Get a passthrough. Try not to flood the atty ,if it makes a bubbly noise its flooded ,won't make vapor if it is flooded, blow through it backwards to remove excess liquid.Make sure the poly is fluffed up level with the cart.Make sure the threads are clean and making contact by wiping them down with alcohol on a cloth.A lot of people use the 510's ,I use them ,901's and 302's and they all work well,801's are only good for dripping in my opinion but real good for that.