I want to reiterate the only correct way to do a canard fuel
system is follow the Ruttan plans. To do other wise is risking
your life. Reproduced here in gif form.

<snips>

Paul Lamar

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Lots of EZ's flying with sumps and no fuel selectors... latest trend is
single point refueling...

Wouldn't a system that is capable of single point refueling, also be
capable of taking return fuel in either tank?

What is wrong with my logic here?

tc

The problem is there are no plans published for "sumps and no fuel
selectors". There can be a wide variation in "sumps" and some of them
may not work. One needs a detailed drawing of a sump system including
all details on vents and plumbing that has been extensively tested
under all possible conditions before one adopts it. It is best to follow
Rutans plans to  the letter. Fuel system are very subtle and deceptively
simple. One must take into considerations the exact pressures in the tanks
under all scenarios. No one to my knowledge has documented the pressures
in the tanks when they deviate from the plans. You really need to
understand the entire fuel system in great detail.

Paul Lamar