After renewing fuel sender in tank the fuel Syphons back to the tank after a few days, so I have to suck it up manually , which is a pain. So I decided to install an electric one, so can I pipe through the existing mechanical one or will I need to go direct to the carb..Only I was thinking maybe I could put a switch on it to turn it off once it has started and the Manuel pump could take over and save the electric pump.