Water Shutter / Flapper Valve?

[Simoniz]

Alpha 1 Gen 2 merc 3,0 litre engine.

On pulling the exhaust apart I discovered half the flapper valve was missing.

Is it worth replacing this part? I heard that Mercruiser themselves had ceased fitting it in new boats.

 

[Bondo]

Re: Water Shutter / Flapper Valve?

Ayuh,... Mercruiser is still using them,.. Volvo dropped them on some models...

Yes, Replace it...

 

[cruisewave]

Re: Water Shutter / Flapper Valve?

Well....It actually all depends on how your boat sits in the water. Most of the time those flappers were used as a back up to prevent water going back into your engine through the exhaust. my expierence in most cases is that those flaps are usually useless. Unless you overheated your engine real bad your flapper has probably been broke for quite some time now....So if there is no water in your oil then i wouldn't worry about replacing it.

 

[Don S]

Re: Water Shutter / Flapper Valve?

So if there is no water in your oil then i wouldn't worry about replacing it.

Flappers will not keep water out of the oil, only out of the cylinders. If the water leaks past the rings into the oil, then the rings were dead to start with.


Replace the flappers, they are designed to keep big waves and surges from getting a LOT of water into the engine. Especially those water sports guys that like to go fast, stop and shut the engine off immediatly to pick up a fallen skier or boarder. That wave can push water right up the exhaust tube and into the engine.

 

[cr2k]

Re: Water Shutter / Flapper Valve?

Make sure you get the old one or parts out especially the pin. I have replaced Y pipes cuz the pin rattled around and wore a hole in the bottom of the Y pipe.