1982 15hp exhaust restrictor plug baffle

[Gazman67]

I have a J15RCNC.

Service manual calls for part number 325334 restrictor plug in the big hole in center of pic.


States, "loss of power if not installed". This part is no longer available.


Can I make one? Does it completely occlude the large hole or sit proud one side or the other allowing "some" exhaust flow around it? Increased back pressure I presume and it's only called for on 15hp, not the 9.9.

Anyone have experience with this?

I'm new to outboards. Rebuilt this after finally troubleshooting a loose reed stop. It allowed the reed to get "nibbled" on, taking out top cylinder from firing.

Thanks
Chris

 

[kodibass]

I'l look I have several older junked 15 hp, see whats in there heck I never noticed before got me curious now too.

 

[Gazman67]

Thanks.

Put her together without anything in the hole.

Fired up nice. Still would like to know if this makes a difference on the 15hp.

 

[Chinewalker]

I've worked on a lot of those 9.9/15 models and never noticed anything in that spot.

 

[kbait]

X2 ^

 

[Gazman67]

Good to know. Thanks.

Maybe this was unique to the 1982 as this was early in the change to tuned/round exhaust.

Don't know if later years had same hole configuration or was filled in or machined differently.

Maybe it was a solution to use up 9.9 exhaust housings. I'll have to look for exhaust housing pics of 15hp manufactured in later years.

 

[pilot1950]

New to the forum but found this thread doing a search so bringing it back up. I've got the same issue. Motor purchased used and former owner says there were no issues. Not sure I trust that assessment after doing a more thorough examination. I've not had it in the water yet aside from running in a barrel so can't speak to the performance. In the process of changing water pump and found this issue. Mine was rattling loose inside the housing with 2 of the three legs broken off. Since if clearly wasn't performing it's function I managed to twist / bend it enough to get it through the hole. I've read the above text and comments. I also have a 86 model 9.9 that has the same hole in the housing but nothing in it. I bought this motor new (the 9.9) so I know that nobody has been in there. I'm going to assume the designers had a reason for it to be there (likely increase back pressure on the 15, maybe at high speed) so want to replace the function at least. Would like to avoid pulling the power head and entire housing to install from the inside so wondering if anyone has found a simple solution to plug the hole securely from the outside as seen in the picture above. Would appreciate your ideas and experience. Thanks.

 

[GA_Boater]

New to the forum but found this thread doing a search so bringing it back up.

Start your own thread. After 90 days of inactivity threads can only be reopened by the thread starter for updates. That was almost 6 years ago, so now it's closed.