A bit of water... of course...

[Speedling]

Ok, so ever since I bought the boat a couple years ago, I"ve had a little water coming in from somewhere. Enough to turn the bilge on after say 3-4 hours of sitting. That's with no one going in or out. I know it's not the cleanout hatch, and we didn't have any ice or anything in a cooler today. Still had it turn on.

Bad scupper? Where the shaft comes into the boat?

Having a hard time finding ways to check either one out and inspect for leaks. Even thought maybe the exhaust where it comes out of the boat, but I just haven't found anything yet. Any ideas?
It's not much, but when you're a speed nut like myself, having 5 gallons of water isn't my idea of speed mods...

 

[Murf'n'surf]

Is the water hot or lake temp?

Run your hand under everything in the engine compartment trying to find a sign of water. I've seen some small leaks in exhaust connections and in the smaller rubber cooling hoses.

Have you filled your engine and lower bilge area up with water and looked for a leak on the outside of the hull?

 

[Speedling]

I never see the water until it comes out the bilge really.
There is just a little bit from time to time under the center area of the engine bay.
When I take the boat home, park it, and jack the front up off the hitch, it always has more that pours out. I just haven't figured out why or where it's coming from.
I haven't filled it up specifically for this because i had an issue with the fiberglass being worn all the way through up front. I haven't painted it yet, but I don't think it should leak now that I have repaired it.
Maybe if I park it up hill in the driveway and tell the wife to start cleaning I can leave the plug in and wait to see if it leaks. she usually just leaves the hose run while doing her cleaning. Although, then again, this would just come out the scupper, no?

I have checked all around the engines that I can see and there doesn't seem to be anything wet. Perhaps once it gets going faster? Could the increase in pressure cause it? Maybe a leak in the high speed pee hole tube? I would have to have someone else drive, but my wife is usually holding a child, lol

 

[Magic]

@Murf'n'surf has the right idea. If its not leaking from the engine, you will probably be surprised where it IS leaking from. We had a small leak from a screw mounting hole for the speedometer paddle-wheel, and a leak in the pump housing. Corrected both of those issues, and kept an eye on the grease in the intermediate bearings, and not a drop comes out when we pull the drain plug, even after a few days on the lake!

Water-sports days are different, we usually get a couple of gallons out of the true bilge, but never anything in the engine compartment. We do still make sure the bilge pump works when we clean the engine compartment and let the pump evacuate the water.... Do not want to tempt fate!!

 

[jdonalds]

I don't get enough water in the boat to cause the bilge pump to come on, but I do have 1 to 3 (guess) gallons of water that drains from the transom plug at the end of most rides. I've determined it is most likely water getting by the plugs, filling the tubes, and spilling into the bilge.

I used a hose to put enough water into the boat so I could see where it leaks out - quite a lot of water. Then I drove it to a hill and watched where the water came out. Nothing. Not a drip from anywhere. It took about 10 minutes on that hill to drain all of the water out through the transom plug.

I replaced my plastic scupper with the recommended stainless steel version but I did it soon after I learned these were breaking and mine wasn't broken. I started a poll on the other jet boat web site and 17% of those who replaced their plastic version found them broken.

Some will say water coming up onto the swim deck will get into the boat. That could be the source of some of your water. It's not on mine.

Several have found a variety of small leaks, some of which have been mentioned in this thread already. Sources mentioned have been on the bond line (where the lower hull and the top section of the boat are joined), or small through-the-hull fittings.

 

[Speedling]

So, I double checked the basic things quick while waiting for the wife to get ready to go to the mother's day party...
I believe my scupper is cracked, in almost a perfect circle on the inside, which made me think it was part of the casting!!! so THAT's getting ordered right now...

 

[jetboater4life]

So, I double checked the basic things quick while waiting for the wife to get ready to go to the mother's day party...
I believe my scupper is cracked, in almost a perfect circle on the inside, which made me think it was part of the casting!!! so THAT's getting ordered right now...

I thought the same thing on mine until I gave it a closer look. The black line is where the crack is. About 3/4 of the way around. Mine is above water so a little less urgent to make the repair. I have the SS attwood replacement, just haven't put it high enough on my mod list to get to.

 

[DoubleThrust]

I replaced mine for peace of mind. Didn't turn out to be cracked, but I feel much better anyway. Did the drain plug in SS too. Hell, look how I drive!

 

[Speedling]

Yeah, I did a hard turn like that this past weekend. Kids slid over too far and hit each other's heads. I got the STARE. guess that's not happening unless i'm alone on the boat... oh well.

 

[itsdgm]

So, I double checked the basic things quick while waiting for the wife to get ready to go to the mother's day party...
I believe my scupper is cracked, in almost a perfect circle on the inside, which made me think it was part of the casting!!! so THAT's getting ordered right now...

