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RedNakedness

Nagging leak mystery

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RedNakedness

I'm frustrated and discouraged.  I've had the boat out of the water for 3wks trying to find and fix a leak.  I keep getting 1-3 inches of h2o in the bilge every hour or so. I found numerous problems and fixed.

*** I have found one weird leak coming out of the floor, at the very back of the boat, in a corner underneath the gas tank.  It's as if water is coming out of the floor? *** 

WHAT I'VE DONE-

-removed gas tank,

- replaced fuel lines and vent hose. while I was at it and put a new fuel sending unit in..  

- replaced 4" exhaust hoses (unnecessarily)

-  fixed swim platform bolts that were loose and allowing water to come in and added steel backing plates for the swim platform,

-rebuilt rudder shaft (that was a fun one), no more than a few drips every minute from the shaft packing nut,

-sealed a void in the bow eye bolt and caulked everything I could find that even looked like a risk

-verified no leaks from speedometer hoses

....yet there's still water...i get that  this is an old boat, 1992 Sunsetter, but I shouldn't have water coming out of the floor. This could only mean that water is getting between the floor and the hull, and running to the back of the boat and finding a little pin hole to come out of. One thing I'm wondering...what keeps water from coming into the boat from where the prop shaft enters? Could there be another seal where the prop shaft meets the hull? I can't really see how that is sealed. I put shaft packing rope in the nut closest to the engine but is there more than one place I'm supposed to repack? 

 

 

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formulaben
4 hours ago, RedNakedness said:

I'm frustrated and discouraged.  I've had the boat out of the water for 3wks trying to find and fix a leak.  I keep getting 1-3 inches of h2o in the bilge every hour or so. I found numerous problems and fixed.

*** I have found one weird leak coming out of the floor, at the very back of the boat, in a corner underneath the gas tank.  It's as if water is coming out of the floor? *** 

WHAT I'VE DONE-

-removed gas tank,

- replaced fuel lines and vent hose. while I was at it and put a new fuel sending unit in..  

- replaced 4" exhaust hoses (unnecessarily)

-  fixed swim platform bolts that were loose and allowing water to come in and added steel backing plates for the swim platform,

-rebuilt rudder shaft (that was a fun one), no more than a few drips every minute from the shaft packing nut,

-sealed a void in the bow eye bolt and caulked everything I could find that even looked like a risk

-verified no leaks from speedometer hoses

....yet there's still water...i get that  this is an old boat, 1992 Sunsetter, but I shouldn't have water coming out of the floor. This could only mean that water is getting between the floor and the hull, and running to the back of the boat and finding a little pin hole to come out of. One thing I'm wondering...what keeps water from coming into the boat from where the prop shaft enters? Could there be another seal where the prop shaft meets the hull? I can't really see how that is sealed. I put shaft packing rope in the nut closest to the engine but is there more than one place I'm supposed to repack? 

I think you're talking about the same thing here, but @footndale has a good point.  I'm going to assume you've put it on the water and spent time looking in the bilge for obvious leaks?  Assuming the source of the water is not high up on the boat (like rub rail), the easiest way to check is to put the boat on a trailer and start adding water and see where it leaks out. 

Having said that, I would check the seal and nuts for tightness on both the shaft strut and rudder assembly, and also the tracking fins if they are bolt-through.

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kerpluxal

as @footndale stated.. mine leaked as well.. and it comes in fast... I did not go through the steps of fiberglassing a new piece in which would have been best alternative. I unscrewed, removed old adhesive, applied new marine adhesive and screwed back together.. I had no more leaks during my ownership.

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John I.

Assuming there is no HDS on a '91 SS, I suppose the base of the shaft log could potentially leak. (As could any other hull opening.) 

 

shaft log.jpg

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RedNakedness

Mine doesn't have a box. 

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formulaben

This last winter I was doing some major projects so I had that area about as opened up as can be (aside from removing the engine) so I put a wrench to them and was quite surprised at how many turns it took to fully tighten.  Between that and my new shaft packing I no longer have a good stream of water coming out of my transom plug at the end of the day.

