99 Air with leaking muffler

[Ultimanta]

The fiberglass muffler on my 99 Air (aged about 480 hours) sprang a healthy leak at the end of the 05 boating season. Thinking I would save some big bucks ($500++), I patched the muffler last winter with a fiberglass repair kit. The patched muffler got me half way through this season with no problems, but then the tell tale signs of warm bilgewater appeared; this told me my patch had not lasted. I temporarily patched with Ge Marine Grade RTV Silicone Sealant and finished out the season with a dry bilge. Am I destined to purchase another muffler ($$ ouch)? What caused the muffler to fail in the first place? Its fiberglass, it can't rust or corrode. Is this heat damage?

Marty

[surroundsound64]

RE: 99 Air with leaking muffler

I'm betting you're going to have to replace it. Both of mine finally started leaking this year too. I was lucky in that I don't have the big exhaust unit that all of the new stuff has, I just have 2 fiberglass glass pack like mufflers. They are over $200 each, but I was able to replace them with #80 PVC pipe...
I don't really know what may have caused your leaky muffler. Mine had a little over 600hrs on them, but they each only handle 4 cylinders. You have one that handles 8 cylinders, perhaps your muffler just got worn out.

I'm sure someone else here knows more about it than I do though. Just my thoughts.

[Andrew]

RE: 99 Air with leaking muffler

best solution is to cut out the damaged area and rebuild it. ur patch is just that a "patch". the problem is that the patch is not a thick as the rest of the muffler and with it being on top, it does not have enough structural support to keep it from seperating from the muffler.

[wakejunky]

RE: 99 Air with leaking muffler

I would venture to guess that it started to leak from vibrating against the bilge or from the floor board. I don't know what's inside those but, structurally they're just fiberglass. Go to your local home improvement store, pick up some resin and fiberglass and repair it. Shouldn't be that big a deal and certainly much cheaper.

Chris

[NigelC]

RE: 99 Air with leaking muffler

Check out my post relating to an engine backfire and associated muffler damage:

http://www.planetnautique.com/index....amp;highlight=

Where was the damage on your muffler? Also, are the foam pads in place between the muffler and the hull? Without these in place, the muffler will wear through, probably at the bottom corners where the exhaust inlets are.

Nigel

[Ultimanta]

99 Air with leaking muffler

Thanks to all for your replies, perspectives and ideas.
My leak actually started with a small area on the left side of curved body mid way back where there is absolutely no contact with the bilge.

When I patched mine, I cleaned the entire patch surface with MEK. I applied two layers of 4 inch square patch on the leaky area. I then appled an overall patch on top of all by wrapping the entire muffler body to hold the patch in place. I will try to get a picture posted FYI.

The location of my leak is on the left side of the 'long' vicinity of the picture of the 'exploded' muffler posted. Wow! Mine is not that dramatic. Not even really a hole, per se, just a one inch square area where the fiberglass has flaked and began leaking. By the way, my leak and the 'exploded' picture posted are right on the internal baffle. Hmmm... I remember once when trying to restart a hot engine, that it failed to fire immediately. I kept cranking it about 10 second intervals. Did this twice and it started on the third try. Never heard a pop or boom. Don't know what caused failure to start. Never had starting problem with a cold engine.

Sponge rubber on bottom is intact but not as soft as it should be, probably will replace it.

[boatech]

RE: 99 Air with leaking muffler

the mufflers go bad all the time it will start as one little pin hole. yeah u can patch it or fix it but another will pop up soon enough . just bite the bullet and buy a new one. replaced one 2day on a sport naut. 88 or 89 has 540hrs on it. this guy would use 5200 and a screw in the pin hole. had about ten screws in it.