350 mercruiser question

driver_dav

Petty Officer 3rd Class
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May 1, 2013
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96
ok so i bought this boat, been sitting for ten years atleast, go to turn it over and the starter does a hard click like the head is popping out but not turning the engine over, i try to turn it by hand and it just tightens the crankshaft bolt, i oiled the 7 out of 8 cylinders and gonna let it sit over night, any suggestions, it is a 350 5.7 mercruiser, please no engine is junk get a new one.
 

achris

More fish than mountain goat
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May 19, 2004
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27,468
Re: 350 mercruiser question

Sitting for 10 years is likely to have allowed some rust in the cylinder bores. As a couple of valves will have been open, then it's also likely they'll be stuck too. Best thing you can do is pull the drive off and see if you can turn the engine without the drive. If you can, then you will need to investigate why the drive is locked up. If you still can't turn the engine (with the spark plugs removed of course), then you will probably need to pull the engine and strip it down...

Chris........
(Trying not to say 'that engine is junk, replace it'... :D :D :D)
 

ktbarrentine

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Dec 12, 2011
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1,296
Re: 350 mercruiser question

Hope you got a good deal. Why only 7 of 8 cylinders oiled? More likely need pb blaster.
 

driver_dav

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May 1, 2013
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Re: 350 mercruiser question

Hope you got a good deal. Why only 7 of 8 cylinders oiled? More likely need pb blaster.
for some reason the spark socket won't go onto the final one the exhaust won't allow it by minimal amounts
 

driver_dav

Petty Officer 3rd Class
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May 1, 2013
Messages
96
Re: 350 mercruiser question

Sitting for 10 years is likely to have allowed some rust in the cylinder bores. As a couple of valves will have been open, then it's also likely they'll be stuck too. Best thing you can do is pull the drive off and see if you can turn the engine without the drive. If you can, then you will need to investigate why the drive is locked up. If you still can't turn the engine (with the spark plugs removed of course), then you will probably need to pull the engine and strip it down...

Chris........
(Trying not to say 'that engine is junk, replace it'... :D :D :D)

do you think it sounds done for though?
 

Bondo

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70,468
Re: 350 mercruiser question

ok so i bought this boat, been sitting for ten years atleast, go to turn it over and the starter does a hard click like the head is popping out but not turning the engine over, i try to turn it by hand and it just tightens the crankshaft bolt, i oiled the 7 out of 8 cylinders and gonna let it sit over night, any suggestions, it is a 350 5.7 mercruiser, please no engine is junk get a new one.

Ayuh,... Pull the drive off, just to be sure whether it's the Motor, or the drive is Seized,...
 

driver_dav

Petty Officer 3rd Class
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May 1, 2013
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96
Re: 350 mercruiser question

If the boat was properly winterized would it seize up from just sitting for 9 plus years
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: 350 mercruiser question

If the boat was properly winterized would it seize up from just sitting for 9 plus years

Definitely. You must remember that whatever spot the engine stopped at, at least 2 valves will be open. That will allow moist air in and out of the cylinders. That will cause those cylinder bores to rust, and 9 years of rust... I'd venture to say that engine is probably good for a mooring, and not much more.

Chris..........
 

driver_dav

Petty Officer 3rd Class
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May 1, 2013
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96
Hey not sure if anyone is still following this but this year I have been tearing into the engine, I have it stripped down to the block, pulling the block in the morning but so far what I have found is that upper intake has rust, heads have rust and only 2 out of 8 cylinders have rust, not sure how deep it is in the cylinder walls yet, stripped it in 5 hours and put it on pause. From what I see in the heads they are covered in rust, what is the steps for the heads and others. Under the intake its spotless, topside of heads is spotless, and all gaskets are clean and almost look like the were replaced not long before it sat, i'm pulling the oil pan and starter tomorrow.

But what is my next step with the heads, intake and block?
 

matth121

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May 19, 2011
Messages
275
does it turn over now at the crank? if you plan on pulling the pistons you could get a bore honing attachment for a drill that will allow you to freshen up the cylinder bores, probably need to throw a new set of rings in it. not much to do with the intake as long as its clean and has nothing in its passages. as for the heads, might be best to take them to a machine shop to have them checked/cleaned/ tested. might need new valves. good luck bro
 

driver_dav

Petty Officer 3rd Class
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May 1, 2013
Messages
96
I started cranking by hand after letting it sit with fogging oil for a bit, and scrubbing it with a dish bristle pad and they move smooth as butter, there is still some roughness from rust so honing should work, I also had some fogging go around one piston so I do plan on replacing the rings.
 
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