Bruce,
The reason that you should not tie into the generator fuel return for a fuel supply source is that the return line does not terminate at the same level in the tank as the generator supply line, but it terminates close to the top of the tank, so if you used it as a supply source, you would just draw air instead of fuel.
There is a different modification to the fuel system that many Hurricane owners have done to solve the problem of occasional air in the fuel causing a flame out. That is to install a fuel return hose to the system. To do this, you install a 1/32 inch orifice or smaller in the fuel air bleed hose and run it to the generator fuel return hose. Then you open the air bleed valve and leave it open so that a small amount of fuel along with any air will be returned to the tank, giving the Hurricane an air free fuel source.
Gerald