Internal Flappers
 

I just purchased 4 of the Hardin-Marine slide in 4" flapper in cased in a stainless housing that slides over the inlet side of the exhaust tip or pipe before the transom.
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Upon start up on a garden hose it sounded like a rod knock. It then got quieter with water flow. It also seemed to quiet down the engine noise like a muffler. After boating for a few days the noise got a lot less. I looked up my exhaust pipe and noticed the bottom part of the flap was not resting against the ss housing like it was during installation , It seemed to bend out a bit. So now i'm wondering if i can trust this type of setup. Is it going to let water by or is it going to shut closed. I don't like these./.. So

After searching the net I found another type of internal flapper made by stainless marine. Has anyone used this type?. Do they make any noise especially knocking sounds. These are 3.5" long and they slip into the 4" exhaust hose


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Any suggestions here. I have very little room between my exhaust pipes and the transom.

Haven't used either type but Stainless makes some quality stuff IMO. The Hardin ones you have should still slow down the back rush of water a bunch because of the design. Nothing is 100 percent. Figure your using this type instead of the external rubber flapper because of the looks, but even the rubber ones will pass some.

The ones i have from hardin marine you can't see. The are inside the hose

Agree, I meant the type that clamp around the outside
http://www.starmarinedepot.com/smd/i...ice/ZZ7764.jpg

they are useless for me. I had a issue with water a month ago due to my setup.[ATTACH=CONFIG]544659[/ATTACH]

Notice the holes at the bottom. That's where the water comes out with the muffler in the closed position. So the external rubber flapper on the outside does nothing

I have the stainless marine on my boat.... the picture doesn't show the rubber tips mine have or had I should say... they didn't last long.. and neither did the internal flapper... at about 35hrs one of the flappers disappeared.... fell out! I then put the clamp on rubber flappers on....

You must have burned it off.. I just ordered the stainless marine ones. They look more positive shut off then the ones i have now

The rubber wears off it doesn't burn off with water exiting through them... once it wears off they make a racket at an idle.... but for one of them to just fall out? I won't be buying another set..

At least these will open not like the ones i have. The material bends from running at higher rpms but when you shut off the engine it doesn't retract, stays open a bit and I'm worried water will pass up there again. I'll have to inspect them when they arrive..Didn't you call customer service and tell them the rubber wears off and one fell out. Stainless marine makes some nice stuff..How can that happen?

I really didn't care that it fell out...I plan to take the other one out now that I added the external rubber Flappers... without the rubber tips they still work fine but do make a racket when idling....Under 40 hours & the rubber tips are pretty much shot... sounds like you can not use the rubber Flaps so these will work for you I'm sure.... better than nothing anyway right?

edit... now that I look at what you've purchased it is not what I have... my internal flaps are built into the tip.... not an add on...

I also found these with look a lot better. They are made by Corsa Performance and they have a weight that keeps them shut when the engine is not running

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Haven't seen those before those are pretty neat. They still look like they have the potential of making even more noise if the rubber vanishes. Sure would be nice if someone came up with something instead of the rubber that would last longer...I was going to do the Hardin ones that you bought when I found my internal ones were missing. I ended up buying the OE style ones from Teague instead they were only $25 ea.

Think if you just had straight tips you could use the external flappers. The Corsa muffler tips I removed didn't have the holes on the under side and the flappers are pretty much in good shape as when installed. Understand you have more power, but maybe just straight tip change would be the easiest

[IMG]http://i609.photobucket.com/albums/t...ps3f473e8d.jpg[/IMG]

I was considering removing the HP Gil select sounds mufflers and just putting a 4" straight pipe with a outside flapper but I do like the ability of flipping a switch and the low end bark engine sound disappears. I just bought them a few months ago brand new ..I would hate just to have them sit around. They were not cheap

I hear ya I really like my silent choice it's a must for what we do... so far anyways lol. Assuming you can't run the internal flappers I'd say the Hardin ones you bought might be your best bet. I ran across these as well during a similar flapper thread I created: http://www.offshoreonly.com/forums/d...ce-please.html