Hmm, appears chunk of fiberglass hull was left inside exhaust box - for 16 years

[kmdigital]

I bought a 98 Four Winns Horizon QX last July. It's very clean and very low hours, and other than some scratches on the sides of the hull from loading or something like that, it looks nearly new. The gimble bearing and bellows were replaced a few years ago per the maintenance records, and are in good shape, but last night I decided to pull the drive just to verify and to grease the u-joints.

When I looked down the exhaust bellows there appeared to be something, almost like a flapper, about 2/3 blocking the hole. I used a 1/4" rod to push on the edge to see if it would open and it swiveled and fell out inside the exhaust box. I moved it around a bit and shot the pictures below down the exhaust bellows. After moving it around a bit, I'm convinced that it's a section of the hull that was cutout through the transom. It must have been in there since 1998, and it's amazing that it didn't completely block the exhaust port, preventing the engine from even running. It's amazing that the quality control at the Four Winns factory was so poor that someone could use a hole saw to cut the hole and not verify that the slug was removed, or at least that's my theory.

The question is, how do I get it out? It's too large to come through the transom assembly, and I really don't want to remove it just to get it out if I don't have to. Is there any way to reach it from inside, inside the exhaust box?

My thought is to use some sheet metal to protect the exhaust bellows, and then take a 1/4" rod, bend a hook in the end, heat it red hot repeatedly, and reach in through the bellows and see if I can cut/melt a slot down the middle of this piece until it gets most of the way through, after which it should scissor and collapse enough to be able to fit down through the transom hole.

Is this likely to work, or does someone have a better idea?

The boat has the 3.0 engine, M# 302CPBYC, S# T1307301, drive is M# 3868814, S# T0818545, which I think is the Penta SX-M.

Thanks for any suggestions/help

 

[muc]

~~Looks like your engine overheated at some point in the past.
That is most likely an exhaust flapper and needs to be removed.
Volvo doesn'™t sell these (flapper) anymore and has published a service/parts bulletin about this.

 

[diverpat]

I had the same thing happen on my 5.7 with the SX drive, I was able to take off the anoid on the bottom and and it fell out, it does look like the flapper, they say make sure your highest point on the exhaust is at least 15 inches above sea level when your boat is in the water.

 

[kmdigital]

~~Looks like your engine overheated at some point in the past.
That is most likely an exhaust flapper and needs to be removed.
Volvo doesn'™t sell these (flapper) anymore and has published a service/parts bulletin about this.

Hmm, are you saying that this was supposed to be inside there and connected to something? It's quite rough on the one side while smooth on the other, which tells me that it's a piece of fiberglass, or at least I thought it did. What does the service bulletin have to say about this?

I can't tell that anything was ever overheated. All the paint is still on the engine, no burned or darkened areas, etc, so if it got hot, it wasn't by much. It doesn't use oil and ran good last year, though I wonder how with the exhaust mostly blocked.

​It's inside the hull area, as far as I can tell, so I don't know that it's accessible via the removing an anoid under the transom bracket, but maybe it is accessible. I will check, as that would sure be easier. Thanks

 

[skydiveD30571]

Here is the bulletin:

 

[skydiveD30571]

Double post.

 

[kmdigital]

Here is the bulletin:

There's nothing attached or linked to this post. All I get is an image of a broken link... Sorry

 

[Sparkinator]

Mine were melted and lodged in the exhaust of the drive. They made it through the bellows and I found them when I removed the drive. They were melted and stuck in the bottom of the drive. They looked and felt like plastic.

These flappers were in the exhaust risers just behind the exhaust manifolds and were there to prevent water from coming back into the block from water coming back in through the exhaust ports in your prop, or if the exhaust bellows came loose, water could backfill from there. They worked kinda like the exhaust flap you see on old tractors. They close off when the engine isn't running, but open up to allow the exhaust to escape. Eventually, Volvo decided the risk of water intrusion wasn't great enough to continue installing these in there exhaust systems.

 

[kmdigital]

Mine were melted and lodged in the exhaust of the drive. They made it through the bellows and I found them when I removed the drive. They were melted and stuck in the bottom of the drive. They looked and felt like plastic.

These flappers were in the exhaust risers just behind the exhaust manifolds and were there to prevent water from coming back into the block from water coming back in through the exhaust ports in your prop, or if the exhaust bellows came loose, water could backfill from there. They worked kinda like the exhaust flap you see on old tractors. They close off when the engine isn't running, but open up to allow the exhaust to escape. Eventually, Volvo decided the risk of water intrusion wasn't great enough to continue installing these in there exhaust systems.

Oh, okay. I wondered how they could have left it inside there. I guess they weren't fastened very well, and it certainly has the risk of completely blocking the exhaust system. Being a 4-banger, I suppose mine has only one while a V-type engine would have two, one on each side. I guess my idea of heating a rod to melt it enough to get it out should work if I'm careful then.

thanks