Exhaust Baffle Question

Gents,

Found this circular "baffle" loose and rattling inside the exhaust house when removing the lower unit for water pump replacement. part number 3 in this diagram. https://www.marineengine.com/parts/...&manufacturer=Johnson&section=Exhaust+Housing The legs on this disk were severely bent keeping if from snapping in (my assumption). Quite oily inside this cavity.

What does this part do? How is it replaced? How will the motor perform if it's missing? Just purchased this motor so have no personal experience of performance other than the word of the seller. Ran it in barrel prior to purchase and started and idled fine. I'm replacing the water pump due to a "weak" pee hole stream.

Evinrude J15RCNC. diagrams says this part is only used in the 15hp model.

Thanks for your thoughts.

Looking around I found this:


https://forums.iboats.com/forum/eng...7088-1982-15hp-exhaust-restrictor-plug-baffle

If it seems reusable I would put it back.

Thanks so much. That's it exactly. Seems like there wasn't a solution found in that thread. Performance will suffer seems to be the result. Logic would say it increases back pressure in the exhaust. The one I have is definitely NOT usable and it also appears that the housing would need to be removed in order to replace it. That requires a powerhead removal doesn't it? I've got an 86 model 9.9 that has the same hole with NO baffle. It's bent up pretty badly but it seems to have had 3 "legs" that snap through the aluminum hole and catch on the other side. I doubt if it stood "prowd" of the inner surface but can't know for sure.

Anyone else notice this on the 15hp models? I could certainly come up with a way to plug off the hole from the outside that would likely stay in place but wondering if anyone else has encountered this and devised solution?

I think they used it for some15s only. Not sure why. I keep em in place when they are used. Fashion something perhaps to do the same job. Probably not gonna take much creativity.

Found some pictures of the component and condition I'm describing.

I have the same issue with mine and haven't been able to find the part anywhere or a solution in the different forums. What did you end up doing with yours?

Measure opening and see if an electrical cover plug might work. McMaster-Carr might be able to supply a plug. Ya can make one. Maybe a couple of washers with a center screw and nut.

http://leeroysramblings.com/Johnson_9.9_powerhead.htm look here at the different mids.

that is exhaust silencing aid. some stainless steel wool glued in works great.

The plug is to make the meg tuner work better as it needs a bounce plate for the return wave to "stuff" the charge back into the exhaust port at higher rpms. At some point the wet leg was used on the 9.9 and the meg used on the 15's. The large hole in the mid was plugged for use with the meg tuner on the 15's. Later the large hole was deleted and both the 9.9 and 15's used the meg tuner.

Dgill said:

I have the same issue with mine and haven't been able to find the part anywhere or a solution in the different forums. What did you end up doing with yours?

Click to expand...

Here's what I did. Parts list shown and description. Seems to work fine. Didn't recognize till after assembly that the bottom washer wasn't completely covering the hole (see pics) so I'll correct that next time I have the lower unit off. I'm going to call it 95% covered !! LOL