'84 E10SELCRA Exhaust question

mafhuntfish

Seaman
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Mar 20, 2009
Messages
71
This is the 9.9 with the long extension for use with sailboats. I have it apart to replace the gasket between the powerhead and the exhaust housing. My question is - Does this setup exhaust through the prop or at the base of the extension? Thanks in advance for any & all help .... Mark
 

Rick.

Captain
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Jul 30, 2006
Messages
3,740
Re: '84 E10SELCRA Exhaust question

http://www.sschapterpsa.com/ramblings/OMC/OMC info.htm

http://shop2.evinrude.com/ext/index.aspx?s1=5fb38b35fd598b1ca6978c745c03cec8

Out the prop for the most part. There is a hole in the back of the leg just down form the motor that blows exhaust and water vapor. It works as an exhaust relief when your at low engine speed. Have a look at the two links above. The first is a series of articles that is a must read if you own a 9.9 or 15 OMC and the second will show you the parts diagrams for your entire engine. Enjoy. Rick.
 

Mas

Lieutenant Commander
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Oct 3, 2006
Messages
1,656
Re: '84 E10SELCRA Exhaust question

If your prop is "hollow," then it's through hub...follow the carbon grime.

MAS
 

mafhuntfish

Seaman
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Mar 20, 2009
Messages
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Re: '84 E10SELCRA Exhaust question

Hi - that?s what I thought, but if you look at the photos I?ve included, You?ll see why I?m confused:
Photo 1 shows the top of the lower unit and the bottom of the extension - everything appears to line up like it should:

http://i602.photobucket.com/albums/tt106/mafhuntfish_photos/evinlowerunit/99lowerunit1001.jpg


Photo 2 shows the top of the extension and the bottom of the mid section - here?s where it gets strange. The bottom of the mid has an area where the exhaust comes out and it is sectioned off from the rest of the base. Now look at the top of the extension - it almost looks like it?s missing a part of the casting.

http://i602.photobucket.com/albums/tt106/mafhuntfish_photos/evinlowerunit/99lowerunit1002.jpg


Photo 3 is a closeup of the top of the extension - notice the 2 rear bolt holes where there should be a partition for the exhaust to flow through & come out the prop. This area is wedge shaped, being wider at the top and narrowing down at the bottom. This is allowing the exhaust to exit the rear of the bottom of the extension and the 6 holes in the top rear of the lower unit.

http://i602.photobucket.com/albums/tt106/mafhuntfish_photos/evinlowerunit/99lowerunit1003.jpg


This is my problem - I?m not getting any exhaust out of the prop - (which is hollow) Tell me I?m not braindead ??
 

mafhuntfish

Seaman
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Mar 20, 2009
Messages
71
Re: '84 E10SELCRA Exhaust question

bump - I really need an opinion on this - I need to order parts today & this motor needs to be in the water by April 15th - Thanks in advance
 

Vic.S

Rear Admiral
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May 4, 2004
Messages
4,690
Re: '84 E10SELCRA Exhaust question

I think perhaps I'm brain dead! I cant follow your description and the pictures!

I'm not sure if you are saying that you just dont get any gases out of the prop or whether the thing is designed so that they cant exit via the prop.

However what I do know is that the 6 and 8 Hp versions have the normal exhaust outlet plugged and all the gases escape via two (rectangular) outlets in the side of the extension (picture from an '84 brochure in the clickable thumbnail below)

On that basis I would not be surprised if yours is also designed so that the gases all escape from the outlet at the bottom rear of the extension.
Another picture on the facing page, which I have not scanned, shows gases escaping from the six little holes in the side of the lower unit when going astern (as they would with the non sail version)

I think the sail versions are designed to deliberately put the props deeper in the water than normal. This means that the normal exhaust outlet would also be deep and cause excessive back pressure. Hence the specially placed outlets on the sail versions.

Click the thumbnail and then click the image to get it full size and clear




Taken another look at your pictures now. It appears that the extension is designed so that the gases cannot go down to the prop! It is a special extension for the sail version. The gases escape from the outlet at the bottom of it but can escape from the 6 holes in the side of the LU when going astern. I'm happy hope you are!
 

mafhuntfish

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Joined
Mar 20, 2009
Messages
71
Re: '84 E10SELCRA Exhaust question

Thanks for your reply - everything you've said makes sense. It looks like it's designed to exhaust at the bottom of the extension, but I've never seen that setup before. Just wanted to make sure that I haven't missed something - sorry for the vague description ... Mark
 

Vic.S

Rear Admiral
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Re: '84 E10SELCRA Exhaust question

Just added acopy of lines to the bottom of my previous.

Ive had the 6hp from new. Only recently realised that the "normal" outlet was plugged even though I've had it all off to do the water pump several times!
 

Vic.S

Rear Admiral
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Messages
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Re: '84 E10SELCRA Exhaust question

DSCF0287.jpg
 

mafhuntfish

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Mar 20, 2009
Messages
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Re: '84 E10SELCRA Exhaust question

I know if I didn't learn something new everyday - Life would be pretty boring - Thanks Again .... Mark
 
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