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-   -   EFI to Carburetor (https://www.offshoreonly.com/forums/do-yourself-boating-budget/367120-efi-carburetor.html)

Mercedes450slc 06-25-2020 01:29 AM

EFI to Carburetor
 
I have a 1994 Mercruiser 454 magnum MCM EFI 385 hp that \i would like to convert to a carburetor. If it had a newer efi system I wouldn't even consider switching but it has been one thing after another. I think the ECM may be toast now. The boat sat for 9 years and was not properly winterized. I have put in a rebuilt base engine but cannot get it to run right. What is involved in switching to a carburetor ? Intake, carb, distributor, fuel pump ? Are there kits available ? Any help would be greatly appreciated.

boostbros 06-25-2020 05:49 AM

its easy and will run great use a 1410 eldebrock

AllDodge 06-25-2020 06:50 AM

Remove the motor EFI harness leave the motor harness. Depending on which serial number, would run alarm switches from the Tan/Blue wire. To determine would need serial number

diamondk 06-26-2020 06:35 PM

I have a 1998 Doral with a 5.7 mercruiser. Is there a carburetor that would replace the efi unit on it?

AllDodge 06-26-2020 07:23 PM


Originally Posted by diamondk (Post 4745547)
I have a 1998 Doral with a 5.7 mercruiser. Is there a carburetor that would replace the efi unit on it?

Eldelbrock 1409

mike tkach 06-26-2020 09:41 PM


Originally Posted by Mercedes450slc (Post 4745220)
I have a 1994 Mercruiser 454 magnum MCM EFI 385 hp that \i would like to convert to a carburetor. If it had a newer efi system I wouldn't even consider switching but it has been one thing after another. I think the ECM may be toast now. The boat sat for 9 years and was not properly winterized. I have put in a rebuilt base engine but cannot get it to run right. What is involved in switching to a carburetor ? Intake, carb, distributor, fuel pump ? Are there kits available ? Any help would be greatly appreciated.

as far as i know there is no kit but it can easily be done,i have a boat with a 502 mag efi i am converting right now.you will need a carb,intake manifold,ignition system and a low pressure fuel pump.i have done several of these conversions and all the boat owners say it made their boats run a whole lot better.

SB 06-26-2020 10:07 PM

I fid the 502MPI to carb. Used the EST distributor from the MPI. Being a Gen V the MPI had the sea water pump mounted mechanical pump, which I used. Removed vst electric pump set up of coarse. Luckily the dist had the module with advance curve they use in the Voyager Ignitions. If yours doesn’t do advance, you can swap in a module that does. We have noted these modules in the past on OSO and other places.

Mercedes450slc 06-26-2020 10:16 PM

Hi,
When you say "ignition system" do you mean coil and distributor ? Any other components ? Thanks !!

Excess 06-27-2020 08:31 AM

Has anyone done this with 565's ? I want to get rid of all the computer stuff and DTS and go back to old school mechanical throttles and shifters

mike tkach 06-27-2020 09:47 AM


Originally Posted by Mercedes450slc (Post 4745569)
Hi,
When you say "ignition system" do you mean coil and distributor ? Any other components ? Thanks !!

the one i am currently doing is getting a msd dist,ignition box and msd coil.


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