The ultimate leak finding thread <post if you find a new source!>

[Julian]

This is intended to be an ultimate leak finding thread! If you have a leak that isn't covered in this thread, reply and @Julian so I get notified to update it.


First Question:

1. Is the water in the bilge hot? If cold, move to section A, if hot move to Section B.

SECTION A: Your leak is not from exhaust water, so could be from one of the following sources (we've ordered them in a general order of likeliness)

1. Loose or poorly sealed through hull fitting.
   1. This could be the main drain plug itself, shifter cable, bucket cable, speedo, depth finder, or anything screwed into the boat below the water line.
   2. One (not fool proof) way to quickly check for this is to put the plug in the boat while on the trailer and stick a hose in the bilge and fill the stern with water while looking for leaks (don't go to the point of touching the oil filter with water...but you do need some pressure). If this produces a leak outside...voila. If it doesn't, it doesn't rule out these fittings, but make it much less likely.
   3. Visually inspect all the fittings.
   4. Seal with _____(insert preferred sealant here--life caulk? 4200?)
2. Scupper drain (especially for models where this drain is below the water line-24' models built after 20__ (need year) have scupper drains above the water line) may be cracked...often a problem in older 23' Yamaha models...the plastic hull fitting cracks and leaks (photo?). You can't just look at the scupper and think it's "fine", they often crack and look ok, but leak badly. Then they eventually crack off and you have a big hole in your boat!
3. Broken seal around cleanout tray. Reseal with silicone or weather stripping. When you stop the boat quickly, water can get forced up the clean out tray drain tube into the clean out tray. If the hatch isn't sealed water leaks in there, and if the tray edge isn't sealed it will leak there too.
4. Plugs not fully engaged. Water is flowing around them, up into the cleanout port and/or around the cleanout tray to get to the bilge.
5. Intermediate Bearing leak, and another thread on bearing leak
6. Leaks in the fittings at the point where the drive shaft enters the boat. This thread covers this (due to rope ingestion)
7. Anchor locker drain-either has a leak, or the anchor locker itself leaks. This is especially a problem if you drive the boat with a bow full of people through a long no wake zone...it forces water into the anchor locker and fills it with water...which then leaks into the rest of the boat. On some model years the anchor locker drains weren't sealed and allowed water into the hull when the bow was loaded down and driving no wake speeds.
8. If your speedo isn't working and it is a Pitot tube style....check behind the helm for water and connect the hose.
9. If you have ballast bags, check the connector fittings for leaks. There is also a sillcock (valve) on the intake at the through hull that you can close. This would eliminate all but the through hull fitting itself as a leak source on ballast systems.
10. If you are wake surfing and sink the rub rail below the water, the rub rails often aren't sealed well....check there for leaks. Also, the pop up cleats leak.
11. If you beached with the stern very low and waves washing the swim deck, two things could be an issue. One-the rub rails can leak water through, or Two, the clean out tray may not be sealed.
12. Some boats have had leaks in the clean out tube hose at the bottom. This would only leak when the stern was weighed down a lot.
13. Many of our boats don't have drains hoses connected to the cup holders, so when water gets in them it goes right into the bilge. Some boats with swim deck cup holders have this issue. On mine they drain onto the swim deck, but if the hose comes off...then they drain to the bilge.
14. The following thread covers leaks in the clean out tray and rub rails: https://jetboaters.net/threads/need-help-lots-of-water-draining-from-plug-on-17-212x.23345/
15. Do you have a wash down pump or shower tank - check the fitting - some have found them almost completely undone!

SECTION B: If the water in your bilge is hot, then you have a leak in an exhaust manifold.

• Check all the hose clamps and see if any are missing or broken.
• Check for cracks in the manifolds.
• Check for leaks on the intake of your resonator.

The best way to find a leak is to remove the clean out tray and visually inspect for water.

One member used baby powder sprinkled in his bilge as a way to more easily spot where water is coming in. Using your phone with the light on and recording video in the bilge is also a good approach.


Also began an FAQ on leaks

Links to threads on boat leaks:

1. https://jetboaters.net/threads/still-leaking.13046/
2. https://jetboaters.net/threads/surprising-water-leak.13295/
3. https://jetboaters.net/threads/impeller-jam-caused-serious-leaking.7274/
4. https://jetboaters.net/threads/water-leak-from-engine-block.14405/
5. https://jetboaters.net/threads/i-dont-think-water-is-suppose-to-be-there.5919/
6. https://jetboaters.net/threads/water-in-my-bilge.12397/
7. https://jetboaters.net/threads/repa...-a-rope-being-sucked-into-the-impeller.18078/

 

[buckbuck]

Julian, I overfilled a ballast bag this weekend and I think it caused a leak at the fitting on the bag. My bilge ran quite a bit yesterday. Please add that to your list of cold water potential issues.

 

[Julian]

Added your suggestion @buckbuck , and expanded on other items.

 

[tdonoughue]

Suggestions:

A.3. Broken seal around cleanout tray. Reseal with silicone or weather stripping. (you have this as C.4 if beached, but I have had it happen when not beached or low in the back... maybe it goes both places?)
A.4. Plugs not fully engaged. Water is flowing around them, up into the cleanout port and/or around the cleanout tray to get to the bilge.

It also impresses me that all of your C. really probably go in A. They are all non-exhaust sources (e.g. cold water). If our first step is 'is the water hot', then a no answer should put all of A and C in contention. IMHO.

