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Muskrats...fresh water boaters take note

Posted: May 10th, 2017, 9:50 pm
by Lyndon670
Folks,

Every time - literally every time - before I start my engines, I go into my engine room for a pre-start inspection. I check oil, belts, hoses, connections and everything else.

last fall as I was getting ready to start my boat for the final trip over to the Travel Lift, I did exactly this. I then fired the mains up and checked all of the insturments to make sure all in order. I then went onto the dock to get ready to do line handling with my wife still on the boat. As we were waiting for the boat to warm up and chatting, I noticed 2 of the thru hulls for my bilge pumps spraying water out - like fire hydrants had been opened. My 506 has very large pumps and can move a lot of water, but this was the first time that I actually saw them in action.

I quickly boarded the boat and opend the hatch into the engine room and saw that my port wet exhaust elbow had grenaded right at the elbow. Water was quickly filling up the bilge - the stringers in the 506 stand about 14"tall and the water was quickly approaching this level on the port side.

I ran back up to the bridge and shut the engines down.

When I got back into the engine room, my pumps had doe a great job of evacuating all of the water. I can tell you that even if you think you have clean bilges, fill them up with water and pump them out - they aren't as clean as you think.


What I saw was that the elbow had been "scratched" through by an animal. It had swam through the water level exhaust, through the muffler and attemped to get into my E/R by clawing through the elbow. He did not get through, thankfully. I believe that the initial exhaust pressure combined with the cold water blew the weakend elbow right at the bend. See the picture attached.

I spoke with my marina and they advised me that they had lost a 55' Ocean Alexander the same way 3 years prior, sank right at the dock.

I have since replaced the elbow and have taken some precautions. I drilled small holes in my stainless exhaust ports and looped stainless mechanics wire through to create a "cage".

If you are a fresh water boater - be wary of this. Without pulling off your hoses, there is no way of inspecting them.

Just something to think about. I can't imagine this happening in the middle of Gbay with my engines running at 2200rpm. It would make for a very bad day.

Re: Muskrats...fresh water boaters take note

Posted: May 10th, 2017, 11:02 pm
by Viper
That is a must in some areas for sure. Glad nothing major happened. Could have been so much worse.

Re: Muskrats...fresh water boaters take note

Posted: May 10th, 2017, 11:16 pm
by tomschauer
Lyndon, sorry this happened, but glad it happened in such a circumstance where you were able to notice it immediately. As you mentioned if you were under way when the elbow blew out and not noticed for several minutes or more, it could have been a bad situation!

Re: Muskrats...fresh water boaters take note

Posted: May 11th, 2017, 1:12 am
by dsolo
WOW! I will add this inspection to my list to look for. Thanks for sharing. Dan

Re: Muskrats...fresh water boaters take note

Posted: May 11th, 2017, 6:46 am
by Midnightsun
Glad it worked out and a great post for a reminder to all. They also have a tendency to chew up bellows on stern drive units which is one of the reasons you should always leave the drive down. Never seen it but have heard of it. On my previous boat, my underwater lights stopped functioning and also my depth readings right close to end of season. Turns out those pesky buggers chewed through some underwater electrical wires which I noticed during winter commissioning, at least they got the timing right on that one. The exhaust on my Volvos is underwater and grated so I am protected and the secondary rear above water line exhaust is much too small for anything but a fat mouse to get into.

Re: Muskrats...fresh water boaters take note

Posted: May 11th, 2017, 7:24 am
by Viper
Midnightsun wrote:Source of the post .... They also have a tendency to chew up bellows on stern drive units which is one of the reasons you should always leave the drive down. Never seen it but have heard of it.....

+1
I see it all the time. I did a bellows job once and when the owner went to the boat for the weekend, he noticed water leaking into the bilge. He called me and said I must have installed the bellows wrong. Upon inspection, we found a large hole and could actually see the teeth marks.

