Reading this very informative thread and from my past experience, it seems clear to me these problems manifest from the pump, in that pumps are designed to pump as opposed to suck. This is why motor manufacturers and others fit their pumps in the tanks to get the pump as close to the origin of the fuel as possible, so.

Has anyone considered pressurising the fuel system from the engine, this could be regulated to around 3to4 psi, a very simple regulator could be manufactured to fulfil this requirement, it is something I am considering trying.

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