Remove the inner plastic fuel vent neck liner.
Inside the neck of the fuel vent hose, you can see a tube which lines the inside. This liner tube is made of hard plastic. It’s about 9.75" long and reaches about 7" into the tank. Gas can not be filled beyond the bottom of this tube. Shortening it will increase the volume of gas that will fit into the tank.
To remove it, you will need to pry it away from the sides with a small screwdriver and grab it with any small tool that offers a STRONG grip. I recommend a needle-nose vise grip because this tube is crammed in there TIGHT. In fact, removing this tube was the hardest task on this project. Some people removed this tube in sections by pulling out 3", then cutting it off, and pulling another 3" until the tube was completely removed.
NOTE: After the liner tube is fully removed, you must have at least one piece of it that is 3" long to be reinserted.
