This tip was written by Paul Sponseller, Glasair I RG.
I was happily flying along, intending to burn most of the fuel from my main wing tank in order to change a dripping fuel sump drain, when the engine suddenly quit. I thought I should still have had nearly two gallons in the tank. That incident started me thinking, and that can get dangerous.
The figure below shows how I intend to modify my fuel system. With this option, the pilot can still select which tank to use first, but the system would primarily be used by leaving the fuel selector on the header tank at all times. Since all fuel is fed to the engine from the header tank, there is no danger of the engine quitting when the main tank goes dry. This would be a real advantage if you have an injected engine and want to squeeze all the range you can from your fuel aboard.