Another Mercruiser exhaust flapper question.

[Boomyal]

Merc 888/898 R series/pre-alpha? drives. What happens if you just leave the exhaust flappers out? My '75 OMC never had them. I do realize they may have been significantly different designs but I had to ask.

 

[zshooter]

Re: Another Black anchor exhaust flapper question.

Re: Another Black anchor exhaust flapper question.

When I went to a Mercruiser tech to get a replacement flapper, his response was "hell, we just throw those things away."

The purpose is to keep water from rushing the wrong direction up the pipes. Quick stops after running high speeds, big waves when stationary, or running at speed in reverse are the most likely causes.

I paid the $15 or so for the part and replaced mine. But apparently there are lots of boats in Arizona running without them. Good luck.

 

[Boomyal]

Re: Another Black anchor exhaust flapper question.

Re: Another Black anchor exhaust flapper question.

^Bump. I kinda like the last opinion but are there any more?

Also, how many bolts hold the down tube to the Y pipe. It's kinda hard to see back in there. Looks like you have to remove the risor elbow from the manifold and the stepped rubber coupler before you can remove the 4" down tube from the Y pipe?

 

[northvanwatertaxi]

Re: Another Mercruiser exhaust flapper question.

there are 5 bolts holding the bottom of the y and leaks in that area can be common
engine removal is nessesary and so is inspection of the drive hub, better change that if it is worn
also the water in the y pipe can freeze during cold weather