1989 OMC cobra taking on water when beached

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essick5

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I have a 1989 OMC cobra stern drive with a 5.0L that when running or even just floating will not take on water, but if i beach and trim down and put just a little pressure on the boat i will take on water to the point it will fill the ski well. Im hoping its not a transom. has anyone run across a problem like this?
 

Black as

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Re: 1989 OMC cobra taking on water when beached

Have you tried jacking up the front of your trailer with the boat on it of course and filling the well with water, by the sounds of it I'm sure you would find your problem.
 

Bondo

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Re: 1989 OMC cobra taking on water when beached

but if i beach and trim down and put just a little pressure on the boat i will take on water to the point it will fill the ski well. Im hoping its not a transom.

Ayuh,... I would guess that it Is,...
The only way to find out is, Look...
 

Don S

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Re: 1989 OMC cobra taking on water when beached

Ayuh,... I would guess that it Is,...
The only way to find out is, Look...

I agree with Bond-o, when you are beached and put the drive down with a little pressure, that pulls the transom shield away from the transom.
When not beached and the drive is down or when running, the bottom of the transom shield is pushed against the transom.
You probably still have the leak when not beached just not as bad.
Next time you beach the boat, look for the leak, use a mirror, flashlight, or even a digital camera.
 

HT32BSX115

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Re: 1989 OMC cobra taking on water when beached

Howdy,


I'll also add that if you are in fact pulling the lower part of the transom mount away from the transom with even a little "pressure", at the minimum , you need to pull the drive and engine and replace the transom.

When you get the engine out, you'll probably also find that the engine mount points and rear stringers are probably on the fast-track to seriously ROTTEN!

It won't be all that hard to determine all of the above. If that's the case, you need to find yourself another boat...... It won't be worth tearing into it and doing a complete rebuild of the transom, stringers & floor just to put an obsolete engine and drive back in.

Running it as-is, will result in stranding you (from the loss of engine-drive alignment and subsequent coupler failure) Unless it sinks first!


Sorry about that.



Rick
 

infideltarget

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Re: 1989 OMC cobra taking on water when beached

It may be worth it...to him...to tear it out and fix it. The OMC Cobra may be "obsolete" but is still viable and reliable, and I have had no problems finding parts for it. On the contrary, I had a hell of a time trying to fix a Volvo-Penta SX drive be cause of the lack of parts/service for it...and it is far newer. What I did find was so outrageously expensive that it caused me to abandon a boat because of the cost to rebuild the drive. Granted, mercruiser is more plentiful, and cheaper to fix. But if you already have a good running OMC setup, why not fix the boat? The cost of fixing will surely be cheaper than the cost of replacement with a different boat, and whatever problems it brings. And it will always be cheaper than the $$$$$$$$$ it cost to buy a new boat. Essick5, look in the restore section. You will find a lot of good info on what it takes to FIX your boat there. Good Luck!
 

bruceb58

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Re: 1989 OMC cobra taking on water when beached

I had a hell of a time trying to fix a Volvo-Penta SX drive be cause of the lack of parts/service for it!
I can get practically any Volvo part 2day shipped to my house. They get drop shipped from Volvo themselves. As far as repair, their are MANY shops in the LA area that service Volvos. I have my choice of around 10 within 50 miles.
 

infideltarget

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Re: 1989 OMC cobra taking on water when beached

location, location, location... and i did mention that what parts I found were prohibitively expensive, especially when compared to OMC or especially Mercruiser parts. $4000 to rebuild a drive? $7000 for a reman drive (+ core)? please. no thanks. i can find OMC Cobras for $1000 ready to hit the water, and SEI sells warranteed mercruisers for $1395. I think the OP would be able to fix it and keep his OMC and be happy cheaper than junking it and starting over just because some say its obsolete, thats all. some of us have to operate on a budget.
 

bruceb58

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Re: 1989 OMC cobra taking on water when beached

Not sure where you looked but I googled rebuilt Volvo SX and got this site. This is the first site I clicked on. Rebuilt $4k.

http://www.zeolimarine.com/Volov_Penta_outdrives.htm#VolvoFull

For the OMC
http://www.sterndrive.info/cobra_outdrive.html
Rebuilt $3.3K

$700 difference

I have owned both. Parts like manifolds, trim parts, drive shafts are nearly identical in price.

If you don't work on your own boat, good luck find someone who knows how to adjust the shift linkage properly on a Cobra. I would go through lower shift cables every 2 or 3 years. I got very adept at changing and adjusting these.

Show me a $1000 Ebay Cobra drive that is ready to hit the water that you know that the original owner kept his shift cable adjusted and the dog clutch isn't on its last leg.

