RE: To de-fuel or not to de-fuel that is the question
It's good practice to seal the tank when possible after a flying session. I usually try to run the tank out on the last flight, because I don't mine doing dead stick landings. Consider what going into you tank during the flight. Since most fuel tanks are pressurised by the muffler pressure tap, the raw fuel is being contaminated by returned oil and combustion byproducts, one of which is water vapor. So if you pump that mixture back into your main fuel supply, you are slowly degrading the fuel. The only tank that does not do this is the tetra style fuel tank, since the pressure is on the outside of the internal bladder and the fuel remains pure.