's hard to push at first push it harder and you feel it stick then after that point it is ok. So I held the carb open a little bit then my son stepped on the gas pedal it worked fine. It just sticks at first. With everything disconnect cable moves freely and the carb linkage move freely. I am lost it should be a simple fix . Anyone have any ideas ?