Removing Mercruiser 4.3L

Chadbud

Petty Officer 3rd Class
Joined
Aug 13, 2016
Messages
80
Hi guys! In the process of restoring my 1986 Four Winns 190 cubby.. my next step is to remove the engine, which I plan on having rebuilt locally.

As far as I understand it now, I’ll likely have to remove the outdrive.. and then removing the engine mounts. Then, I also I’ll have to remove exhaust manifold connections and various electrical connections from the boat motor before pulling it out of the boat.

Here he are my questions:
-Is there anything I’m missing as far as disconnecting the motor before attempting to pull the engine?
-I plan on putting the engine on to a crate and then loading it into the back of my truck before delivering it to my local machine shop for rebuilding.. should I build my own engine crate for this process?
-What does the engine machine shop expect me to deliver with the engine on crate? It’s a Chevy or GM 4.3l V6 mercruiser. I assume I give them all the parts to engine I have, including the exhaust manifolds and eclectical connections.
-I’ll likely need to use my air compressed bolt drill to remove the engine mount bolts since they’re hard to reach and likely tightly bound into the boat.
-Is there anything else I’m missing? I remove the outdrive, bellows, and drive shaft where the outdrive connects to the engine shaft. Once this is done, it’s just a matter of disconnecting the electrical equipment and bolts connecting the engine to the boat inside, right?

anyway, thank you guys for helping me work through this. I haven’t found step by step instructions online or through YouTube to appropriately remove an onboard engine from a boat.. so I just want to make sure I’m doing everything correctly so I can deliver the engine to my machine shop in a condition they can easily work with when rebuilding the engine.



That’s where I’m at guys! Let me know if I missed something or if you guys have any helpful tips in this process..

Thank you!!
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,581
Look on the rear of the motor for smaller ground wires going from the motor to the transom plate.

In most cases, a rebuilder will take the entire motor, rebuild and give it back ready to reinstall.

A machine shop takes the long block (heads and block without intake), and rebuilds the block only. Then you reinstall intake, carb manifolds, etc

So it depends on how much you want or are willing to do. The more you do the more money can be saved, but does need to be done correctly. Not that hard, requires some tools and the manual
 

tpenfield

Moderator
Staff member
Joined
Jul 18, 2011
Messages
17,620
control cables . . . fuel line . . . water intake hose

Just remove the lag bolts that are holding down the engine mounts and lift the engine and front mounts together.

Put some 6x6 blocks on the pallet to rest the front motor mounts on and strap the engine down to the pallet. If you have an engine hoist, then you can lift engine & pallet as one onto your F-150 pick-up truck (of whatever vehicle you have)
 

CamaroMan

Petty Officer 1st Class
Joined
Mar 18, 2016
Messages
323
what tpen said, remove the lag screws that go down into the stringers with a wobble socket if u can get in there - another option is to remove the mount bolts (3 x 9/16 socket per side?) - . Remember drive has to be in fwd gear to come off. Instead of messing with the dust plate screws, just undo the 2 large bolts in the rear facing up - 3/4 socket size i think. That and the side mounts and other motor related connections and she will lift free.

As u remove motor check underneath for oil lines catching etc..

Good luck! if this isnt a marine shop have them check marine specs on piston to wall clearance, on boats its usually 1thou more than motorcars -
 

harringtondav

Commander
Joined
May 26, 2018
Messages
2,438
Just remove the lag bolts that are holding down the engine mounts and lift the engine and front mounts together.

Apparently people have better luck with that than I did. Three of four of my lags twisted off. Two of four in my pal's boat. I had no luck excavating the stumps. So I built two aluminum mount plates with tapped holes to secure the front mounts, and two clearance holes that held everything down with SS hanger bolts. If I ever have to pull the engine again, it will be a snap.

I had to lower the mounting surface to make up for the additional height of the plates. I wish the boat builders would also use the SS hanger bolts. Nearly zero change of twisting off.

Mount fix.PNGLarson stringer.jpg
 
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