Exhaust Shutters

[jrsick]

Had myself an overheat, found the shutter cores in the bellows. This picture is looking at the bellows, with the lower unit removed. That's them in the circle. The shift linkage stopped them from getting into the lower unit. I found two, no idea where the other two are, yet. They must be aluminum because they are not magnetic.

[mmwjr]

There are only two. Each has two plates so is that what you are referring to? Did you confirm both sides are missing? Sometimes they break into smaller parts and pass through.

[mmwjr]

Have to ask about your avatar, is that your boat on the hood of a truck?

[Phillbo]

Originally Posted by mmwjr

Have to ask about your avatar, is that your boat on the hood of a truck?

https://www.whec.com/news/town-ontar...affic/4997790/

[jrsick]

The shutters on both sides are gone as result of the overheat. So I have two pieces, and still have two unaccounted for. I've tried everything I can think of to recover the metal frames, including fishing a wire down the exhaust and pulling a rag through. I've borescoped the bellows and don't see anything.
I'm putting it all back together today and will do bucket test then on-water test.
Do you think I should keep searching for the shutter frames if I don't hear any clanging in the exhaust when the engine is running? i.e. take the lower unit off and check bellows again after running the engine a while?

[mmwjr]

So you removed the two pieces of the one flapper as well both mounts and cannot find the other two pieces. Have you verified no pieces made their way into the outdrive? If so they probably went all the way through.

I would install new ones and put it back together. Once started use a IR temp sensor to measure each exhaust side to see if one is getting too hot. Also running on muffs verify water is coming out the two ports on the transom assembly just in front of where the rams attach.

[Ivan Horvat]

Gentlemen, to avoid starting a new topic, I'm writing here.
I'm changing the exhaust and exhaust shutters. Original parts were ordered by engine number, but they are smaller in size. One package has been opened and I can't return it, the second one is still sealed.
Question: If the original part is smaller in size, what should I order?

[mmwjr]

Originally Posted by Ivan Horvat

Gentlemen, to avoid starting a new topic, I'm writing here.
I'm changing the exhaust and exhaust shutters. Original parts were ordered by engine number, but they are smaller in size. One package has been opened and I can't return it, the second one is still sealed.
Question: If the original part is smaller in size, what should I order?

I can’t really say but you may want to email the Mercruiser help site and ask them.

[Ivan Horvat]

Thanks Mike

[Ivan Horvat]

I consulted and they sent me a different part
The catalog number is 807166A1, the correct size has the number 807166A2, but the rubber is marked with the number 807166A1

[mmwjr]

So the left one is the A2 part and is correct size even though it’s marked A1?

[Ivan Horvat]

Yes, the left one is the correct size. On the package A2, and on the part itself A1

[mmwjr]

Originally Posted by Ivan Horvat

Yes, the left one is the correct size. On the package A2, and on the part itself A1

I don’t know what to say about that but at least you got the right part.