15 hp johnson water tube

[mekkamaz]

The inner exhaust housing on my J15RCNC is corroded on the water tube outlet side, and have to replace it.

The trick is, for some reason the original is old style (round at the end) and I can get my hands in a new style one, but the first one has two water tubes, (in and out), and the second one only has the inlet tube (large one). What should I do? The parts manual only shows new style inner exhaust housing in the first place, and it mention a water tube for the outlet but nothing to hold it in place , any light on this matter? does this port jus remains open? Thanks for your replies.

 

[Daviet]

Re: 15 hp johnson water tube

Is #129 what you are looking for?
http://www.ishopmarine.com/ishop/js...CatFilter=BRP&eCatSupFldr=supplier-100-005-EJ

 

[mekkamaz]

Re: 15 hp johnson water tube

Yes, as you see it also shows the square type housing, I just picked up today and the thing is this part does not has the hole for retain this tube 129, any thoughts?

 

[mekkamaz]

Re: 15 hp johnson water tube



In this pics is showed the change. also as we can see, the gasket set has this gasket for the good one...I?ve done some research and all I can find is that maybe the round ended one was used in 9.9 motors, but no luck trying to locate this or a conversion kit or something for this matter...somebody has do this before?? HELP!!!!!11

 

[raczekp1]

Re: 15 hp johnson water tube

i had in may hands 15 hp made in 1978,and this motor had square exhaust tube and only inlet water pipe

 

[mekkamaz]

Re: 15 hp johnson water tube

Thanks guys, I think nothing happens then if I let that port discharge freely. Maybe that?s why later they add the water jacket peep, right? Ha! this OMC guys....again, thanks.

 

[the machinist]

Re: 15 hp johnson water tube

There were considerable changes in these inner exhaust housings. originally they were all square for both the 9.9 & 15hp, them they made the rounded ones as a tuned exhaust for the upgraded 15hp. Finally they just put the rounded 15hp ones in all the 9.9/15s.

Like you found there also was a change in the short water outlet tube. Even the lower part of the block was different where the exhaust tube attaches, but with the newer gasket this allows the newer unit to function. The length of this short copper has been changed a couple of times. My thoughts on this copper tube, is that it diverts the water out better than just having it be dumped into the exhaust cavity. But they all fit & function in any combo.

 

[mekkamaz]

Re: 15 hp johnson water tube

Thank you machinist. Very good explanation. I?m confident now.

Best regards.