Had the same thing happen with replaced Leveler Insta-Trim tab hydraulic lines. Customer went to test it the first time he went to the boat and got a large oil slick. He hauled out the boat and had his automotive mechanic look at it. Again, got a phone call saying that I screwed up as the reason for the leak was because I used hose clamps and that shouldn't be done on a hydraulic system. Wanted me up there right away while they waited. Dropped everything, went up, and the first thing I did was operate the tab and got a stream shooting sideways out the middle of the line. Took a close look and again you could see the teeth marks in the hose. The auto mechanic then asked why I used hose clamps on a high pressure hydraulic system to which I replied that if he was familiar with this marine system, he'd know it's not high pressure (relatively speaking) and that the manufacturer states it's okay for clamps, in fact that's what's used at the pump end. He asked me to replace the line again, I said get your automotive mechanic to do it, gave him a nice invoice for the service call, and walked away! If he was nice about it I would have handled it differently but he had already burnt that bridge. (My rant for the day ;-) )

The other thing I see often is bird nests and a bunch of feathers being blown out the exhaust at first startup in the Spring.

Gotta love the wildlife!

Re: Muskrats...fresh water boaters take note

Posted: May 11th, 2017, 10:58 am
by jcoll
Viper wrote:[quote="[url=http://www.carveryachtowners.com/memberlist.php?mode=viewprofile&u=1896]]Source of the post He asked me to replace the line again, I said get your automotive mechanic to do it, gave him a nice invoice for the service call, and walked away! If he was nice about it I would have handled it differently but he had already burnt that bridge. (My rant for the day ;-) )!
[/quote]

Having been in the auto repair business quite a few years, I understand and agree with your position 100%. But - did he pay it? (I would probably have doubled it.)

Re: Muskrats...fresh water boaters take note

Posted: May 11th, 2017, 6:41 pm
by Viper
Ya he paid but understood why I didn't want to do the job the second time and apologized later. We're all good now and I've done more work for him since but he knows his boundaries now!

Re: Muskrats...fresh water boaters take note

Posted: May 12th, 2017, 12:28 pm
by bud37
Lyndon670 wrote:Source of the post Folks,

Every time - literally every time - before I start my engines, I go into my engine room for a pre-start inspection. I check oil, belts, hoses, connections and everything else.

last fall as I was getting ready to start my boat for the final trip over to the Travel Lift, I did exactly this. I then fired the mains up and checked all of the insturments to make sure all in order. I then went onto the dock to get ready to do line handling with my wife still on the boat. As we were waiting for the boat to warm up and chatting, I noticed 2 of the thru hulls for my bilge pumps spraying water out - like fire hydrants had been opened. My 506 has very large pumps and can move a lot of water, but this was the first time that I actually saw them in action.

I quickly boarded the boat and opend the hatch into the engine room and saw that my port wet exhaust elbow had grenaded right at the elbow. Water was quickly filling up the bilge - the stringers in the 506 stand about 14"tall and the water was quickly approaching this level on the port side.

I ran back up to the bridge and shut the engines down.

When I got back into the engine room, my pumps had doe a great job of evacuating all of the water. I can tell you that even if you think you have clean bilges, fill them up with water and pump them out - they aren't as clean as you think.


What I saw was that the elbow had been "scratched" through by an animal. It had swam through the water level exhaust, through the muffler and attemped to get into my E/R by clawing through the elbow. He did not get through, thankfully. I believe that the initial exhaust pressure combined with the cold water blew the weakend elbow right at the bend. See the picture attached.

I spoke with my marina and they advised me that they had lost a 55' Ocean Alexander the same way 3 years prior, sank right at the dock.

I have since replaced the elbow and have taken some precautions. I drilled small holes in my stainless exhaust ports and looped stainless mechanics wire through to create a "cage".

If you are a fresh water boater - be wary of this. Without pulling off your hoses, there is no way of inspecting them.

Just something to think about. I can't imagine this happening in the middle of Gbay with my engines running at 2200rpm. It would make for a very bad day.


Lyndon, Wow, had some chewing away at a previous boat and had to make some guards....stainless rod in a grate pattern.....I am given to understand that the little darlings are quite allergic to lead......

Re: Muskrats...fresh water boaters take note

Posted: May 12th, 2017, 2:13 pm
by jcoll
Viper wrote:Source of the post Ya he paid but understood why I didn't want to do the job the second time and apologized later. We're all good now and I've done more work for him since but he knows his boundaries now!

Glad to see he came around. That's probably the best possible outcome.