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Shouldn’t rain water drain out the scupper valve?

jlcj7

Jetboaters Captain
Messages
731
Reaction score
695
Points
232
Location
Tega Cay, SC
Boat Make
Yamaha
Year
2011
Boat Model
SX
Boat Length
21
Went to a restaurant on the water and while there a brief but strong storm rolled through. When I left I noticed the boat sitting low in the water. Had some water in engine bay (but not up to the bottom of the engine) but both in floor storage compartments were completely full. (This pic is after some drained out when I started moving).
5C7B6280-F0B5-4988-9A8B-D1DF6CD4F0A6.jpeg

The compartments were closed during the rain.

Am I wrong that these shouldn’t fill with water like this while raining?

Also another weird thing. My bilge pump didn’t kick in to drain any of the water in engine compartment until I put the boat back on the lift. Then I kicked on and ran for 5 minutes.
 
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Picture right before rain
473F531D-395B-42CE-AB2B-F4BC1E6C8069.jpeg

And during.

7C912AAF-9351-4536-85E1-89F5F1091F78.jpegAA636EB0-ECC6-4D32-9CF1-31F87EBD99D5.jpeg
 
Had a similar issue with our boat. The switch had tripped the bit so the pump didn't come on and pump out the gazillion gallons of rain water that had accumulated during the Louisiana Typhoon season. Notified the sales agent and he grabbed a mechanic who climbed up under the helm and started giggling things around. Switch finally engaged and the pump pumped the water out but I feel your pain there. Didn't like seeing the boat after a couple days of rain completely full of water that's just standing. Just out of curiosity, does your boat have drain plugs at the bottom rear of those compartments? Ours does and they had all of them closed so the water couldn't move to the rear of the boat. I'm actually somewhat glad they didn't because that entire ski locker full of water draining into the eng compartment when the sump pump wasn't coming on could have spelled out disaster.

I had found this link as well but its mainly discussing replacing the scupper. Hopefully theres nothing broken on yours thats allowing water to come in as opposed to letting water out.
Yamaha Jet Boaters • View topic - One more on scuppers - SX210 replacement
 
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Should never have standing water. You have a problem with your bilge pump.
 
Thanks. I’ll have to check the scupper but on my boat it sits above the water line. And when I started moving all standing water in the bait did drain out so not completely sure it is related to that. I do keep all drain plugs in when on the water. Not a fan of letting all that water drain back into engine compartment.
 
I agree bilge should pump water out. But should the in floor storage fill like that during rain?

I had plugs in so I know it won’t drain out but just surprising to see those seals are not at least a little water resistant.
 
I agree bilge should pump water out. But should the in floor storage fill like that during rain?

I had plugs in so I know it won’t drain out but just surprising to see those seals are not at least a little water resistant.
Even with the plugs in on those lockers, water will come in from the hull. When my scupper valve broke, they filled up with the plugs still in. The way the covers for those lockers are designed, you shouldn't be getting that much rain water in them. You really need to check your scupper valve.
 
the seals are not as good as you think they are. I was caught in pretty nasty storm ( 60mph winds) for about 30 minutes and I ended up with about 4 inches of water in the ski locker. High water alert went off too.

I keep my drain plugs off all the time and eventually the bilge pump took the water out. Although when I got home there was some left ( maybe 3 or 4 gallons).
 
that's a lot of water from one brief down pour, If it was a day full of rain I could understand,

If you compartment plugs are in then it should only be water draining from your floor/around your hatches getting in there, although in older models those compartments aren't sealed and if you look up from down inside you can see openings to the hull, water could drain through your cup holders down the inner storage to those compartments ???

either way I'd want to try to get a better idea what went on and figure out, do you want to go compartment plugs in or out and do you want to add a secondary bilge as back up (maybe even a high water alarm),


.
 
and to your original question, it should drain underway because of gravity, but as zipper had posted when he wet slips he has to add a ballast bag to the swim deck to change the pitch as the boat naturally sits more nose down in the water,


.
 
You can see in the first pic that the hatch seals aren’t making contact with the hatch (particularly around the hinges).
 
Much of the rain will go out the scupper as long as your boat is weighted stern down. The internal drain plugs will slow water movement down but they arent "sealed".

I'm pretty sure you have a leak somewhere. You said you thought it was sitting low....I'll bet you have a drain, though hull fitting or anchor lock drain leak....or multiple.
 
Ok. Lots of investigating to do. I can boat all day (when not raining) and not have a drop of water anywhere, nothing comes out rear drain plug, etc. when the cover is on, obviously no rain enters as well.

Maybe I’ll take a hose and spray the inside floor down continuously and see how much water enters those lockers.
 
Idk where it comes from but my boat sat on trailer for week having hubs serviced before last trip... it poured and poured... whole ski locker was filled almost. I had to take care compressor and blow air through that drain plug. It then proceeded to drain. Could have something clogged, or if you had the plug in from locker.
 
and to your original question, it should drain underway because of gravity, but as zipper had posted when he wet slips he has to add a ballast bag to the swim deck to change the pitch as the boat naturally sits more nose down in the water,


.
Mine fill like that when I get heavy rain. Rainwater is not going to flow out the scupper (or bilge via pump) unless the boat is weighted stern down. Those hatches are the lowest point in the boat when its sitting on the water (or trailer for that matter). With the plugs in...they're gonna fill up. My pump works fine and I don't have any leaks. I pull the drain plugs in those lockers and get the boat moving before getting on plane...bow up. The water drains into the bilge and gets pumped out. Then I replace the plugs. If you leave the plugs out of those lockers while on the water, the rainwater still won't pump out until you get her bow up. It's the lowest point of the hull. There are a few threads about this.
 
The locker seals suck. If you follow the plugs in rule when on the water they will fill up and there is nothing you can do about it until you pull the plug and drain it to the bilge. We got a storm today and it filled the forward compartment to about a 6” depth. The cooler filled too but I was using it as a cooler full of water and ice already, so no idea how much more got in there. Also, on our hull, water in the bilge sits very far forward. It takes getting on plane to move enough aft and into the engine bay for the bilge to actually pump it out.

I pulled the forward locker plug after the storm but never saw water get pumped out once we started running again. I pull the boat out tomorrow and will see how much comes out.

I am curious how many gallons it takes when the boat is sitting static in the water before it actually trips the stock bilge pump. I bet it is 20 gallons plus.
 
Is there enough of a trough around the hatch opening to add gutter drains plumbed directly to the bilge?

 
My drains in the ski locker and fuel pump hatch were clogged. I sprayed them all out with a hose as well as flushing out the hull while parked uphill.
 
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