If the engine has only been run twice, it probably isn't broken in yet. If not, and you're trying to completely lean it out, it will usually die. Break in an ABC/ABN engine only SLIGHTLY rich for 4-5 tanks. It should be fine then. Double-check the idle needle to make sure it isn't closed completely. The needles will interact on some engines.

There is no way fuel splashing into the pressure line inside the tank could be choking the engine. There is positive pressure from the muffler to the tank in that line. What's happening is the engine is running too rich to begin with, and the extra pressure caused by connecting the pressure line floods it. Be sure the pressure line is properly connected to the muffler. Check for a clogged pressure line. Be sure the klunk inside the tank is at least 3/8" away from the back wall. Also, if the fuel is splashing that much, you need to pad the tank more.

Dr.1