Flapper valve

[Keithowsley]

I have a alpha 1 gen 1. On my mercruiser 470
And I replaced the gimbal bearing and bellows and water impeller pump and reassembled
I noticed some talk about a flapper valve
Is there one one my boat and if so where is it?
My first time working on an out drive.
seems to be working fine right now

 

[Bondo]

I have a alpha 1 gen 1. On my mercruiser 470
And I replaced the gimbal bearing and bellows and water impeller pump and reassembled
I noticed some talk about a flapper valve
Is there one one my boat and if so where is it?
My first time working on an out drive.
seems to be working fine right now

Ayuh,..... Welcome Aboard,...... It's in the top of the down-pipe, just after the exhaust riser/ elbow,.....

 

[GA_Boater]

The shutter/flapper is item #7 in the link below;

Exhaust Elbow Assembly - Mercury OEM Parts - iboats.com

Exhaust Elbow Assembly - Mercury OEM Parts - Since 1998, iboats is the most trusted water lifestyle online store for boat parts and accessories, boats for sale, and forums. Enjoy great priced products with fast shipping.

ww2.iboats.com

 

[Keithowsley]

Is there a way of knowing if it needs replaced. Or just visibly look at it ? Some post say it’s not even needed?

 

[Keithowsley]

It has a closed cooling system
So would that still have a flapper?

 

[Lou C]

Yes even with a closed system you have raw water coming the cooling system to cool the heat exchanger and that raw water has to exit. The flapper is there to keep water from backing up the exhaust into the cyls. The water level in your Y pipe might be as high as the top of it when the boat is in the water. If the flappers are burnt looking or rattle and make noise its time to replace them. If not as long as they move freely they are OK.

 

[Keithowsley]

Thank you. I’ll check it out.