MUFFLER

[grania]

Hello all-hope youve enjoyed the great sailing summer we've had. Im looking for tips on replacing my Volvo Penta MD7A muffler, on my '79 CD 9M Intrepid. Not sure if the present one is the original, but it sure looks old enough. Volvo no longer makes the replacement. Has anyone had luck with a suitable replacement? Its been suggested that there is an epoxy I can patch the present muffler with, but its too thin and beat up to weld, Im told. Any advise? Thanks, Aine

[Russell]

You could try Marine-Tex (the grey version, not the white), for a temporary fix. Its pretty great stuff, but it wouldnt be consider a permanent solution.

[sgbernd]

I used JB weld to fix the pinholes at the weld. First I sanded all the rust, peeling paint, and corrosion as best I could from the affected area, the cleaned with acetone to remove any oil or paint residue.
Then I used the JP weld and let it cure for a few days. Part of it later burnt off when the inlet water got partially clogged creating a horrible smell, but it is still holding.

It is not a permanent fix as it is not structural, but it does seem to have stopped the pinholes from seeping and that was 2 years ago.

[mgphl52]

I replaced the custom stainless steel muffler with a Yanmar mixing elbow, some black iron pipe fittings and a small fiberglass muffler. Works great, makes it a bit easier to get to the water pump and it has a much higher lift from the exhaust manifold. If anyone is interested, I'll try to get some photos.

[sgbernd]

Michael,

did you have a custom adaptor made to fit the Yanmar mixing elbow to the MD7 exhaust manifold? Or did you just cut the far end off the old one and weld an adaptor to it? This seems the tricky part for me as the rest can be made up with off-the-shelf products. I am interested to hear your solution as I plan to tackle it this winter.

Steve

[Michael Abramson]

Hi Aine,

I have the same exact setup in my boat. I use the smallest Vetus plastic water lift muffler. Here is a link to their catalog, find Mufflers
and you can see a drawing.

http://www.vetus.nl/digcat/DIGCAT_2007_ ... digcat.php

I can not say if the one shown in the upper left is exactly the same as mine, which has been in my boat for the 8 years I have owned it. The drawing looks a bit different. But they must offer something close to what you will need.

I think I have an aftermarket mixing elbow that screws into a flange on the rear of the exhaust manifold. I don't know who makes that, there is no marking. Perhaps you won't even need that, but I don't know what you can reuse from the original Volvo
installation.

The only drawback to my setup is that it is right in the way when I open the panel from the starboard locker. An ideal installation would move the muffler to the port bulkhead alongside the engine bay, and then access to the engine would be improved. It would mean some longer runs of expensive exhaust hose, that is the only reason I have not done it.

Let me know if you have more questions.

Michael

[mgphl52]

We used the original plate that bolts to the exhaust manifold and, if I remember correctly, had to add a coupling to match the size of the nifty left-and-right hand threads of the Yanmar coupling. The elbow was about 170 degrees and with a short piece of hose, the plastic muffler sits very nicely on the stainless bracket that we salvaged from the original Cape Dory muffler. Sorry I haven't gotten the picture yet, but maybe this weekend... Our marina is also a stop for large "poker run" tomorrow so I'm sure I'll have a camera with me!

[miguel mascaros]

The name of the product that worked so well on the pin-holes is
OATEY EPOXY PUTTY
prod. No. 31270
part No. 07016
phone contact...216 267-7100