Alpha 1 gen 2 unknown part

[tech62571]

hoping someone can identify this.
it fell to the ground when I separated the lower half to replace the impeller

cant figure out where it goes

[mmwjr]

See Mercruiser manual #14 for the Alpha drive. I believe it’s the water pump dam. Should fit into a channel behind the pump housing.

[tech62571]

I have a rubber filler plug there

[tech62571]

I cant find that part anywhere on the alpha 1

[jrsick]

That looks like the spine of an exhaust shutter.

[mmwjr]

Originally Posted by jrsick

That looks like the spine of an exhaust shutter.

Good call. One or both (depending on what engine you have) of your exhaust shutters needs to be replaced. These are to prevent backwash from going up the exhaust and into the engine.

[tech62571]

thanks guys.. that one stumped me when I heard it hit the ground

is that something I should repair before putting in the water again?

is this a fix I can do myself?

I have a 2006 - 3.0 mercury

[mmwjr]

I would repair it, only one with the 3.0. Go to Documents of this site and get the Mercruiser Alpha manuals for the 3.0 and Alpha for directions.

[jrsick]

The exhaust shutter will prevent water from coming into the engine via the exhaust.
As a general rule, never let your wake catch up to you and slap the back of your boat. At least, not without some power on the boat. But if you do catch a wave astern, the exhaust shutter will prevent water intrusion.
While you have your exhaust apart, you can also check your risers for corrosion.

[tech62571]

wow.. you guys really know your stuff
appreciate all your help.

[mmwjr]

Here is a picture for a V6 or V8 engine, yours is similar but only one tube. #7 is the flapper.

[jrsick]

Let us know if you plan on tackling this project, we can give you some tips to hopefully make it easier for you. Not a particularly difficult task, but there is some tugging and prying involved.

[tech62571]

thanks guys.. I am going to give it a try.

[jrsick]

I used an automotive trim tool kit and soapy water to remove and reinstall my exhaust.
I recommend taking the stainless bands completely off, they will get in the way if you try to just loosen them.
Use a long, flat trim tool to break the bond between the rubber exhaust tube and the metal riser and exhaust elbow. Use the trim tool to work the soapy water between the rubber and metal exhaust components. Keep the soapy water handy, you'll need it when you put it back together.
Are you going to remove the manifold and riser also? Don't forget to get gaskets if you do.

[tech62571]

thanks for the advise.
I ordered the parts today.

I usually use a radiator pick tool for hoses but ill get a set of the trim tools as well.

do I need to remove the manifold and riser? I wasn't planning to

[jrsick]

You don't need to remove the manifold and riser to replace the exhaust shutter.
The metal components of the exhaust (exhaust pipe, elbow, and riser) are much closer together than they appear in the parts manual. Mine had 1/4 inch or less gap between them.

[tech62571]

ok thanks a lot.
guess ill have to see when I get in there