Exhaust Flaps Needed?

[trailshredder]

I have acquired a boat that has thru the hull exhaust (Captains Call). I had some water leaking in around the exhaust flanges so I pulled them this weekend and re-sealed them with 5200. They had the rubber exhaust flaps on them but there are also metal flaps in the extensions. My question is; are the rubber flaps even required since there are flaps inside the pipes?

 

[81 Checkmate]

Do you have the switchable exhaust? If so i would still want the flappers in the Y-pipe.

 

[alldodge]

I have acquired a boat that has thru the hull exhaust (Captains Call). I had some water leaking in around the exhaust flanges so I pulled them this weekend and re-sealed them with 5200. They had the rubber exhaust flaps on them but there are also metal flaps in the extensions. My question is; are the rubber flaps even required since there are flaps inside the pipes?

I would suggest yes, and the reason behind it is to keep water from getting to your exhaust valves. When you stop water comes rushing up and the rubber flaps help stop it from coming in. If you slowed down slowly they wouldn't be needed, but Murphy is always just around the corner. So they are very cheap insurance and cost way less then an engine.

 

[trailshredder]

No Title

But there are flaps in the extensions and the black rubber flaps. Do I need both? Flaps inside extensions look like this ....

 

[81 Checkmate]

So i take it you dont have switchable exhaust..........Me personaly i would keep them both! Why take a chance of hydo - locking a motor

 

[trailshredder]

Yes, sorry, it is switchable exhaust.

 

[achris]

If they are switchable, you DEFINITELY need shutters in both systems.

 

[81 Checkmate]

Where do your tips exit the boat.......at the water line or way above the water line?

You see boats all the time with no flappers outside the boat on the tips..it's becouse they have internal flappers like the picture you posted....which is ok, but still taking a chance if you have to back down and the water rushes the back of the boat...which in turn could be sucked in the motor and cause a hydro lock. Id leave it the way it is....preventive thinking. I would also check to be sure you have flappers inside the Y-Pipe as achris said.