Offshoreonly.com - 502 sucks water through air intake vents

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Quote:

Originally Posted by Knot 4 Me (Post 4647711)

The 252 did not have side vents and your air intakes from the rear of the sun pad look factory and unmodified to me. However, from your pictures I cannot tell if the engine compartment liner is still intact. Can you give a better pic showing the overall compartment and a pic of the entire underneath of the sun pad?

A few things stand out to me. One is your tailpipes or lack thereof. A second thing is the caulking around the transom plate. Might be another source of water in your bilge. A third is what appears to be a jigsaw cut in the transom wood on the starboard side.

These pics should help for reference:

https://www.powerboatlistings.com/view/48004

Rear sun pad area and air intakes:

https://www.powerboatlistings.com/view/38541
https://www.powerboatlistings.com/view/49203

I don't think the inside of the engine compartment is modified but I will take a picture.

The tailpipes: the boat had silent thunder which was removed. The pipes are the factory pipes, they stick out just a couple inches. Do I need extensions?

That picture is showing the opening under the sun pad. I think it was cut with a router and it looks like the router got too deep. It is exactly the same on the port side of the boat. I believe this cut was made by the factory, but I'm not 100% certain.

Quote:

Originally Posted by wmgreene (Post 4647764)

The exhaust would have exited flush with the edge of the swim platform when it had the silent thunder box on it. Exhaust tips should have been added after the removal of the box. The box would have had external rubber flappers to help with water being pushed back up into the box/exhaust. I cannot remember if there are internal flappers upstream of the box. If not, it is only a matter of time before you hydro-lock your engine. Without exhaust tips, the water in the exhaust is exiting the transom well under the swim platform. A set of tips would extend the exhaust further away and might have an affect on water being sucked in thru the air intake if that is indeed what is happening. You would then also have reversion protection with either an internal or external flapper depending on the tip you choose.

It definitely looks like someone has been cutting in the engine compartment.

How about shoving some open cell foam in there to see if it makes a difference? It sounds like you may end up cutting in some side vents?
https://cimg7.ibsrv.net/gimg/www.off...f4c3f52ecc.png

You need exhaust tips and Salesbury flappers.

It still looks to me like the engine compartment liner has been cut out some and someone started cutting on the transom because it has been leaking and wet (see caulk) and then gave up.. I hope I'm wrong. Better pics will help tell the story.

As stated above, I'd remove the factory tips that are there now that hooked up to the silent thunder box and put on proper exhaust tips that extend out further from the transom. Corsa, CP Performance, etc. can set you up.

Quote:

Originally Posted by wmgreene (Post 4647551)

https://cimg7.ibsrv.net/gimg/www.off...c121da6513.jpg

Transom.
https://cimg6.ibsrv.net/gimg/www.off...f0f2007ae0.jpg

Opening under sun pad.
https://cimg4.ibsrv.net/gimg/www.off...4bbcc03c5b.jpg

Opening under sun pad showing path to engine compartment.
https://cimg5.ibsrv.net/gimg/www.off...e46ec0f619.jpg

Inside engine compartment looking up directly below opening under sun pad.

You could also be getting water rushing back toward the boat when you stop and going over the swim platform entering the bilge that way.

Quote:

Originally Posted by ezstriper (Post 4647671)

as a boat is pretty flat in the rear its the old station wagon effect water mist being sucked in, only cure it to seal the area with some sort of rubber flap etc, some boar worse than others with this..I have been on bigger cruisers and you actually get wet sitting in rear area

Similar to with horizontal mounted vents, build a drained catch box to manage the water. Does your blower exhaust out of the back vent. That may help break up a vacuum situation.

https://cimg4.ibsrv.net/gimg/www.off...59b34c8818.jpg
I really don't think it is the design of the boat. Formula sold a lot of these 252's and if it was a design problem we'd see a ton about it on the ol' internets. I owned a boat with a similar air intake setup for 3 1/2 years and not once did I get water in the bilge from water being drawn in from behind (see photo. a little hard to see with cover on but you can see no side vents, air intake under back of hatch visible where cover cutout is where it snaps down in back).

Have you Go Pro'd the boat while running to film the water being drawn in?