Exhaust baffles... need your opinion

[christians89]

To start off the boat im working on is a 1990 sunbird with a 4.3 omc cobra stern drive. Recently the exhaust baffles have melted due to a lack of water, bad water impeller. I was going to fix it but after doing some research the Volvo 4.3's used baffles up to 1999 and after that model year they stopped using them. Apparently they were more trouble than good. That's just what I found.. In my opinion, as long as the engine is running there should be no way water is going to go back up into the exhaust and into the engine. I can see if the engine stalls while coming off plain water could rush back into the engine. Just looking to see what everyone thinks. The engine on my boat runs great, never had any stalling problems whatsoever. If it were to stall I wouldn't have a problem pulling the plugs to empty the cylinders.

 

[donberry]

Re: Exhaust baffles... need your opinion

curious what the replies will be. When I pulled the engine on mine, a 1988 4.3l, it did not have the baffles in it. I googled around and decided to just do without them. Interesting to see if I made an ok decision

 

[Joshua Nichols]

Re: Exhaust baffles... need your opinion

HMMMM I found that someone removed my flappers too.... When I installed my new exhaust.. I went ahead and installed some new ones.. I never had a hydro-lock without them on my wing-type manifolds..

With my new center riser type exhaust seemed maybe lower. I went ahead and installed new ones.. They didn't cost much..

I also didn't care for the idea of pulling spark plugs out in the middle of the lake.. Working on a boat in the water, isn't like working in your driveway..

 

[Lou C]

Re: Exhaust baffles... need your opinion

Mine still has the originals, and I checked them to make sure they move freely, they were fine salt water use and all. I'd replace em, I personally disagree with Volvo, in that there are operating conditions that can force water up the Y pipe (fast stop, someone cuts you off, tuber falls off tube, etc). Plus some boat installations put the engine and exhaust lower than is optimal.

 

[joemamma]

Re: Exhaust baffles... need your opinion

I agree with Lou C
Especially if to trailer, Slide that thing backwards off a trailer without the engine running. If you slide it down with it running you'll tear up the impeller before it hits the water.
There a little cheap insurance. Do whatever you can to keep the water out of the engine. I've said it before "Its a screwed up system".

 

[christians89]

Re: Exhaust baffles... need your opinion

Thanks for the reply's guys. A marine mechanic I had talked to had told me I would have to remove the engine just to replace them so that's what made just consider not replacing them if there are a lot of boats that never had them to begin with. Keep the comments coming!

 

[donberry]

Re: Exhaust baffles... need your opinion

don't see why you would have to pull the engine. Just need to take off the exhaust hose. On mine, I did find it easier to just go ahead and take off the manifold as I replaced the exhaust hose, which gave me a chance to put new gaskets on it anyway

 

[christians89]

Re: Exhaust baffles... need your opinion

I believe I may have called them the wrong name. What I mean is the flapper?? Same differance. Anyways where are yall finding them for sale. After a quick search on the web I cannot find them anywhere. Also does anyone good pictures or technical diagrams of them? Thanks everyone for sharing their experiences, I guess I should go ahead and replace them just to be on the safe side of things.

 

[Randy J]

Re: Exhaust baffles... need your opinion

OMC i have 4.3 and got new last year from local OMC dealer, Volvo different part number as i called a volvo dealer also but sincea i didnt know if different design and didnt want to drive 80 miles just to see the volvo as they were in stock i just had my local OMC order for me.. so check dealer

 

[christians89]

Re: Exhaust baffles... need your opinion

I have to heck with them. Thanks again everyone!

 

[wiz156]

From what understand, to put this at rest, flappers do two major things. First, they create back pressure to keep your engine as it is designed to run. Second, especially when launching your boat, they prevent that surge of water from washing through the exhaust into your manifold. If this happens, any exhaust valve that may be in the open position will allow water into the cylinder. Keep the flappers installed.