4.3 MPI cooling diagram

SteveRay

Petty Officer 1st Class
Joined
Oct 20, 2004
Messages
338
Does anyone have a cooling diagram for 4.3MPI 2005 Merc?
Backflushing through the hoses with pink and can't seem to get the pink to come out the water intake on the Alpha leg....seems to be coming out somewhere else.....Just want peace of mind
 

4Winns2

Petty Officer 1st Class
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Nov 2, 2006
Messages
327
Re: 4.3 MPI cooling diagram

On my 4.3 there is a hose that runs from the transom to the thermostat housing. Just track it from the transom down by the outdrive. It's true that on a back fill you should see pink running out of the leg onto your driveway. I usually take this hose off and blow through the hose at the thermostat housing to clear water. Here again though it should **** pink on the driveway when the block and passageways fills.
 

SteveRay

Petty Officer 1st Class
Joined
Oct 20, 2004
Messages
338
Re: 4.3 MPI cooling diagram

Mine is draining out on the driveway but I dont think its coming out of the water pickups.....The '05 has the 3-point drain system and I am also told I may have the cool fuel module as well....Maybe I just need to have someone watch while I backflush to tell me where its coming out.
 

4Winns2

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Nov 2, 2006
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327
Re: 4.3 MPI cooling diagram

You should see it coming out of either or both pick ups (they have little grills over them) beneath the cavitation plate. For piece of mind (something we all want when it comes to water freezing inside the engine and hoses), I would give a call to the local marina and just ask. Also, do you have a service manual that depicts laying it up for the season? Always a good tool for expensive toys.
 

jmarty10

Chief Petty Officer
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Aug 6, 2007
Messages
560
Re: 4.3 MPI cooling diagram

Give mercury marine a call. They have answered a few of my questions
 

Bondo

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Apr 17, 2002
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Re: 4.3 MPI cooling diagram

Backflushing through the hoses with pink and can't seem to get the pink to come out the water intake on the Alpha leg....

Ayuh,... Which Hose,..??
 

SteveRay

Petty Officer 1st Class
Joined
Oct 20, 2004
Messages
338
Re: 4.3 MPI cooling diagram

Ayuh,... Which Hose,..??

The hose that feeds into the T-stat housing.....on my old 3.0L it I used to fill the hose with pink and it would flow out of the water pick ups on the drive.
I think this is just because of the 3 point drain system flow diagram.....I just cant seem to follow the water intake line from the transom into the T-Stat.
 
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