I use the tee. Works great. There is a pop-off pressure in most walbro carbs. You need I think 6-10 lbs of pressure to open. You can just gavity feed from your gas can by holding can above plane about 2 feet. When gas flows out your overflo, tank is full. You can also plug in a little tank to catch the over flow. That way you do not kill grass or waste fuel Thanks Captin John