1979 Johnson 9.9 noise

[rolmops]

My 9.9 is very loud ,although, apart from that it runs fine. I am trying to make it less noisy and one of the things that may help is installing a rubber seal between the upper and the lower exhaust housing. It is lacking on my engine. The part number is 0318996. I have been hunting for it all over the place with zero succes. Does anybody know where to find one? Also will this at least partly solve my noise problems? Thanks for any hints and advice.
Cornelis.

 

[racerone]

I ordered a couple a while back..----Got them no problem then.

 

[oldrem]

Looks like there are none available in the USA, but I did find 3 here https://www.ebay.com/itm/Johnson-Ev...ash=item1c9caa5d2c:g:KhsAAOSw1BlZQDU9&vxp=mtr

 

[rolmops]

Thank you guys. I successfully ordered one

 

[oldboat1]

any improvement? (maybe a spring project).

was thinking it may be as simple as mounting location on your transom (trolling mount may need to be lowered), or trim setting. A couple of my brackets allow trim adjustment in addition to what is available on the motor.

 

[boobie]

Edit.....

 

[thatone123]

On these outboards that do not have insulation in the hood/cowling, I install some and they get real quite. Use the foam strip (bigger the better) at least a 1/2 inch wide. It has a sticky side and is easy to use. Just cut and fit.

 

[flyingscott]

Does it have the air box on the carb.

 

[rolmops]

The boat is covered with about 2 feet of snow. So for now it is very quiet. I have tried to hang the engine a bit lower, but that did not help at all. Once my yard thaws out I will take the lower unit off and insert the rubber seal.While the lower unit is off, I will inspect the exhaust housing to see if there are any screws missing that may cause the exhaust gas and noise to escape right under the engine block. Then I will run it in a barrel to see if it is any better. Next would be the exhaust cover on the block,but I am very weary of that one ,because I might end up breaking bolts.It does have the carburetor air intake cover so that one is covered. I am toying with installing some insulation inside the cowling, but I really think that the noise is from the exhaust housing.

 

[racerone]

Are you sure you can install that seal 318996 by removing just the lower unit ?

 

[rolmops]

Are you sure you can install that seal 318996 by removing just the lower unit ?

By looking at the diagrams it seems to me that this seal goes onto the bottom of the inner exhaust seal. (It will probably have to be glued onto it somehow). It should then seal the connection between the inner exhaust housing and the lower exhaust housing. All of that is easily done with just the lower unit removed.
But I may be wrong ,in which case I will take the block of the cowling and go that way.

 

[flyingscott]

You have to pull the powerhead to replace that seal.

 

[rolmops]

1979 Johnson Outboards 9.9 - 10EL79B

EXHAUST HOUSING sec

​
The part that I have to insert is # 38 in the diagram , and by the looks of it there should be easy access once the lower unit has been removed






















































































































































































































































































Use two fingers to zoom
and move the diagram

 

[flyingscott]

Exhaust tuner seal. I believe you still need to pull The powerhead. I could be wrong.

 

[racerone]

Post #10 questions your knowledge on this procedure I think !!

 

[flyingscott]

That seal is not going to make your motor any guieter. How can you tell yours is missing they are hard to see from the bottom. Here is what is misunderstood about outboard motors. A lot of the noise you here inside the boat is actually from the intake.

 

[racerone]

Patiently waiting how this seal is changed and what the " noise reduction " outcome is.

 

[Sea Rider]

If powerhead is removed from base will need to install a new base gasket (106) gaskets dries, hardenes they even burn due to extreme hot powerhead exhaust. Re torque lower pan bolts from time to time as the gasket tends to cede, causing exhaust to scape from there producing uncomfy noise.

Happy Boating

 

[thumbnut]

That is a wet leg design. The leg fills with water after starting. They are quieter than the megaphone design which does not fill with water. Ya have to pull the powerhead to replace. If that gasket leaks it will be louder if the mid does not fill with water.

Much noise does come from the intake.

 

[rolmops]

Patiently waiting how this seal is changed and what the " noise reduction " outcome is.

I am very impatiently waiting for some warmish weather so I can get to work on this. I really want to solve my problem before the beginning of March because by then I want to do some brown trout trolling. The seal is probably just part of a more involved effort to get to the bottom of this. The alternative is a 9.9 remote controlled long shaft Tohatsu with tilt and trim. The problem there is that I do not have $3500 to spend on toys right now.