OMC Cobra stern drive exhaust question

[wellcraft 185]

Hi all,<br /> After being an outboard person for 15 odd years I now have changed to an I/O and love it but are stumped on something I know nothing about and hope one of you can shead some light.<br />As first stated I have always had outboards and the exhaust has always exited from the centre of the prop but after getting my new toy home and after checking everything proceeded to give it a run in the drive with the muffs on and all ran very nice but noticed an odd thing which was the exhaust was not only exiting from the centre of the prop but also blew out hmmmm how do I explain this? from a "1/4" slit / groove/ ect approx level with the cavatation plate at the rear of the leg (front of the boat ) above the "anode block?".<br />All I want to know is this suppose to happen? and what is the purpose of that opening? I have searched the net and old posts but have had no luck finding the answer .<br />All I can guess is that it is a water entry to help keep the leg cool when moveing?.<br />So can anyone say one way or another.<br /><br />thankyou<br /> mike

 

[cobra 3.0]

Re: OMC Cobra stern drive exhaust question

capt nemo, don't quite know what you are referring to, but take a look at this website and refer to the drawings of your Cobra drive. The newer exhaust bellows have slits on the bottom and let some exhaust come out from there.<br /><br /> http://www.sterndrive.info/id26.html

 

[Lou C]

Re: OMC Cobra stern drive exhaust question

That is the exhaust relief and you will see it exit there if you have the orginal style ex bellows that does not have the slits on the bottom. The ones with the slits will exit all the exhaust water under the transom assembly when running on the muffs. The first time I ran mine I was suprised by this, I was expecting it to come out the prop and the reliefs you are looking at.<br />Believe it or not, original OMC manuals are still available for these and they are much better than the aftermarket, see if you can pick one up.

 

[seamegr]

Re: OMC Cobra stern drive exhaust question

Mike, I noticed that too last year on my 2001 3.0 VP SX. On the muffs, water and exhaust came from I knew not where.<br />I asked my dealer and he said this was normal and I believed him.<br />This spring all became crystal clear while I was installing an active corrosion prevention kit. It bolts to the transom assembly in place of the existing anode. When I took the anode off there was a plastic exhaust block off plate between the anode and the transom assy. The plate and the hole it covered are black with exhaust, the plate has a water drain hole in it. Mystery solved.<br />What is a little strange is that my VP shop manual does not show the plate or make any reference to it. Neither does the illustration in the link in the above post.<br /><br />Greg

 

[wellcraft 185]

Re: OMC Cobra stern drive exhaust question

Thank you very much guys for the replies , I will worry no longer and just get on with enjoying it!.<br /><br />thanks again<br /> mike