Twin Merc 5.7L need

tmh

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Aug 16, 2006
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I am considering purchasing a very nice mid-90' Formula 27' cruiser. It is being sold by someone I know (not a friend, just some guy i know). The boat is very inexpensive compared to similar boats I see listed AND in absolutely great cosmetic shape - nearly like new. However, one BIG problem - the engines are crapped out. He wants to sell it fast because he needs the cash now so I'm trying to quantify the likely cost of fixing or replacing the engines.

Here is what he says about the engine problem:

"last season before taking the boat out I felt loss of power so I did a compression check on all cylinders, and number 4 and 6 cylinders had no compression, so I filled oil through the spark plug holes and re tested, and still it had no compression, so this shows that the valves are burned on those cylinders. the motors idled fine except when needed power. so if you can swap heads on the motors you got yourself a beautiful boat"

Now, I know this guy well enough and have talked with him so I do believe he thinks they just need the heads swapped ...... and maybe that's so. However, i also know it could be lots of other issues. The engine looks clean and well-maintained externally.

Both engines have similar problems and need rebuilding, according to the seller. maybe replacing I guess. It's a 1995 boat so I'd be fine using a remanufactured engine or whatever - as long as it does the job.

there is a well-regarded shop near me that does rebuilds for $1650, plus cost of heads if needed. So, around $5k for both engine rebuilds, heads and in/out. That keeps me well under the value of the boat still. What I'm wondering is what COULD be cheaper (just heads needed ???) and what could cost more? I just want the info to make an informed decision, knowing the risks.

Thanks, as always.
 

Bondo

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Re: Twin Merc 5.7L need

the motors idled fine except when needed power.

Ayuh,... It's awfully hard to believe V8s running on 6 cylinders idle smooth...

If you're going to Jump,..

Just Plan on Replacing the motors.....
 

Zackman

Petty Officer 1st Class
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Dec 3, 2005
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Re: Twin Merc 5.7L need

I am considering purchasing a very nice mid-90' Formula 27' cruiser. However, i also know it could be lots of other issues. The engine looks clean and well-maintained externally.

I would think, given the conditions of the motors, that you can expect many more issues. Did he keep maintenance records? Have you thought about getting it checked by a professional surveyor?​
 

tmh

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Re: Twin Merc 5.7L need

Yes, the engines would get checked by a certified mechanic as a condition of purchase. Also, yes, i understand there is a chance I need to replace the engines. I don't think I'd need a complete crate engine because the fixings should mostly be fine, correct?

Again, I know the risks, just looking for best-case/worst-case. As I said, the boat is in great shape otherwise, so I know it wasn't abused. Some issue caused the problem - it was run in the Hudson river which is salt water (diluted ???) so maybe that caused the problem.
 

mkast

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Nov 6, 2002
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1,934
Re: Twin Merc 5.7L need

I have run into quite a few individuals that said, "The boat is in great shape, except..."
In reality, the boat that was in great shape had a rotten transom, rotten stringers, soft floors or etc etc, but looked great!
In your case, plan for the worst. Two engine replacements.
Hope for the best, local tech college rebuilds both engines for six hundred apiece.
 

Alumarine

Captain
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Feb 22, 2005
Messages
3,739
Re: Twin Merc 5.7L need

Don't forget to get the outdrives checked.

They could cost more to repair than the motors if they have issues.
 

krisnowicki

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Messages
1,172
Re: Twin Merc 5.7L need

you can get two long blocks for about 1200 each from rapido marine and sqap all your tin over. It owuld be about 2800 delivered for both and the guy raul is aweosme.....
 

tmh

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Re: Twin Merc 5.7L need

you can get two long blocks for about 1200 each from rapido marine and sqap all your tin over. It owuld be about 2800 delivered for both and the guy raul is aweosme.....

Yeah, that's kinda what I had in mind. Maybe some marine accessories would need replacing also. Definately need the drives checked as well.

I'll admit, I take risks sometimes for great deals. Most have worked out, a very few have not. I try to quantify the risk and make an informed decision. So people DO tell the truth about the condition of what they're selling. Some don't. i get that, not a worry - I do my best to gauge their honesty and am usually right. If i'm wrongI try to cover myself with things such as a "contingent on successful survey" clause in the deal.

This IS a sweet boat! I do like to work deals such as buy boat, get long block, pay mechanic to put together and install. If it comes out to much less than the same thing in working order, then I made a deal. If not, maybe I lose on that one.
 

legoman67

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Oct 16, 2008
Messages
636
Re: Twin Merc 5.7L need

if you have a tighter budget keep your eyes open on your local craigslist. We got 2 merc 5.7's to repower our boat with only about 200 hours each on them. now dont kill me......for $1500. Complete package, one opposite rotation...
 

tmh

Lieutenant Junior Grade
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Aug 16, 2006
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1,136
Re: Twin Merc 5.7L need

if you have a tighter budget keep your eyes open on your local craigslist. We got 2 merc 5.7's to repower our boat with only about 200 hours each on them. now dont kill me......for $1500. Complete package, one opposite rotation...

Het, I bought a 5.7L off eBay last year for my current boat (upgrade 5.0L). Works great! Complete for $1100 I think - you got a better deal.
 
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