Mercury fuel injected

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Jan 9, 2024
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Swapping engines Can I change a mercury with fuel injection and freshwater cooled from a volvo 5.7 saltwater carbureted
 

alldodge

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We're going to need a bit more info to make sure.

But if your saying can you take a Merc 5.7 and swap for a VP 5.7 and they are the same type, then yes.

Type meaning both pre-vortec or both vortec
 
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I have a situation where I thought my Volvo 5.7 natural carbureted and salt water cooled has seized during the winter! I then bought another boat that had a 5.7 fuel injected and fresh water cooled merc. Both are pre vortex. I have two options: flip everything from the second boat including controls and stern drive, or taking exhaust, rear flywheel and drive and placing on the merc engine. I know I would also have to swap throttle rack . Is the nine pin a universal as far as the electric is concerned?
 

alldodge

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Yes 9 pin will be the same, neither use pin 9 and in most cases it's not there

Double check the intakes. Pre-vortec has 12 bolts. Vortex has 8 bolts
 

QBhoy

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I have a situation where I thought my Volvo 5.7 natural carbureted and salt water cooled has seized during the winter! I then bought another boat that had a 5.7 fuel injected and fresh water cooled merc. Both are pre vortex. I have two options: flip everything from the second boat including controls and stern drive, or taking exhaust, rear flywheel and drive and placing on the merc engine. I know I would also have to swap throttle rack . Is the nine pin a universal as far as the electric is concerned?
Is the Merc definitely not vortec ? An efi merc before 96 wouldn’t be too common a thing perhaps.
 
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I’m pretty sure the engines are both prevortex, the fuel pumps different although both electric. I intend on staying with the mercury system. The mercury boat was of an older vintage 1977 but like most boats had their engine swapped many times. It was for this reason I purchased the boat as, the engine, cooling system and fuel were modern. The starter, alternator and brackets were much older. The mounts are identical on both engines!
 

Scott Danforth

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I stand corrected, it has eight bolt. More problems I assume
no problem at all. if you know what you are doing.

you would need to make sure the VP bell housing has room for the larger 168 tooth flywheel.

the exhaust will need to stay VP (merc manifolds will not line up with VP stuff)
 
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