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Falko

Muffler leak?

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RedNakedness

If the base of the shaft log is leaking then it would seem like I'd just need to remove, add new sealant, and reinstall ? Right?  Same would be true for the fins I assume.  I might just do one fin at a time and see if there's any improvement. 

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RedNakedness

It's not the exhaust lines.  I replaced the rubber joining pieces that connect the tips to the fiberglass pipe.  I backed the boat down into the water while it was still strapped to the trailer so that the tips were completely submerged....no leakes from the tips, hoses or pipes.  I did this while the gas tank was removed so that I could clearly see everything.  

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formulaben
1 minute ago, RedNakedness said:

It's not the exhaust lines.  I replaced the rubber joining pieces that connect the tips to the fiberglass pipe.  I backed the boat down into the water while it was still strapped to the trailer so that the tips were completely submerged....no leakes from the tips, hoses or pipes.  I did this while the gas tank was removed so that I could clearly see everything.  

So it wasn't running then?

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RedNakedness

Affirmative.  It wasn't running. Gas tank was removed.  

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formulaben

The amount of water running through the exhaust system at speed is pretty impressive.  A very small leak in the exhaust above the waterline could be doing this, but only leaking while running.

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formulaben

Any update on this?

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RedNakedness

Nothing changes. I still take on water but I can't physically see where it's coming in. I'm about ready to put the water hose inside the boat and try to see where it's coming from. I'm wondering if it could be the fiberglass exhaust tubes. 

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justgary

When @Falko asked about a muffler leak, he meant the fiberglass exhaust tubes.  You should have inspected those when you changed the 4" hoses, but maybe you missed something. 

By the way, I don't think that changing the exhaust hoses was unnecessary.  They do rot out, and I can't think of a better way to sink a boat than with a big hole in an exhaust hose.  I say good job checking that off the list on an old boat. 

How are you using the boat when it gets water in it?  Skiing?  Surfing? 

Also, I'm assuming you have thoroughly checked the engine to make sure you don't have a rusted freeze plug or leaking head gasket.  Water could run down the side or back of the engine and not be very visible.  There's not much room to watch it drip off the oil plug. 

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formulaben

I went back and re-read your original post...did you seal the swim platform bolts with 3M 4200 or something similar?

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RedNakedness

Thanks for keeping the thread alive.  To answer some of the questions...I used 4200 to seal the swim platform bolts and I added a 1/4" plate on the inside of the hull to secure the platform more secure.  No leaks from that location.   

I did notice that several of the through hull bolts for the fins were not tight.  I removed, caulked, and tightened all through hull bolts. I was hopeful that was going to be the fix...nope.  The water seems to come in faster when surfing. 

Edited by RedNakedness

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dalt1
3 minutes ago, RedNakedness said:

Thanks for keeping the thread alive.  To answer some of the questions...I used 4200 to seal the swim platform bolts and I added a 1/4" plate on the inside of the hull to secure the platform more secure.  No leaks from that location.   

I did notice that several of the through hull bolts for the fins were not tight.  I removed, caulked, and tightened all through hull bolts. I was hopeful that was going to be the fix...nope.  The water seems to come in faster when surfing. 

Does it come in any vents on back of boat? When surfing my 12 VLX it always gets water in the rear vents on corners when stopping and roller hits back of boat.

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justgary

I didn't see where you resealed under the rub rail.  You may be forcing water through the gap between the top and bottom hull shells.  They try to seal that at the factory, but sometimes a little gap happens.

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formulaben

Have you ensured the shower (if installed) is off?

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Woodski

@formulaben:  good document.  FYI - a raw water pump delivers pretty close to 10 gpm per 1,000 rpm so the flow rate will depend on engine RPM and it is pretty linear since a positive displacement pump.  

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RyanatJongbloed

I have a 2006 247 and after a year I finally found my leak.  Prop Shaft Strut was loose. I put a screwdriver on them and only 1 bolt was tight.  All the others just spun in place. 

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