Originally posted by bills30ford
The gas backs up the filler neck I ususally look for a gas nozzle that is vented (small holes) and squeeze the nozzle very easily and sometimes I am OK.

Is there any way to add supplemental tank vents??

if you look at and think about what you just said, you answered you own ? if the gas wont go into the tanks without coming back at you, then the tanks is not properly vented according to the amount of gas you can put in. probably the holes in the baffle are not big enough or no holes in the top of the baffles.