In your profile, you say you have run OMC and Volvo. How long have you run each drive?
 

essick5

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Re: 1989 OMC cobra taking on water when beached

thanks to all of you for the info.. i think im going to pull it apart myself and have someone redo the hall and transom... lets assume transom stringers and mount points are all rotten, what do you think im looking at in price just for the hull work.. im pulling the motor myself. Thanks
 

Bt Doctur

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Re: 1989 OMC cobra taking on water when beached

Impossable to determine untill the motor and transom are removed and a complete inspection is made
of the rot. may need a full transom wood replacement.
 

HT32BSX115

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Re: 1989 OMC cobra taking on water when beached

i think im going to pull it apart myself and have someone redo the hall and transom... lets assume transom stringers and mount points are all rotten, what do you think im looking at in price just for the hull work..


Well, that changes everything..

If you have someone else do the fiberglass re-work....... you're getting into a LOT of $$$$.

It simply will NOT be worth it. You will find out when you get the estimate.

AND when you do go for the estimate, BE SURE to tell them to include a floor replacement and stringer/engine mount replacement in addition to the transom replacement.................... BECAUSE, when they discover that it's needed, you may already be into the boat for several hundred dollars.

When you have someone else do the fiberglass work........the amount required to do the job can (and frequently does) end up being FAR MORE than the boat will be worth when you're all done..AND possibly more than you could just go out and buy a good used (newer Merc/Volvo powered) boat that doesn't have any problems.....

Good luck.
 

infideltarget

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Re: 1989 OMC cobra taking on water when beached

gotta agree on the letting someone else do it costing too much thing. until I came to the sandbox, I did everything myself, even if it meant having to learn something new. Now that I am here though, time is a major factor and I must let other s do the work for me. I hate it too. Fiberglass work is very labor intensive, and the hourly rate will be astronomical to redo all of that. Especially if you are on a budget. @ bruceb58...like I said, location. In the backwoods south of TN, there are more OMC available, so therefore the parts are cheaper, and so are rebuilt drives. I was not referring to Ebay drives at all. I wouldnt buy one from there. $4k for the rebuilt drive is better than I found a few months ago when I was looking. Just the parts to rebuild it were that much. Of course all I had was an empty gear case too. My mechanic is very good at working on OMC stuff. He was an OMC certified tech for years before opening his own shop, so shift cables are not a major concern for me. I have run OMC since my first new boat in '88, a Four Winns 160. I have run an OMC Stinger drive for a VERY short time, and I never actually got the chance to run the SX, as it was cost prohibitive to repair/replace. You can see that short story in the four winns section, titled "another project". Everyone has their own preference. Just like Ford v GM. Both are good. Fords are just better ;). If I had two boats side by side and all things being equal except for one having an OMC and one having a Merc, I would have prolly bought the Merc. But that wasnt the case. Its not the case here either. The OP was wanting to fix his hull and transom, not hear about how outdated and obsolete his drive is. He is excited about his new toy and wants it fixed.
 

Black as

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Re: 1989 OMC cobra taking on water when beached

I personally would try and find out where the leak is coming from 1st like Don has said, then establish how and what needs to be done.
 

essick5

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Re: 1989 OMC cobra taking on water when beached

Anyone want to buy a boat!!! thanks guys!
 

HT32BSX115

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Re: 1989 OMC cobra taking on water when beached

The OP was wanting to fix his hull and transom, not hear about how outdated and obsolete his drive is. He is excited about his new toy and wants it fixed.
True......


But he needs to know what he's getting into.

There's a LOT of people out there in radio land that thought they got a swinging deal only to find out that when it's all "fixed' they've got more money in it than it's worth.

Absolutely determine if it can be "fixed' for minimal cost..........but if that requires a new transom, stringers and maybe the aft floor, and he's got to have someone else do it, it may turn out to be better to part out the boat and find something else......
 

Joshua Nichols

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Re: 1989 OMC cobra taking on water when beached

Gotta bilge pump? Put a automatic float on it.. Use the boat this year and sell it mid summer and buy something new.. Hope for no rot..
 

infideltarget

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Re: 1989 OMC cobra taking on water when beached

yep...he absolutely needs to know what he is getting into. but at least with the boat he has now, he knows whats wrong with it. I have seen, and bought too many things (not just boats) and gained nothing but other peoples hidden headaches. Luckily for me, I am able to fix 99% of it, and still sell for a profit. The OP could save his obsolete-but-still-very-good drive set up, and buy a nice hull for a few hundred, do a complete inspection on it before purchase (since it will be mostly empty) so he isnt buying junk, and swap it all over. He could potentially be back on the water for less than $1k and a weekend's work.
 

bruceb58

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Re: 1989 OMC cobra taking on water when beached

Buy a boat and actually spend the effort swapping in an OMC Cobra! You can't be serious?
 

Joshua Nichols

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Re: 1989 OMC cobra taking on water when beached

Could just run the snot outta what he has... Sell it or part it out and buy a new rig that was taken care of..... Find out where it's leaking..
 
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