OMC Cobra (1986 Carrera) outdrive leak

WAM

Recruit
Joined
Jun 22, 2009
Messages
2
We have been gifted a 1986 Carrera, which has a OMC Cobra stern drive. After our first Summer outing I found the boat was taking on water at a slow to moderate rate. Well I believe we have located where the leak is coming from by slowly dropping the trailer and boat in at the launch. Plug is good, and there is no leak until the water level is above the first studs. Then there is a noticebale leak coming from one of the studs. It does appear to be isolated to one side only. We just finished troubleshooting last night. I have not attempted to even tightent that bolt yet. I am new to this and I don't want to make things worse. Should I start with (to me) what would be the obvious and tighten the bolt? Do I need a torgue wrench? If simply tightening doesn't do the trick, then is there an easy (don't laugh) way to seal around the studs? I will appreciate any input that you have.
 

danond

Lieutenant Junior Grade
Joined
Jun 11, 2007
Messages
1,118
Re: OMC Cobra (1986 Carrera) outdrive leak

If it's your gimbal housing seal, plan on pulling the engine and drive to fix this issue. Leaking gimbal housing seals require everything to be removed to replace.

It's rarely a loose bolt, but it can't hurt to check. Don't over-tighten it. It only needs to be tight, not smashing the transom or stretching the bolt tight.
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,610
Re: OMC Cobra (1986 Carrera) outdrive leak

it is also possible you have a rotten transom. Keep your fingers crossed that it isn't.
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,233
Re: OMC Cobra (1986 Carrera) outdrive leak

it is also possible you have a rotten transom

Ayuh,... That would be My Guess,.. Those bolts Don't just loosen by themselves...
 

WAM

Recruit
Joined
Jun 22, 2009
Messages
2
Re: OMC Cobra (1986 Carrera) outdrive leak

Thanks everyone. I will keep my fingers crossed. I will also inquire (boat has been in my wife's family its entire life) if they recall if or when the lower end was rebuilt. I appreciate the pointers.
 
Top