If you look at that setup in his diagram the loop setup feeds the extra fuel from the carb back into the feed to the pump. I thougt that was a mistake so I called Perry just to ask that question. He said that diagram was for RC Cars and not RC Airplanes. Perry said the loop on airplanes goes back from the carb and into the fill line for the tank. This made more since to me so that is how I have set mine up. I was hoping to hear from someone else who is successfully running the perry pump with a 90 two stroke and see how thiers was setup