"One-way" fuel line valve..?

Interesting primer-booster solution.
But is there any risk that the not-running electric pump does block the gazoline coming from the mechanical pump?

Maybe a parallel installation of both pumps (using "Y" connectors) would be better than a serial installation?

Something like that :
View attachment 1716161295

What do you think about?
Just use a rotary vane pump that the fuel can flow through.