Pre pump filter for EFI
 

What is tranditionaly run pre-pump? The AZM setup I have came with a Mallory carburator fuel filter after the fuel pump. I can put the 5 micron efi filter into the mallory housing, but that leaves the pump unprotected. In an old boat with an old fuel tank, I figure that could cause problems. But putting the Mallory filter in line before the pump could really restrict flow.

What is normal for an EFI system on a boat? Two separate filters? One course filter before the pump and a finer one after?

Any thoughts or advice would be appreciated.

I run 2 filters, a low restriction filter before the pump. I found a glass filter with AN fittings that disasembles. Then after the pump I run a High flow/High pressure aftermarket fuel filter/water separator. I got the housing from EMI and I use a Wix high pressure water separator fuel filter. I use the Holley MPI kit 1000cfm trottle body with 42lb injectors. Hope this helps.

You should have the water seperator/filter before the pump. That filter is not made to have pressurized fuel running through it and it could be dangerous. Those filters get rust in them from water and could get a hole in them from excessive rust. You will then pump pressurized fuel into the bilge. I run the water seperator first, then the pump, and then a high pressure filter after the pump to catch any parts if the pump fails. I use one from Aeromotive. I think it is like 50 micron. It is made to catch the larger pieces to stop them from going into the fuel rails and injectors. It will handle like 100 psi. Hope this helps, Eddie.

ANy idea if any of the off the self water separators will handle the flow of 600hp on the vacume side? The ones at West Marine say they're only good to 200hp.

Anyone know a part number for the water separator on an old carbed HP500?

Go with what Mercury Racing uses -- a Ramco water/fuel filter/separator then the pump then the smaller 10 micron filter. The second filter should be changed very often -- depends largely on how long the boat sets between use.

A Ramco filter is the only prefilter that can keep up with a Weldon pump which is found on all 850's, 1075's & 1200's.

I am not using the stock filters. I am using High pressure filters. They are like $60 a piece. I am not using the stock mercury water separator/fuel filter. Be sure to keep the low pressure filter as low as you can in the bildge along with the pump. Then run the output of the pump to a High flow High Pressure Filter Separator. I have had this installed on my boat this way for 8 years. The filter will not rust. You should change your filter every year or 2 anyway. This is assuming you do not have a pump in the tank. You need to have the pump as low as you can so it can draw the fuel from the tank.

8 whole years ??? If I had been only doing it that long I would be listening to all of Eddie's dumb comments. But thats just me. :rolleyes:

OK, I edited my first comment. This is not my post. I am not a marine dealer. I do all my own wrench work. I installed my system acording to manufactures recomendations in 2002. I am just trying to put somone on the right track. I was told at the time this is the best way to do it and it works. I am just giving my advise. He probably thought I was using the stock mercury setup. My only concern with running the separator before would be additional restriction before the pump.

Any idea where to buy one? I did a search and came up empty for anything Ramco marine. I'm guessing it's probably pretty pricey. I looked at the high capacity stuff CP and Hardin sell and it would seem I'd be better off buying two normal ones and running them in parallel. That way a prefilter change would be $18 instead of $50

What does that mean? What makes my comments so dumb???