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joseph m. hahnl
03-15-2010, 07:00 PM
I'm having trouble finding the exhaust block off bellows for the out drive leg. Any one have any links?

gcarter
03-15-2010, 07:49 PM
Do you mean the one located inside the transom directly under the drive shaft?
The last time I checked, it was a plate.
But maybe I'm thinking of something else.

gcarter
03-15-2010, 08:07 PM
Maybe like this?
Look at the plate, #10.

http://www.dougrussell.com/partscatalog/images/CRUISER/14295/40.gif

BlownCrewCab
03-15-2010, 09:01 PM
if you use the blockoff plate you want to remove the exhaust bellows from the transom assembly, this will let it induce air into the void punched in the water by the drive. if you use the blockoff and leave the bellows then theres a vacuum or low pressure behind the drive. if your not looking for every available MPH don't worry about it, but if you are looking for the speed there is a little to be found there.

epatti1062
03-15-2010, 09:09 PM
I had trouble finding one for a alpha. I made mine out of 1/4 aluminum and wasn't that hard took about an hour. Tim

mrfixxall
03-15-2010, 11:10 PM
i have a few # 10 's somewhere! ill have to find them,let me know if you need one..

joseph m. hahnl
03-16-2010, 03:57 PM
Do you mean the one located inside the transom directly under the drive shaft?
The last time I checked, it was a plate.
But maybe I'm thinking of something else.



No, not that one. I dont have a hole in my transom for through the prop exhaust. The bellows is only there to keep water out of the out drive


I need the one that goes on the Leg. It would not be a plate it would be a rubber cap.

http://www.mercruiserparts.com/images/CRUISER/818183.91/11.png

gcarter
03-16-2010, 04:31 PM
Uhhhhhhhhhhhhhhh..........
Are you reallly sure?
I've not seen an Alpha like that.
You do have a hole in your transom as all Alphas and Bravos use the same cutout.

silverghost
03-16-2010, 05:33 PM
I'm not sure we are all on the same wavelength here. We could be talking about different caps.
Not really sure what outlet or bellows you ask about?
In any event.
Any good plumbng supply carries JACO rubber pipe caps from 3/8"up to 8".
If that's what you really need?

mrfixxall
03-16-2010, 05:45 PM
No, not that one. I dont have a hole in my transom for through the prop exhaust. The bellows is only there to keep water out of the out drive


I need the one that goes on the Leg. It would not be a plate it would be a rubber cap.

http://www.mercruiserparts.com/images/CRUISER/818183.91/11.png

U-joint bellow??? if no then im lost........we need the correct term..

gcarter
03-16-2010, 05:47 PM
The inside of your gimbal housing looks just like this. There's not more than $0.02 cents worth of difference in an Alpha or Bravo housing as far as appearances go.
So look at the flange where the exhaust bolts on.........that's where the block off plate goes.
On the far side is a tubular part of the casting that is where the exhaust bellows clamp on.

http://www.donzi.net/forums/attachment.php?attachmentid=51066&stc=1&d=1253905792

gcarter
03-16-2010, 05:54 PM
Here's another picture of the inside of the housing w/the plate bolted on.

http://www.donzi.net/forums/attachment.php?attachmentid=31112&d=1187208866

joseph m. hahnl
03-16-2010, 06:24 PM
Yes George I under stand what you are saying. there is no hole drilled in the transom fore the exhaust bellows. When looking through the exhaust bellows towards the transom. NO Hole through the transom from outer plate to innerplate. It is all Glass.

Fix: I"m not talking about the U joint bellows. The picture was for reference to indicate thate the transom area is not what I am looking for.

Ghost: Yes exactly I need a Rubber cap that will go on the out drive leg.

Let me ask it this way

You put a block off plate on the inner, Now there is no need for a stretch and crimp exhaust bellows. What do you put on the out drive to keep water from entering the lower unit?

gcarter
03-16-2010, 06:40 PM
You put a block off plate on the inner, Now there is no need for a stretch and crimp exhaust bellows. What do you put on the out drive to keep water from entering the lower unit?

If you go back and read Michael's post, you really do want water/air to enter the drive. It was a well reasoned idea. There's a very large hole in the prop and the wash coming off the blades does generate a very strong vacuum, filling that vacuum does improve your performance.

If the design of the through prop exhaust were better w/increased area and fewer bends, at speed the engine would experience a mild supercharging effect due to that vacuum.

joseph m. hahnl
03-16-2010, 07:57 PM
If you go back and read Michael's post, you really do want water/air to enter the drive. It was a well reasoned idea. There's a very large hole in the prop and the wash coming off the blades does generate a very strong vacuum, filling that vacuum does improve your performance.

If the design of the through prop exhaust were better w/increased area and fewer bends, at speed the engine would experience a mild supercharging effect due to that vacuum.

George:The shift rod runs through that port. I would be worried that the lower unit would fill with water.

gcarter
03-16-2010, 08:18 PM
Yep, indeed it does go through the port, on every Gen I or II ever made, including R's and their predecessors.
It's really OK.

BlownCrewCab
03-17-2010, 05:58 AM
Even if you where using your thru hub exhaust, when parked that whole cavity from the hub all the way up to the water (surface) level is full of water, when you start the motor it pushes it out. in this case your not pushing it out with exhaust..

joseph m. hahnl
03-17-2010, 02:41 PM
Even if you where using your thru hub exhaust, when parked that whole cavity from the hub all the way up to the water (surface) level is full of water, when you start the motor it pushes it out. in this case your not pushing it out with exhaust..


Okay :No worries then. Yah!!! I kind of thought about that after :bonk:
That makes it a lot cheeper to replace the bellows:wink:

gcarter
03-18-2010, 10:36 AM
Joe, I was just out in the shop looking at my gimbal assembly......
If you notice, the exhaust boss projects inside the cutout, so yours must be cutout also. Also the trim pump lines run through the small oval hole in the bottom of the housing.
I suspect what you see through the outside of the housing is the backside of the blockoff plate.
Hope this helps.

http://www.donzi.net/forums/attachment.php?attachmentid=54409&stc=1&d=1268926450

http://www.donzi.net/forums/attachment.php?attachmentid=54410&stc=1&d=1268926450