Ok, going to trash the Gen6 Fuel pump doggy style on the sea pump design. Got some new Aeromotive Marine 11212 pumps. 90gph/7psi. I want to mount them after the fuel shut off valve before the water separator. Is there any concern on doing this vs after the separator? My thoughts are: valve-filter-pump-separator- carb.
All inputs appreciated.

I go selector valve - separator - pump - filter - engine

I figured might as well protect the pump from water as well, perhaps filter type matters. I have an FST500

They will be fine the way you described

The tech at Weldon told me to always pull through the filter. Why potentially feed your pump what the filter might catch?

Thanks. Brad.

Agreed, I also had it in my head that the pump will work harder trying to push fuel through the filter vs. Pulling it.

Are you having trouble with the old pumps? Are you running more HP than they can keep up with? They seem pretty reliable with very little maintenance. You have the right sequence for install. I looked it up. From what I have seen (on car shows) is that electric pumps hate to suck especially through any restrictions other than the 100 micron pre filter they recommend. In a boat installation even though you may mount the pump in the bottom of the boat it still has to draw (suck) fuel from the bottom of the tank up to the top of the tank and out. Is this hard on those pumps? An unnamed car show seems to burn up electric fuel pumps on every episode because of poor install.

Old pumps are only a couple years old, Mercruiser pumps mounted to sea water pumps. Piss poor design on Gen6 engines. Pumps tend to leak and push on the mounting side into the sea pump which is oil filled and over pressurizes the sea pump and blows by the seal. Not only creating oil mess, but oil with some gasoline in it.

Rob,

Are you referring to the mechanical pumps? The tech at Weldon told me their pumps will pull up to 12' vertically, starting dry, and don't care whether they are pulling or pushing through a restriction of any kind.

Thanks. Brad.

Just throwing this out there just for general conversation, I used to have that set up in a old boat, and I should’ve tried, but I always wondered if putting in something like VR 1 20 W 50 instead of the gear oil would’ve been better for those set ups. That oil is designed to handle a decent amount of fuel in it without having issues, where obviously I’ve never tested fuel in gear oil. Lol. Anyways wonder if anybody’s ever tried it?