New Project -- 4.3 Merc engine seized

Slyder69

Cadet
Joined
Apr 20, 2020
Messages
8
Good Evening,

New to the group, had a crime of opportunity present itself to us and acquired a 2006 Starcraft Seastar with a 4.3 Mercruiser. Previous owner had an issue running across the river and oil apparently drained out of the quick drain hose while running. He shut it all down quickly, took it in for a diagnosis and decided he didnt want to spend the money to repair. its basicallybeen sitting for a couple years sans oil. I have removed risers and exhaust manifolds, plugs out and shot marvel into the cylinders. cannot get it to turn over. I have resigned myself to the fact that I will be pulling the engine but was wondering if there is any way to tell how bad it may be or a trick to try to turn the crank over to break it loose.

I am in Jacksonville Fl and am searching out machine shops for a rebuild or for an economical short/long block.

Any Info or advice would be greatly appreciated.

Thanks, Mike
 

Bondo

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71,308
Ayuh,....... Welcome Aboard,...... Pull the drive, if ya haven't already, as it's splined to the crankshaft,.....

If the motor still won't turn over, ya then know it's the motor, 'n the drive has to come off to pull the motor anyways,.....
 

Rick Stephens

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Aug 13, 2013
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6,118
I'd be pulling the drive and motor and opening the motor up. No way I would even try and crank it over. Just a complete disassemble and inspect everything as you go. That way you do no more damage. It probably is a good core to start a rebuild, but not if it gets abuse after being left sitting.

Welcome to the forum!

Rick
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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Take the 45 minutes to pull the drive and motor.

No way to diagnose with it in the boat
 

Slyder69

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Apr 20, 2020
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8
Thanks so much for the quick responses, confirmed what i was already thinking and have researched over the forums!!
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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and what have you confirmed...... that the motor needs to come out, or the motor has been sitting siezed and you need a new long-block?
 

Slyder69

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Apr 20, 2020
Messages
8
No, just that I will be pulling the motor this weekend. I found several posts about the drive possibly being frozen as well and hadn't even considered that. Outdrive and motor coming out and i will tear into the block. Hopefully find that I can at least rebuild the block instead of replacing. After inspection i suppose the next step will be pricing rebuild vs replace once i get into the engine
 

Slyder69

Cadet
Joined
Apr 20, 2020
Messages
8
Engine is pulled and sitting in the garage, getting some quotes for rebuilding. Outdrive does not seem to be seized, After getting enngine out noticed flywheel coupler was very badly rusted around shaft where the grease fitting is (from water being in bilge?), as well as some rust/white grease around the gimble bearing. Am i wrong to assume that I should be able to reach in and spin the gimble bearing fairly easily with my fingers through the bellow? Just want to take care of any maintenance/replacement of things while engine is out and have open access to everything on the transom from both sides.

thanks in advance
 

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Rick Stephens

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Aug 13, 2013
Messages
6,118
Time to get the Mercruiser manuals for that drive and motor and start in on everything.. Might be able to get a link here from someone on downloadable manuals. To start you can go to boatinfo.no and look them up online.

Yes, you should be able to spin the gimbal bearing and it should be smooth as silk. Everything needs looking at and maintenance performed though.

Rick
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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looks like the boat sat with water in the bilge for a while
 

Slyder69

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Apr 20, 2020
Messages
8
Would the flywheel coupler be ok even with the corrosion around the input end? The grease nipple is working fine and the rubber within the looks great. wire wheel and some paint or replace???
 

Rick Stephens

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Aug 13, 2013
Messages
6,118
Would the flywheel coupler be ok even with the corrosion around the input end? The grease nipple is working fine and the rubber within the looks great. wire wheel and some paint or replace???

Paint is paint. Sand blast it, hand sand it, whatever. The rubber to spline is what matters.
 

Bondo

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Apr 17, 2002
Messages
71,308
The rubber to spline is what matters.

Ayuh,..... Welcome Aboard,...... While the rubber is important, the splines themselves are a wear point, especially if not greased often enough,......

The tops of the splines should be nice, 'n square, not real pointy,.....
 
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