bought this to fix fuel drain back problem

My ramcharger does this (drains back ...) if I let it set for about 3 to 4 days... how why
But it does........ could it be draining back because of my gas cap,fuel pump or is it draining in back because my float is not seating after the pressure is off of it when I shut the 318 off............ Hay mine does it and this is not new to us and our old carbs and pumps........ I will not run a electric fuel pump... More volts/amps being drew.. plus a manual pump is easy to change and find....... Glad to here it is working for you and I will be looking at getting me one It's not a racing HP engine.... DD and thank you for posting this up trudysduster, Keep us updated but I am sure this will rid you of this loosing prime problem, I know this has been a problem for many old systems like we run..