87 omc 4.3 cobra transom leak

rschaupp

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Jan 15, 2008
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I have located the leak on my omc outdrive. It is around the bottom of the outdrive mount, it starts leaking when the outdrive is submurged only 2 inches in to the water. I understand that the motor must be removed to remove the inner and outer outdrive plates. Is it worth a try to loosen the plates apply some sealer between the outer plate and the transom? If I remove the engine, where can I get a oem OMC manual? The selog manual I have gives very little info regarding this job.
 

rodbolt

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Sep 1, 2003
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20,066
Re: 87 omc 4.3 cobra transom leak

if its the transom seal thats leaking odds are high the transom is rotten.
ya need to remove it all for inspection. when replacing the seal ,best I recall, you use scoth grip rubber adhesive to seal the seal to outer shield and no sealent on the seal to transom area.there is another spec on transom seal area flatness as well as transom thickness but it escapes memory.
 

Bondo

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Re: 87 omc 4.3 cobra transom leak

if its the transom seal thats leaking odds are high the transom is rotten.

Ayuh,........ I Agree........

This isn't a place for Short-Cuts,.......

Your boat has Major Problems that Need to be dealt with.......
 

Gary H NC

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Re: 87 omc 4.3 cobra transom leak

here is an original OEM service manual,its a 1986 but it should have everything you need in it.You can email the guy (Jon) and ask him if he has the 1987 edition,he probably does.I have bought several from this seller and they are worth every penny!
Get the real manual,you will need it!;)
"http://cgi.ebay.com/ebaymotors/1986-OMC-COBRA-STERN-DRIVE-ENGINE-REAL-SERVICE-MANUAL_W0QQcmdZViewItemQQcategoryZ26453QQihZ010QQitemZ200177044211"
 

rschaupp

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Jan 15, 2008
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Re: 87 omc 4.3 cobra transom leak

thanks for the help. I found a 87 oem manual on ebay,and purchased it right away. I hope its the the right one. I am not looking forward to removing the whole drive and engine, I have installed a few engines and transmissions in cars trucks and tractors, but no boats, so I will probable get it done.
 

Bondo

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Re: 87 omc 4.3 cobra transom leak

I am not looking forward to removing the whole drive and engine, I have installed a few engines and transmissions in cars trucks and tractors, but no boats, so I will probable get it done.

Ayuh,........

Once you get a Really Good Look at it,......
You'll see,..... Working on Boat drivelines is Much, Much Easier than cars, trucks, or tractors.........
 

rodbolt

Supreme Mariner
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Sep 1, 2003
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20,066
Re: 87 omc 4.3 cobra transom leak

Bondo is right
it can be more aggrevating but I rarly get kitty litter and burned ATF in my hair and down my back anymore :).
couple that with the Cobra is one of the easier packages to remove its not bad at all.
had my fill of the automotive world years ago.
now if my truck is broke there is a dealership for that.
 
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