omc cobra drive

[brafra]

Help anyone I am going to attempt to install a new boot on my outdrive can anyone give any advice or maybe a breakdown on disassembly on my outdrve it is a 1987 omc cobra outdrive?

 

[Boatin Bob]

Re: omc cobra drive

When you say "BOOT" do you mean the exhaust bellows or u-joint bellows or do you really have a big black rubber boot which would suggest a stringer 400/800?

 

[brafra]

Re: omc cobra drive

Yes it is called the bellows.I was told that the bellows ware out after a while.I want to change them because I have a bad leak and it looks like its coming thru the bottom part of the outdrive.Thanks for responding!!!!!

 

[dick]

Re: omc cobra drive

It may not be your bellows.Did someone look at it or are they guessing?If it is your u-joint bellows and it's been leaking for a while you will be replacing the u-joints and gimble bearing as well.

 

[andrewgroup]

Re: omc cobra drive

This could be something altogether different than what you think. If you can determine if the leak is worse when in reverse or forward slightly above IDLE speed. What I am testing for is to determine if in reverse the leak is worse. this would indicate that the SEAL between the transom and the outer transom plate / shield is leaking and not the bellows as you suggest.<br /><br />Here is what happened to me in a similar situation. The boat had water standing in it despite being elevated and the drain plug removed. A Varmit killed some critters in the boat while in storage and water stood at the back of the bilge area and softened the plywood in the drainhole area. This softening of the plywood caused the lower two bolt holding the inner and outer transom plates. These lost grip and the water was coming up in around the seal. You can expose this problem by going in reverse.<br /><br />You can also do this testing on a friendly ramp that will allow you to keep the boat attached at all point on the trailer and back it into the water. This will allow you to increase the pressure by letting the trailer be a ballist.<br /><br />I have extensive photos of my transom damage and how I fixed this problem using the popular pourable transom casting product from transomrepair.com I would be happy to send some photos of my problem and the procedure I used to repair the localized soft wood problem.<br /><br />If this is your problem, then also try jambing a screwdriver or sharp device into the drain hole playwood after you remove the drainhole plate. If this wood is really soft then you may have a water problem that is not related to bellows.

 

[brafra]

Re: omc cobra drive

Thanks for responding.The leak I have is the same no matter if I have the engine running in forward or reverse or the engine is not running at all but any pictures will help especially on taking the outdrive off.

 

[Lark40]

Re: omc cobra drive

Go to your nearest boat store or dealer and buy a copy of the Clymer 1986-1993 OMC Cobra Repair Manual for about $28. You can also order one by an icon at the bottom of this page.<br /><br />It has very detailed instructions and pictures on replacing the bellows. This is complicated and you need to follow the instructions exactly.

 

[metwrench]

Re: omc cobra drive

Like Boatin Bob asked, Is this the Exhaust or U-Joint bellows ?<br /><br />Exhaust Can be replaced Externally, U-Joint you need to pull the drive off, and he is right..you will be doing Ujoints and Kimble if its been leaking awhile..

 

[tylerin]

Re: omc cobra drive

My opinion is that the only bellows you need to address is the driveshaft bellows. The new exhaust bellows will come perforated anyway. (large slits along the bottom). I believe this allows water to drain. If the driveshaft bellows is bad you have to remove drive and than you might as well replace both.

 

[andrewgroup]

Re: omc cobra drive

When I had my leak that turned out to be the transom mounting seal, I think I could have taken measures to troubleshoot the problem better. I think I should have taken massive amounts of petroleum jelly and smeared it along the outer edge of the transom mounting plate where it meets the fiberglass transom. I would have also tried to put it on the inside of this plate too. Any significant changes in the water flow would have indicated the jelly was affecting the leak and ruled out the bellows or was in addition to. This technique could also be used in and around the driveshaft bellows...

 

[Kenny Bush]

Re: omc cobra drive

Just take a big hammer to it........