catfish in exhaust

[keith c]

Question for the mainship brain trust. I may be crazy but here goes. About a week ago a floating dead 4 to6 lb cat fish appeared near my stern. I removed it and didnt think anything of it. 4 days ago I cranked both engines and 3 dead catfish appeared in same area after starting the engines. I return today and crank the yanmars. Bingo another dead fish. Note that my boat has been in the marina for8 years and I have never seen this! The end of my exhausts has a 4 to 6 in open. Are fish entering them and getting trapped.and then being forced out with the exhaust. Also could this probem block the exhaust and cause back flow into the engines? Am I crazy/ pararoid!

 

[Portage_Bay]

You're not crazy or paranoid. Fish, small rodents, all sorts of creatures can decide to make an exhaust port home. For reasons I don't understand once your boat is used by the critters it's hard to change their minds. You'll need to put some sort of barrier on the exhaust ports. Catfish is a new one for me but I don't boat in catfish areas.

Muskrat Otter Exhaust Guards | Guard Your Vessel | Hurley Marine

Muskrat Otter Exhaust Guards install inside the exhaust ports. No penetration to the hull. Installs in minutes. Visit Hurley Marine!

hurleymarine.com

 

[Comodave]

I have used the Hurley guards and found them to be very good. We have some sort of muskrat that lives under the boardwalk so I installed them on our last boat. Our current boat came with them.

 

[JackConnick]

Muskrats, Nutria and others are very prevalent in fresh waters here in the PNW. They can get into the exhaust, make a nest, then chew through silicone bellows and get into the boat and wreck havoc or sink it.
A club member had his boat docked for one night to get hauled the next day and they did the above...
I bought some drain pipe stoppers that plumbers use to seal the exhaust when the engines aren't on.

https://www.amazon.com/dp/B0C7CY66Y7

 

[BruceK]

Were the catfish pretending to be someone else?

 

[Comodave]

Muskrats, Nutria and others are very prevalent in fresh waters here in the PNW. They can get into the exhaust, make a nest, then chew through silicone bellows and get into the boat and wreck havoc or sink it.
A club member had his boat docked for one night to get hauled the next day and they did the above...
I bought some drain pipe stoppers that plumbers use to seal the exhaust when the engines aren't on.

https://www.amazon.com/dp/B0C7CY66Y7

The nice thing about the Hurley guards is that you put them in once and can forget about them. Putting a plug in can be forgotten and also removing them before startup can also be forgotten.

 

[jleonard]

How about installing an exhaust flapper?
I don’t nce had a mouse living in the drain n system of my old Mainship 1. Fortunately it didnt chew anything. It was difficult to get it out. Finally put dish soap into one of the cockpit drain holes and flushed it out with the raw water wash down hose while at anchor.
Wife caught it as it came out and we tried to take it to shore, but it swam the wrong way and didn’t make it very far.

 

[Don L]

wow just when you thought you has seen any thread topic possible

 

[HeadedToTexas]

Hurley for me.

 

[Shrew]

Catfish???? I've never seen a catfish swimming on the surface before. One fish makes its way into an exhaust port is one thing. Several fish repeatedly doing so???

 

[JackConnick]

The nice thing about the Hurley guards is that you put them in once and can forget about them. Putting a plug in can be forgotten and also removing them before startup can also be forgotten.

$50 as opposed to about $300 or more apiece. I just put a piece of tape over the switches. These come out and go in very easily.

 

[snowskierandpilot]

We kept our boat on the Albemarle Sound for several years. It was not uncommon to see water moccasions lounging on the swim platforms of boats basking in the warm summer sun while walking to our boat. Our start procedure is for the wife to call water when she sees water upon start. This beautiful morn setting off for the Outer Banks, waiting for her to call water I heard in a terrified voice "snake!!!". I failed to mention Nancy is definitely afraid of snakes. I went to the stern and saw a very thick and long water moccasin exiting exhaust very slowly! Now the terror from Nancy begins to start. She is hysterical about the snake being in the boat! She is terrified about the boat sinking! Afterall if the snake can get into the boat so can water! I tried to explain in a calm voice that is not possible and the reasons. I am a very blessed man in many ways, as I have aged, Nancy has checked the fluid levels prior to departure. She goes on to explain that she will never go into engine compartment again! I continued to explain to her the snake had nothing to do with a possible sinking to no avail. She generally believes and trusts me, not this time! She asks EVERY mechanic she sees if a snake can get into the engine compartment through exhaust. My back and knees are really sore these days! I pray one day she heals and resumes her pre departure duties. In the meantime, I have developed a serious case of snake loathing!

