Water shutter/ flapper question

[rubherchicken]

Ok 1987 s23, 5.7 alpha 1 "R" drive. Was wondering where the water flappers/shutters are located. Are they in the top part of the y pipe right after the elbows? or at the bottom of the y pipe. My boat has been overheating, so I am replacing the impeller in the drive and thermostat. Has some noise coming from the y pipe like a knocking sound so I think its a flapper issue, wondering if it melted one or both of them ? so I just wanted to know where they were and If a faulty flapper could have something to do with overheating and noise? noise only at low rpm's

thanks again

Tony

 

[NorCal Boater]

Flappers are at the top of the Y. Pretty easy fix.

 

[rubherchicken]

Flappers are at the top of the Y. Pretty easy fix.

thank you very much, I am guessing that I just need to remove the elbows ??? seems easier than having to remove y pipe....

 

[NorCal Boater]

It's been a while since I did that job but if I remember correctly the 5.7L has a rubber hose that goes from the elbo on the manifold to another elbow. That elbow has a rubber hose that goes to the Y pipe.

Usually all you have to do is loosen all the hose clamps, slide the hose that connects the lower elbow anf the Y pipe up the elbow and off the Y and just rotate the elbows up and out of the way. That should give you access to the flapper valve.

Take out the old ones, put in the new ones and put all the hoses back and tighten all the clamps. It should only take about 30 minutes a side. The hoses may be stuck on to the pipes but a radiator hose removal tool will help break them loose.

Have fun.

 

[rubherchicken]

Ok so I took off the elbows and found the flappers,,, one of the flappers has broken in half and is missing, I stuck my hand down t here and didnt feel anything, looked down both sides and used a flexable spring rod to feel around and try to dislodge any pieces.. I didnt feel anything. I took off the exhaust bellows at the drive and looked up into the y pipe from the back of the boat and didnt see anything. Checked in the prop and lower drive for pieces and cant find anything. Where the *ell did it go? I had the rattle clanking noise at low idle. could it just have been the broken flapper that was still attached to the pin making all of the noise? not sure what to do next.

 

[NorCal Boater]

What you heard at idle was the broken flapper. Without the rubber on them they are quite noisy.

After looking all the places you did for the pieces I would say your motor passed the parts....kinda like passing a kidney stone.

 

[charlieft]

It's been a while since I did that job but if I remember correctly the 5.7L has a rubber hose that goes from the elbo on the manifold to another elbow. That elbow has a rubber hose that goes to the Y pipe.

Usually all you have to do is loosen all the hose clamps, slide the hose that connects the lower elbow anf the Y pipe up the elbow and off the Y and just rotate the elbows up and out of the way. That should give you access to the flapper valve.

Take out the old ones, put in the new ones and put all the hoses back and tighten all the clamps. It should only take about 30 minutes a side. The hoses may be stuck on to the pipes but a radiator hose removal tool will help break them loose.

Have fun.

My boat just lost a flapper ... it got stuck and caused the exhaust bellows to pop off the drive.
My marina quoted me 8 hours labor to install a new flapper??? I have 350 magnum engines with B3 drives. Their estimate seems a long way from "30 minutes a side" ????

 

[NorCal Boater]

My boat just lost a flapper ... it got stuck and caused the exhaust bellows to pop off the drive.
My marina quoted me 8 hours labor to install a new flapper??? I have 350 magnum engines with B3 drives. Their estimate seems a long way from "30 minutes a side" ????

I have never done the job on a B3. Only small blocks and Alphas.

Do a Google search for Mercruiser Flapper Valve replacement and see what you get. I just did

http://www.justanswer.com/tags/boat...per valve replacement &JPAF=txt&JPCD=20091215

 

[berkan]

Hello!
I am going to replace my watershutters in my 270 da 1997 with a 7,4l and bravo3!
But the original shutters cant be found in Sweden, so i need to know if there is a replacement partnumber for this!

So if anyone knows what to put there instead of the original that is made of rubberized sheetmetal i woul appreciate it very much!:huh:

 

[Quint4]

Do not have the part number but they have went to a new design that push into the top of the y-pipe. Very easy to install. Here is a pic from my install last Spring.