Exhaust shutters, yes or no.

[Baylinerchuck]

Just curious as to the opinions on exhaust shutters. I have a 1990 Mercruiser 4.3L LX that has the original single flap type shutters. I pulled the exhaust apart due to some troubleshooting I'm doing to diagnose a lack of power and RPM at WOT. The pins that hold the shutters in the Y pipe are slightly worn, however the shutters look fine overall. Just curious of the opinions of those on this forum on whether or not you would reinstall these oem shutters, install new style shutters, or leave them out altogether. Thanks.

 

[Oshkosh1]

I don't get it...WHY would you NOT re-install them if they're fine??? That's what the engineers designed for it...leave them alone. As far as the "shutter" or "no shutter" debate? Yeah right. Again...Mercury Marine paid a LOT of engineers with a LOT of PhD's a LOT of money to determine if they should go to the trouble of installing them. A few people who have anecdotal experience THINK they know better. A friend of mine IS one of those engineers. We talked about those things years ago. He laughed when he heard of people leaving them out. "Oh...our dealers love them"...

 

[fishrdan]

Yes....

 

[Baylinerchuck]

I have seen a few opinions on here stating they left them out, but I totally get the anecdotal experience statement, and I agree with leaving them in. Just wondered if there was overwhelming experience to the contrary. Also since I have the original single door shutters that are obsolete should I change them to the new double door shutter that merc currently specs. Is there a good reason to do so? Thanks for your replies!!!

 

[Scott Danforth]

on a merc, you need the exhaust shutters

 

[Bondo]

Ayuh,.... I consider shutters, Required,.....

 

[Baylinerchuck]

Yes indeed, that seems to be the consensus here. I ordered the new Quick Silver design since I have the older now discontinued design. I figure if Mercruiser updated these parts there's obviously a reason. Thanks for your input.

 

[achris]

Reason for the update was that the old 'single vane' shutters could (and often did) lodge in the bottom of the y-pipe when the pin wore through. Often they would vibrate and create a hole that allowed water in. Not a good look!

In the stickies is a document I wrote on Merc exhaust shutters. You might like to read it...

As for leaving them out? Not what I would recommend.

Chris......

 

[Baylinerchuck]

Thanks Chris, maybe it's because I'm on an iPhone and have no PC or I'm totally inept, but where are these stickys. I spent some time looking and using the search but I can't seem to locate. Quite honestly I'm not sure what a sticky even is. Sincerely I Boats supreme newb.

 

[stonyloam]

"Adults Only" at the top of the forum. "Mercruiser information" section.

 

[Baylinerchuck]

I got it. Thank you!!! Strange title for I/O information. Honestly thought there was questionable content. Maybe it's an I-boats right of passage. I'll be visiting that section often. Thanks again.

 

[Oshkosh1]

Something's wrong at "Boatinfo"; I tried to read one of the manuals and for the past two days the site has been down. Hopefully only a temporary issue. A very valuable resource for the DIY's who don't need to invest in manuals, just need to consult them occasionally.

 

[JASinIL2006]

I was on it yesterday and it worked for me then, but it's down right now.

 

[Bondo]

Strange title for I/O information.

Ayuh,.... That's because nobody will read the "Stickies", if ya title it I/O Info,....

So, DonS decided to call it the Adults Only section to see if anybody would read 'em, without bein' Told to go there,....

If the title bothers ya, click the Stickies Info just below it,....
It's the same page, different title,.....

 

[ethan169]

I hope this doesn't seem like thread hijacking but...I was just about to start a new thread on this and saw this one instead.

achris - I've read your post on the three different current exhaust shutters. I don't see inline engines mentioned anywhere. I am referring specifically to an 81 merc 165 L6. I have a single right angle exhaust tube with what looks like the dual wing shutters. They are worn and I'd like to replace them but I don't know with what. The parts catalog lists the old style was OEM. So which part number would fit in a single tube? The same one on the Y pipe for the V6?

From achris's post

So, in brief.
-807166A1... for new style (1996 and on) Y-pipe (except batwing V6s).
-807166A2... for batwing V6 manifolded engines. Or ones that have been converted, but still have the original Y-pipe.
-807166A3... replacement for all old style (1982-1995) shutters. Use this number when replacing them too.

Chris...

Actually now that I read it again it almost looks like all the older styles should use that last one 807166A3. However you give a year range of 82-95. What about older versions? Mine is from 1981? My assumption is to use the same one?

 

[achris]

My document is for V engines only. For in-lines, go by the Merc part number.

 

[ethan169]

Thanks Chris.

 

[Baylinerchuck]

Ayuh,.... That's because nobody will read the "Stickies", if ya title it I/O Info,....

So, DonS decided to call it the Adults Only section to see if anybody would read 'em, without bein' Told to go there,....

If the title bothers ya, click the Stickies Info just below it,....
It's the same page, different title,.....

Thanks Bondo, title doesn't bother me in the least, just glad I was pointed in that direction. I will be hitting that thread often. Thanks for the help.