Just as an FYI, under some circumstances, specifically if you have a pump or regulator in the fuel delivery system, you can simply put the 'T' in fuel supply line. Gas engines, YS engines, some OS 4-strokes, engines outfitted with Perry pumps or Cline regulators can all be T-ed without any problems. Since almost all of my engines are pumped, I normally use the T in the supply line...