Broken Exhaust Shutter-Does it Matter?

[Woody from CamlachieOn]

Engine is 1995 4.3L Mercruiser Alpha 1 IB/OB, mounted in a 20 ft. Regal Boat<br />While doing end of season servicing, including checking my water pump impeller, the service shop found an "extra" brass part laying on the impeller.<br />The shop found it to be a broken "exhaust water shutter," Mercruiser Part # 99370A-2. There are two of them, acting as check valves on each exhaust manifold. One must be OK. My understanding is that they prevent water from rushing back into the manifold, due to large back swells, or if you let the boat "crash" into the water off of the trailer.<br />To fix requires the engine to be removed, as there is just no room, no how, for a body or arm to get between the transom and the engine.<br />Question: Running without the shutter, and knowing how to avoid the problem, seems better than yanking out the motor. I have two years experience on the lower Great Lakes. Don't want my limited "experience" to get me into trouble. I'm open to advice. Thanks...

 

[Trent]

Re: Broken Exhaust Shutter-Does it Matter?

You know the answer. Sorry Replace it or be sorry.<br />Removeing the engine is not that bad if you have a lift. Or you will be sorry.

 

[outboardguy]

Re: Broken Exhaust Shutter-Does it Matter?

To answer your question read this<br /><br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=24;t=005224 <br /><br />The exhaust flappers aren't really that hard to change,all you need to do is remove the exhaust the exhaust tube(#3 in picture)then remove and reinstall new ones.<br /><br /> http://www.mercruiserparts.biz/partsimages/CRUISER/801874.93/41.gif <br /><br />If the other side is broken like the first side,it could be punching a hole right now.Generally if it's broke and down in the y-pipe you can pull the drive and see it through the exhaust bellos hole,then get long tool and pull it out. Your'e lucky that one actually made it out of the pipe to the drive.

 

[f_inscreenname]

Re: Broken Exhaust Shutter-Does it Matter?

You cant miss every wave and all it takes is one in the right direction and you have water in your motor. you then have to pull the motor anyway. Oh.... that right first you will be stranded when it happens and you will also have to buy about a thousand dollars worth of parts. Think about it. Are you lucky enough to miss every wave???

 

[rkikenda]

Re: Broken Exhaust Shutter-Does it Matter?

I have a 2004 Mercruiser 3.0L 4Cyl that I just replaced the shutter on. I'm not sure if it is similar to yours, but it was an easy job. I didn't need to pull the motor for that, but I did for other problems. Even pulling the motor is not that hard. Check out Mercruiser Parts They give many diagrams of motors and drives.

 

[dmorley]

Re: Broken Exhaust Shutter-Does it Matter?

Unless your engine is really badly located, the flappers should be easy to get at as they are right on top of the Y's in the Y-pipe. Just remove the hose clamp that attaches the rubber exhaust hose to the top of the Y-pipe. But replace, I've seen what kind of damage occurs when just a little water hits hot valves.

 

[DHPMARINE]

Re: Broken Exhaust Shutter-Does it Matter?

Woody,you have brought up a good subject...How accessable is your engine.Through the years I've seen some really bad setups.Almost impossible oil filters,starters,even drain plugs.Sad thing is few people see this when looking to buy a boat.Then they pay later on the labor side.<br /><br /> Here in MA,we only play on small ponds(mostly) and the shutter issue is moot.I have seen 1 engine ingest water thru the exhaust in 25 years.<br />BUT it sounds like you are playing on big water.If the weather kicks in,and you're way out there,think about how long you can tread water in those waves.<br /> DHP

 

[Woody from CamlachieOn]

Re: Broken Exhaust Shutter-Does it Matter?

Thanks to all who responded for the advice. Repair it will be. (Woody)

 

[chris in va]

Re: Broken Exhaust Shutter-Does it Matter?

At least you found out in time. I didn't even know they existed last year until we stopped in the middle of a river on July 4th. All the boats racing upstream to watch the fireworks created some decent swells, and my motor hydrolocked. <br /><br />Seems the flappers had disintegrated previously. I ended up having to replace the flywheel because the guy trying to help me on the water attempted to start the thing several times. Grr.