Bostonba, the tank needs to be in one of two configurations, A two line where the clunk feeds the carb and the "vent" is used for presure from the muffler. This is the most common on smaller size planes and what I use mostly.

The other is athree line setup where you have a vent line seperate from the muffler pressure line and you use the vent for a fill. Depending on the engine, you will plug or leave this line open The differece here is whether the engine is a pump engine or not. If it is a pumper, not a Y.S Pumper, then you leave the vent line open when flying.

All that sounds confusing and doesn't apply to your setup.. Make sure your tank is setup so the center line of the tank is even with the spray bar of the carb. Ipull the line off the carb and fill through that line. I also pull the line off the muffler and route it back to the jug. That way, I minimsize the pick up of moist air into the tank. You can just put a catch pan under the muffler and when fuel flowns out of the muffler, your tank is full.When you see fuel going back to the jug from the vent line, with my setup,or exiting the muffelerinto the catch pan witth the other, reverse the pump for a crank or twofor amanual pump or a secnd or so for an electric. Pug your lines back to the carb and muffleif you removed it and you are ready togo

The fuel dot is just a"T" fitting that goes into the carb line. You may flood theengineusing this setup if itisn't apumper.IF youuse the three line setup, you can pump until the fuel comes out of the muffler and then plug the dot line. Again,this setup may flood the carb when fueling.

The two line setup is the simplest and less likely to cause you problems when startingout.

Don