 

[Julian]

Suggestions:

A.3. Broken seal around cleanout tray. Reseal with silicone or weather stripping. (you have this as C.4 if beached, but I have had it happen when not beached or low in the back... maybe it goes both places?)
A.4. Plugs not fully engaged. Water is flowing around them, up into the cleanout port and/or around the cleanout tray to get to the bilge.

It also impresses me that all of your C. really probably go in A. They are all non-exhaust sources (e.g. cold water). If our first step is 'is the water hot', then a no answer should put all of A and C in contention. IMHO.

You are correct on the section C comment.....there are really more choices than just hot or cold water....need to diagram it..... that said...I added your #3&4

keep the comments coming!

 

[tdonoughue]

Ok, so I got a little sidetracked and wound up with this:

The second page is what to do when you get back to home port. Still working on that.

 

[tdonoughue]

Wait. Already an improvement:

 

[rkgdmd]

Anchor locker drain. On some model years the anchor locker drains weren't sealed and allowed water into the hull when the bow was loaded down and driving no wake speeds.

Great thread Julian. I have heard this about the anchor locker before, but I am unsure how water could get to the bilge from that compartment. My anchor locker drain is underwater with a pile of kids in the bow at times, but how is the water making it back to the bilge?

 

[Julian]

Great thread Julian. I have heard this about the anchor locker before, but I am unsure how water could get to the bilge from that compartment. My anchor locker drain is underwater with a pile of kids in the bow at times, but how is the water making it back to the bilge?

That is a great question that I can't answer as I never owned one of the models where it happened. What was said was that on some older models (not heard this in a while), the drain connnected the locker to the outer hull and there was a claim there was space between the two "shells" and water would leak back to the bilge through that space. Now I've looked at my locker and it is just glassed into the bow, so my theory is this....the water would be forced into the anchor locker, and one of two things was happening: 1) water would slosh around over the top of the edges to the locker, or 2) the locker itself was not water tight (my preferred guess) and water would leak out through cracks in the edges or bottom straight back into the boat.

 

[Julian]

Wait. Already an improvement:

Cool diagram....have one addition for you.

Blige pump inopperative? Y- pop clip on the side of the pump and clean out filter screen (should be on your annual maintenance list)

 

[ptwb]

Great thread Julian. I have heard this about the anchor locker before, but I am unsure how water could get to the bilge from that compartment. My anchor locker drain is underwater with a pile of kids in the bow at times, but how is the water making it back to the bilge?

On my 07 230, if you stick your head down into the anchor locker and look up (or use a mirror), you will see that the rear 'wall' of the anchor locker that separates it from the rest of the boat doesn't actually go all the way up. From above, it looks like a separate compartment, but with a mirror, you see that water can spill over. With a fully loaded bow moving forward at no wake speeds, I would open the anchor locker and it would be full of water sloshing around just inches below the 'lip' of the top of the wall. The water was spilling over into the forward storage under the seats.

My issue is the front seat storage and drivers helm storage were always ending up wet. I fashioned a plug for the lower anchor locker drain and found that if the anchor locker stayed dry so did the rest of the boat.

So I made some cardboard templates to try and close off the top of the 'wall'. Then cut some thin plywood. Glue and caulked the whole mess. Now it's mostly waterproof. I'm now 95% dry.

I think what's left is maybe some waves are getting water in via the horn opening.

 

[tdonoughue]

Good add, @Julian. Ok, updated chart:

https://www.lucidchart.com/invitations/accept/27dc64d5-f626-4848-b4ce-60a2a75aa2ee

I also added checking the breaker first. Seems I had some experience with that...

(Got this new drafting tool, er, toy, er, TOOL. Been meaning to try it out... This seemed like as good an opportunity as any. So see if this link thing works to see it.)

 

[buckbuck]

Water in bilge above oil filters? STOP doing sub moves.

 

[Julian]

Good add, @Julian. Ok, updated chart:

https://www.lucidchart.com/invitations/accept/27dc64d5-f626-4848-b4ce-60a2a75aa2ee

I also added checking the breaker first. Seems I had some experience with that...

(Got this new drafting tool, er, toy, er, TOOL. Been meaning to try it out... This seemed like as good an opportunity as any. So see if this link thing works to see it.)

I can't get to this chart here....can you attach it to the forum instead?

 

[OperationROL]

This past weekend, I was in the water while others were on the boat. The first thing I notice was the scupper on my 2015 242 LS was below the waterline. I am sure it is not when there are not people on board or we are moving, but how often does that happen? Seems to me the scupper is still a legitimate area of concern when trying to find a leak even on the boats with the higher scupper mount.

 

[Julian]

Reviving this thread as it got forgotten.

Please give me feedback on the first post so we can further improve it and make it more robust as a place to start when members have leaks in their boats.

 

[Mainah]

Swim deck Cup holder to hull seal and cup holder drain lines throughout were an issue for me. So was the drian plug that a thick o ring solved. I spent a significant amount of time removing and resealing everything. I even added a one way valve drain to the clean out tray. When I pulled my boat out at Harbor Towne after a week in Bimini even with a rough crossing back I had only drops of water come out when I pulled the plug. The cleanout tubes were full. A bone dry hull is possible but takes work.

 

[Pullen724]

Driveshaft tubing not sealed properly. I had a significant lead in rub rail too but I believe that is listed above.

 

[Speedling]

This popped up and i went to the beginning... @Julian brought me way back to visio days. Oh boy.
I know i have the seam along the back deck that lets water in. Every time i retrieve the boat you can see it come in. Makes for a little water every time i pull the plug.

 

[Julian]

Driveshaft tubing not sealed properly. I had a significant lead in rub rail too but I believe that is listed above.

Added this! Thanks!