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Scupper Leak

local

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DFW, TX
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Yamaha
Year
2005
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AR
Boat Length
23
When I bought my boat last year I, as usual, did some research. Before I could request the dealer replace the old plastic scupper they informed me that they had already done so, with another plastic one. I told them that I would prefer they had installed a stainless version and surprisingly they agreed and replaced the one they had just installed. Mission accomplished!

While using the boat last year I noticed the bilge ran more often that I thought it should. My previous boat had a rotten transom and let a constant 1/4" stream of water in the boat so I really didn't think much of the bilge running every half hour or so otherwise I might have noticed it earlier.

So now I believe that I have a small leak and since I will be taking my boat to the coast next month today I decided to investigate the leak. I go out on the water and stick a borescope down the access ports in the cleanout tray. After a few minutes I found two leaks. One on the thru hull part of the scupper and one on the hose connection of the scupper.

I get the boat home a little frustrated since I had that replaced so I wouldn't have to deal with it and considered going back to the dealer with it but decided it wasn't worth the hassle. After opening up the back and gaining access to the scupper I found the nut was completely loose, I hand tightened it half a turn. The house clamp on the house was in the wrong place and was crushing the hose before the scupper housing.

My question now it since I am this far in should I go ahead and pull the scupper to reseal it to the hull? Should I attempt to find a replacement hose since the end is somewhat damaged from the incorrectly installed hose clamp? Or should I just put some RTV on the hose and install it correctly then seal up the inside of the thru hull fitting and not try to pull the valve out?
 

FSH 210 Sport

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If the scupper is a decent one it should have a silicone gasket on the outside under the mushroom head, see if you can see that gasket. If it is there and in the correct position, apply 4200 sealant around where the nut will sit, and also put some on the flange of the nut and reinstall. Tighten the nut securely but not over tight.

If there is no gasket visible, pull the scupper out and examine everything. Clean up the area where the scupper will seat on the outside and apply enough 4200 to make a good seal on the underside of the scupper, install with the 4200.

Order new hose from west marine as they have Good replacement hose.
 

dgfreeze

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If the new scupper wasn’t sealed with something, I’d definitely recommend sealing it up with 4200. Not 5200. Lol, I used 5200, and it was a mistake. As for the hose, it depends on the damage. If it’s just cosmetic, no biggie, but if the crimped portion has sacrificed the integrity of the hose, replace it. They’re fairly generic, and not too pricey.
 

dgfreeze

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Also, I believe your boat has the same transom as mine, and the outside flange of the scupper has to sit in a recessed section of the transom. Most stainless scuppers have a flange that is just a little too big to sit flat/flush on the outside. Inspect that closely. If it’s not sitting flat, that flange needs to be ground or machined down to a smaller diameter, so it doesn’t ride up the radius of the recessed area. If this doesn’t make sense, let me know, we will do what it takes to make sure you’re sealed up properly.
 

mark_m

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I had my SS scupper turned down so it fit flush into the recessed part. Additionally, I used a tub drain gasket to give it something to seal up properly along with 5200. Agree with @dgfreeze that 4200 is a better choice.
 

local

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All sounds good to me, thanks everyone. The scupper feels fairly well connected to the outside of the hull even when the nut is loose but I was not aware there could be a clearance issue. That would certainly explain the size of the leak, steady stream on the bottom half.
 

local

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I found a significant gap. 20220512_200256.jpg

So I went ahead and pulled the valve to find that it had no gasket at all and it contacted the beveled sides of the hull. After cleaning up the old sealant I fobs there was about a 1/8th inch gap. I ground off the edges that were contacting the hull and now it sits flush without additional pressure.

I will be sourcing a gasket and resealing with 4200 tomorrow.
 

FSH 210 Sport

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Well done!
 

kjr6306

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May as well share what shop installed your scupper valve so we can avoid it like the plague....
 

local

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May as well share what shop installed your scupper valve so we can avoid it like the plague....
Except for this and one other somewhat minor issue I was extremely pleased with the service I recieved buying a 16 year old boat. They fixed multiple items that I didn't even have to ask for including speedometer replacement, transducer, throttle adjustment, replaced worn parts on the Bimini, gave me a new cover, installed sea deck on the rear and more that I cannot remember now.

I am confident that I could have taken it back to them and they would have fixed it. I just didn't want to wait the few weeks it would have taken to get back.

That being said I'm pretty sure there is only one shop in 200+ miles that knows how to work on these boats so it shouldn't be too hard to figure out who it is.

I do plan on using them again hopefully when I buy a new boat in a couple years.
 

local

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I just wanted to follow up on the repair. We finally took the boat for a test run last Thursday with minimal water on a two hour trip, never enough to trip the bilge pump. Yesterday we went out for eight hours and again the bilge did not run once. I'd say that is mission accomplished.

Thank you to everyone who provided helpful info on the repair especially that bit about the scupper not sitting flush I probably would have missed that the first time around.
 

FSH 210 Sport

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Thanks for closing the loop!
 

dgfreeze

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Glad to help, and I’m glad you got her sealed up!
 
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