from efi to carb ....engine wireing harness
 

does merc make a harness that you can buy to go from a 502 mag .. or 500 efi ... to a carb motor or do you just make your own

i would still like to be able to unplug at oem connector

Are you talking about the boat harness or the engine harness?

Im talking about the engine harness i want it to look clean on the install and im making a parts list

harness you have can be used . The upper half
Is the efi side there is 1 plug separating the 2
I've done it many times

so the harness for the injectors is its own harness which is apart from the main harness

i changed out mine frow
m efi to a carb set-up.my motor was a 94 mercuser,502mag,efi to a 502 carb set-up.i got a new harness from a local dealer.i used for refrance a 89-92 carb wireing harness.this was about110.00.i also changed the distributor to a msd and use a marine box.that was it.there was some minor wiring,but nothing major.everybody told me i was going to take big hit in fuel consuption....i lost something like .5gallon a mile,,,,,,,,a small price to pay for being able to have a boat that i can work on/trouble shoot.i am a old school kinda guy and dont know alot about efi.

Just change 2 on my boat part # 84861240A2 the cost about $200 each....

the EFI harness is seperate....just disconnect in the black ecm box and you are good to go....

I'm in the process of going from efi mag 502 to a carbed set so I'm interested in the break down of what needs to be done.

I was under the impression that I need new wiring harness for a carb application,new distributor and carb module. Am I close with this or way off base. I would love to here what exactly I need to do from those who have done this conversion.

Thanks

ok, I will say this more time..the HARNESS for EFI is seperate...unplug the EFI stull and roll on...just did a 98....simple if you can't get past this give up..

I got that part. I'm concerned with the distributor. Just need to get thunderbolt iv parts and slap it in?

i would assume computer controlled ignition wouldn't work without the computer. some type of stand-alone ignition would be necessary.

When I removed the EFi from my motor, I simply unbolted the lower manifold and and removed all the wiring connections going to the main harness. I was going to use the stock distributor and stuff but ended up not using it and used all MSD ignition items. I think there are 2 or 3 plugs that have nothing going to them that I bundled together and ty wrapped them neatly together out of the way. No need for a new harness just use the one you have.