ORIGINAL: coolbean
The silicone fuel line in the tank should be VERY flexible.. When you put your plane in a nose down attitude, the klunk (the metal piece at the end of the line) should fall to the front of the tank.
Uh-Oh....
I made this assersion once in another thread only to be lamblasted by a bunch of people.
Here it comes! DUCK!
But this is how I've purposely set up my tanks and it works very well.