Takeoff hesitation can be eliminated and acceleration out of a turn can be improved by simply re-routing your fuel line. No Bull—it really works. This applies to standard tank without pump set-ups. What you do is route your motor's fuel line around the right side of the motor, over the front bearing housing in front of the carburetor, and back, then loop· it up to the fuel nipple. The reason that it works is that during acceleration the fuel wants to move back, creating a pressure reduction or total cavitation at the jet in the usual set-ups. By routing the fuel line around the front of the carburetor, the fuel to the left of the foremost point is pushed toward the carburetor, not toward the tank. It is the small amount of fuel in this section of fuel line that keeps feeding the motor for the two or three seconds of severe acceleration.
Extracted from a Fox Manufacturing infomercial, Model Airplane News, January 1989, p77.