Did you go with a stainless one? They'll last much longer than another plastic one.

 

[jetboater4life]

Can the stainless plug be completely removed? With the plastic one I have I can pinch the part and remove the plug completely. Allows me to stick a magnet in there and grab stuff that may have been dropped in, or just to clean out any gunk.

 

[octavio3311]

I get water in on watersports days with the ballast tanks full regularly. I attribute this to the stern sitting low and water coming up over the lower deck. It's not a lot, but enough for the bilge to kick it out once in a while. On regular days - sometimes she's bone dry while other times she may collect a gallon or 2. I traced it down to water coming in thru the anchor drain up in the bow. With all the kiddies hanging in the bow, going slow thru chop (not on plane), water seems to come right in thru that drain.

 

[Speedling]

Yup, ss attwood
wife says it came today.
No time for it tonight because I have someone looking at the house tomorrow night.

 

[Speedling]

So, good day of testing. Not a single drop of water, even with a bunch of wakeboarding going on all day.
But, once again, when we put the boat on the trailer, and are cranking it up etc., it turns on like crazy!!!
I can only think that it's coming in from the whole back seam between bottom and top hulls. I guess I will try to caulk the whole thing in the back. Sheesh. I thought I had it solved all day. It's just that loading up!

 

[Murf'n'surf]

It's possible that the water sits forward in the hull and runs to the back when pull up on an angle. But it should run to the back when you throttle up. Strange!

Stick your head in there next time.

You gave a factory trailer?

 

[Speedling]

Yup factory trailer. Back of boat just sits at that water line when we are loading. As soon as we are at that point where it's hard to crank that last 6 inches, the back seam is at water line and with the engines running it bubbles up a bit. This is when the bilge immediately turns on and pretty much stays on until we pull up out of the dock. Then pull the plug and let it drain the way home which is a 3 minute drive
Then when I jack it up to take off the truck even more comes out! I installed a drain in my garage just for the boat draining like this.

 

[Julian]

Yup factory trailer. Back of boat just sits at that water line when we are loading. As soon as we are at that point where it's hard to crank that last 6 inches, the back seam is at water line and with the engines running it bubbles up a bit. This is when the bilge immediately turns on and pretty much stays on until we pull up out of the dock. Then pull the plug and let it drain the way home which is a 3 minute drive
Then when I jack it up to take off the truck even more comes out! I installed a drain in my garage just for the boat draining like this.

Is the rub rail in the water? If so...that is almost certainly your issue....leaking through the rub rail. You must have a steep ramp.

 

[Gym]

I don't want to start a debate here but do you keep your compartment plugs in while in the water? If you don't, like me, you may want to install them just to try to isolate where the water is coming from.

 

[Eric Popper]

My boat does the same thing. Every couple of hours when I turn on the bilge, it pumps for 10-15 seconds. Here are my observations:

1) My boat only seems to get water underway. This includes stopping so it could be from the back flow across the swim deck. This seems to be the likely culprit.
2) I removed the hatch around the clean-out ports last season to install the SS scupper and it is still just "sitting" in position with no screws or sealant. This could be part of the issue as this would allow water in that compartment to travel into the bilge. The same amount of water was still getting in the boat last season though before I opened this hatch though.
3) My boat usually doesn't sit on the water all night. On the rare occasion that it does, there is little to no new water in the bilge.
4) The bilge can only "get" the water while I am underway as it runs to the stern. There is not enough water to pump while sitting still or level.
5) One of my clean-out plugs has water on top of it sometimes. This could be the water on the plug but it is not consistent and the water in the bilge is consistent.

Regardless, I have never gotten enough water to be alarmed. I normally leave the bilge off and cycle it on a few times during a day of boating. This allows me to be able to observe the results of what does or doesn't come out. I have read all of the debates on whether to leave it on or off while on the water overnight and chose not to. We do an in-and-out service at the marina. The boat only stays on the water when we get back late, after the marina is closed. They put it away first thing the next morning. If I left the bilge on, the battery would certainly be dead from cycling on and off while on the trailer over the next few days.

We had a great day out yesterday. The water on the Chain of Lakes is still chilly for watersports, but the weather has turned great for boating. Here is my GoPro shot from sunset yesterday. I suctioned the camera to the windshield for this picture. I have ordered the roll-bar mount to attach it to the tower in the future.

E

 

[Murf'n'surf]

To everyone on the fence about where to keep your bilge switch: If your boat is in the water the bilge switch should be on. If you were to have some sort of failure while on the water you wouldn't know until your engines died from water ingestion. That's too late! Please keep that switch on and install a high water alarm to warn you of potential danger as early as possible. A 20-24 foot boat will be overcome by water very quickly.

@Speedling sounds like its time to investigate that rear rubrail. Luckily it joins the two sections at the rear and should be easy to remove the rail,seal the joint and reassemble.