RE: Welcome to Club SAITO !
If the tank is properly vented, it will not force fuel into the carb. Now, if you only have two lines coming out of the tank, one for pressure (muffler) and one for the carb, yes, it will flood because the tank will pressurize as you fill it through the muffler line. You can use the carb line to fill, if accessible, and the muffler line becomes the vent if it is plumbed to the top forward part of the tank. I assumed that you had a three line system, whereas the tank has a fill line, pressure line and a carb line. The fill line must be plugged after filling so that the muffler will work as intended.
Bob