re water flappers

big ken

Petty Officer 1st Class
Joined
Jul 19, 2008
Messages
200
hi iseemed to have lost my previous post. i have a 1978 165hp inline six ser#4608326 would the water flapper happen to be in the exhaust pipe on the transom? i have a 4in oblong exhaust pipe on tranom side with a riveted bar in the center and was wondering if that used to be a water flapper that caroded away and if so do i really need it? thanks ken ps it is a mr1 outdrive
 

fishrdan

Admiral
Joined
Jan 25, 2008
Messages
6,989
Re: re water flappers

The metal bar going across the center of the exhaust pipe is the remnants of your old exhaust shutter. The shutters are in there to prevent the exhaust manifold and engine from flooding in the event you take a wave across the stern or abruptly stop the boat,,, which will swamp the exhaust. Soooo, yes it needs to be replaced.

If the old one is riveted in there you will need to drill out the rivets and then screw/nut the new one back on. Don't loose the brackets that hold the shutter as you will reuse them when installing the new shutters. I would also lock-tite the nuts to make sure they don't come loose.

Now you have to ask yourself what caused the shutters to burn out, lack of water flow, running the engine without water, old age?
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
18,185
Re: re water flappers

Also ask yourself where did they go!!!If they are in the exhaust they can cause a blockage and overheat.Usually they melt into small pieces but look for them.Jerry
 

big ken

Petty Officer 1st Class
Joined
Jul 19, 2008
Messages
200
Re: re water flappers

thanks guys. thats what i was afraid of. wish i would have caught it before installing motor, would have been easier. as far as why. it is probably 30 years of chesapeake bay brackish water. i also was concerned where it went to. the outdrive is off and being inspected and while it is off i run a water hosein where shutter was and caught the water coming out of the transom and it was clean. its probably been gone for some time..
 
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