 

[keith c]

I like the hurley thing but dont like the $300 thing and haul out thing! Having a diver come this week to clean my bottom and check for cats FYI my MS is in Madisonville la on the tchefuncte river

 

[boomerang]

I like the hurley thing but dont like the $300 thing and haul out thing! Having a diver come this week to clean my bottom and check for cats FYI my MS is in Madisonville la on the tchefuncte river

If it's just a catfish you could use anything in the exhausts as a deterrent. I've seen plastic mixing buckets screwed to a stick wedged into the exhaust port to keep out critters but for a fish, a cheap cast net hung over the transom would keep it out. A rodent wouldn't think twice about chewing through a net but not a fish.

 

[keith c]

Good idea! I have an old cast net I am too old to throw and likely cant remember how to throw!

 

[keith c]

Had a diver come out today to clean the bottom on my MS twin yanmar 4 lha's. Catfish backed in both exhaust tubes. Ordering flappers. Any one know the diameter of my exhaust exit tube?

 

[Jklotz]

When I saw the title to this thread, I clicked on it expecting a punchline.

 

[SIBERNUT]

Get a small piece of "hardware cloth", 1/4" openings galvanized screen. Crush a good sized piece over the top of a can sized like your exhaust. Force it in your pipe with jagged ends out, will jam in place.
CHEAP!

 

[CaptTom]

Get a dip net. Every time you start the engine you scoop up a meal. Heck, I'd put out a bunch of small sections of exhaust hose and see if I could catch more.

(Sorry to make light of the situation, but it sounds like you've got it well in hand.)

 

[SIBERNUT]

Poached catfish! YUM !

 

[friz]

Had a diver come out today to clean the bottom on my MS twin yanmar 4 lha's. Catfish backed in both exhaust tubes. Ordering flappers. Any one know the diameter of my exhaust exit tube?

My I/O will never have this issue. As reading through the responses I kept thinking "why not a flapper?". Seems to be the easiest most effective solution. Yes/no?

 

[Kapn]

I've see tetherballs, like the kind hung from a pole on a playground, stuffed in the exhaust port. The line off the ball can tie up to a cleat or rail. The air pressure can be adjusted to fit different size exhaust ports. If you forget it and start the engine it will blow out and dangle from the line or stall the engine if it's too tight.

 

[keith c]

Going to boat today I may be able to messure the exhaust opening from the swim platform I looked up rubber flapper "systems" Not too expensive. Looks like 4in and 5 in are the most prevalent. If anyone has knowledge of the yanmar 4 lha opening please advise. I like the dip net thing. The boat is in the Tchefuntche river ,fresh water. I think the culprits are blue cats which are good tasty etc.

 

[HeadedToTexas]

I have long wondered why some designs have flooded exhaust ports and some have ports above the waterline. I don't mean dry exhaust, but the exhaust port is just above the waterline. Sailboats are common examples. That seems like a far better design as the consequences of a hose or clamp failure sinks the boat in flooded designs (like mine). What is the downside to above the waterline exhaust, just noise and maybe more diesel odor?

 

[hmason]

We kept our boat on the Albemarle Sound for several years. It was not uncommon to see water moccasions lounging on the swim platforms of boats basking in the warm summer sun while walking to our boat. Our start procedure is for the wife to call water when she sees water upon start. This beautiful morn setting off for the Outer Banks, waiting for her to call water I heard in a terrified voice "snake!!!". I failed to mention Nancy is definitely afraid of snakes. I went to the stern and saw a very thick and long water moccasin exiting exhaust very slowly! Now the terror from Nancy begins to start. She is hysterical about the snake being in the boat! She is terrified about the boat sinking! Afterall if the snake can get into the boat so can water! I tried to explain in a calm voice that is not possible and the reasons. I am a very blessed man in many ways, as I have aged, Nancy has checked the fluid levels prior to departure. She goes on to explain that she will never go into engine compartment again! I continued to explain to her the snake had nothing to do with a possible sinking to no avail. She generally believes and trusts me, not this time! She asks EVERY mechanic she sees if a snake can get into the engine compartment through exhaust. My back and knees are really sore these days! I pray one day she heals and resumes her pre departure duties. In the meantime, I have developed a serious case of snake loathing!

Consider yourself lucky. My wife would end my boating life.