How to connect remote fuel tank to Mercruiser 6.2L 300HP MPI IO

platon20

Seaman Apprentice
Joined
Jul 15, 2020
Messages
34
The service manual suggests that there are 2 ways to connect a remote fuel tank -- thru the fuel inlet on the fuel/water separator filter or directly into the fuel rail. However the manual doesn't really give details or pictures on how to hook it up.

I assume connecting to the fuel separator is better, so that's the route I'm going to try.

I have some pictures below. Should I disconnect the main tank fuel line at the brass fitting? Or try to disconnect it higher up right where it enters the fuel separator? How much gas is going to spill out into the bilge, assuming that I clamp the lines?

BTW, I've already searched youtube for this and they only show the process for mercury outboards, not IOs

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alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
42,649
Have not seen the setup your showing. Looking at the latest 377 (6.2 EC) motor, I'm also unable to find it. Maybe a serial number would help

Unsure why your using a remote tank but guessing it may be for fuel oil mix for winterizing. If this is the case, connect remote tank to input side of the fuel filter
 

QBhoy

Fleet Admiral
Joined
Mar 10, 2016
Messages
8,348
Take the filter off and fill it with a 2 stroke mix. Or run the main tank as low as you dare and mix that.
If you really want to go the remote tank way, pull the hose off the tank or off the filter inlet and run a hose into the remote tank. I’ve aways just ran the main tank really low and mixed a gallon of super unleaded at 40/50-1 of tcw3 oil. Throw that in when it’s as close to empty as you dare. This was an after thought by merc after guys tried to fog down the throttle body and it messed with things.
 

RaceCarRich

Petty Officer 1st Class
Joined
May 31, 2015
Messages
234
My old mechanic would just fill the filter housing with the mix when he changed the filters. I did same this year. Ran it about a minute at about 1300 rpm. I could tell it was running on the magic juice because it wasn’t idling well.
 
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