350 MAG MPI Reman maybe Gen II??

[MileMarker74]

I am having a fuel restriction on a recent repower 350 MAG MPI MIE Inboard with 1:1 direct drive transmission. Pictured is the Quicksilver number from the block. We tested the boat with a portable tank to rule out tank and pick up’s which are all new. The motor is a Reman purchased from Doug Russell Marine. The motor sat in storage for two years previous to install. Fuel filter is new also.
The first test run boat came out of the hole like a bat out of hell and ran wide open for about 10 seconds then it surged and bogged down to about 2500 RPM’s at WOT. Now after checking above things she still will only do 2500 RPM bogged down. I have taken the fuel screen off under the fuel regulator and there is no visible debris. Is there another screen built into the fuel pump or should I direct my attention to the injectors?? Thanks in advance.

 

[Scott Danforth]

clean the fuel system. from the tank to the injectors

the motor ran great until all the crud in the fuel system plugged up the filter in the pickup (remove and discard), Anti Siphon valve (clean), probably the pump (clean) , and most likely the injectors (send in and get clean).

 

[MileMarker74]

Absolutely I am sending the injectors to be cleaned.

 

[Fun Times]

Also check the fuel pressure when the fuel pump system is all reassembled…, Usually when the screen in your photo is clogged it creates a high fuel pressure situation vs low pressure.. That’s the fuel regulator return part of the system…

I Don’t recall a screen at that High psi fuel pump but your system also “might have” a low 12v psi pump before the fuel filter Assembly, then there could be a screen before/at the inlet side of the fuel low psi pump that could need cleaning while checking the whole fuel system from inside tank to injectors.

Try Connecting a separate 5 gallon fuel tank and go run the boat to see if that helps any.

Here should be this Reman engine parts catalog,

350 MPI Crate - 1G400000 & Up

350 MPI Crate - 1G400000 & Up

www.mercruiserparts.com

 

[MileMarker74]

Also check the fuel pressure when the fuel pump system is all reassembled…, Usually when the screen in your photo is clogged it creates a high fuel pressure situation vs low pressure.. That’s the fuel regulator return part of the system…

I Don’t recall a screen at that High psi fuel pump but your system also “might have” a low 12v psi pump before the fuel filter Assembly, then there could be a screen before/at the inlet side of the fuel low psi pump that could need cleaning while checking the whole fuel system from inside tank to injectors.

Try Connecting a separate 5 gallon fuel tank and go run the boat to see if that helps any.

Here should be this Reman engine parts catalog,

350 MPI Crate - 1G400000 & Up

350 MPI Crate - 1G400000 & Up

www.mercruiserparts.com

How do I remove the fuel rail and injectors on this motor? I don’t want to break anything.

 

[QBhoy]

What diz cap do you have on this ? Is it the flat one ?

 

[alldodge]

How do I remove the fuel rail and injectors on this motor? I don’t want to break anything.

Before removing, what was the fuel pressure at the rail?

 

[kenny nunez]

Before you start get the tool that releases the fuel line from the rail. Hopefully you have compressed air, blow the rust,dirt out from around the injectors. Remove the throttle body. Remove the electrical connections and squirt some WD40 or similar around the injectors to help them come out. Unbolt the rail and rotate each injector then gently lift it off the rail. The injectors may also come up with the rail. Keep account of all the “O” rings. Cover all the holes.
That is the way I removed them on my Donzi to have the injectors purged.