Exhaust Tube Seal Ring Install '63 75hp

[yorab]

Motor in signature. I found a new exhaust tube seal ring and I'm wondering if there are any tricks to getting it in place without damaging it. It looks like it will need to stretch quite a bit in order to get into place. Should I oil it up a bit first? Any other ideas? Thanks.

 

[F_R]

Re: Exhaust Tube Seal Ring Install '63 75hp

You are correct that it takes quite a stretch. Now, the part that I'm unsure about is I (think) it has to go on over the top end of the exhaust housing. Sorry, I am not sure on that point. (Hey it has been 30 years since I did one), But I do know it will not stretch far enough to put it over the wrong end and will break if you try.

Now you need somebody to come along that is sure which end that is.

 

[yorab]

Re: Exhaust Tube Seal Ring Install '63 75hp

Well, if somebody knows for sure, that would be great. Otherwise, I can try to remove the old seal ring and see which way is easier. I messed with it a bit already and it was pretty difficult in either direction. I'll try again tomorrow.

It's amazing how different the new seal ring looks compared to the old. I was expecting a ring that had the general oval shape of the ehaust tube but the new seal has a perfect ring shape with a perfectly circular cross section. It's basically the biggest, baddest rubber o-ring that I've ever seen.

 

[F_R]

Re: Exhaust Tube Seal Ring Install '63 75hp

yep.

 

[Evinrude Boater]

Re: Exhaust Tube Seal Ring Install '63 75hp

I've never tried but the bottom looks easier to me. The top flares out to a square shape at the adapter plate. Unless you've already got the power head removed it's a lot more work.

 

[F_R]

Re: Exhaust Tube Seal Ring Install '63 75hp

What I do remember is the route that LOOKS easiest is the wrong one. But maybe it is just my judgement that is off. And it is possible that I am remembring the 40hp. Darn Senior Moments.

 

[yorab]

Re: Exhaust Tube Seal Ring Install '63 75hp

Yeah, I'll try to get the old seal off today. If the old seal doesn't break, then I'm hopeful that the new seal can be installed from that side. I'll post back so others have a sure answer in the future.

 

[Evinrude Boater]

Re: Exhaust Tube Seal Ring Install '63 75hp

Do you really need to replace that seal? If not, why bother breaking it if it still works just fine?

 

[yorab]

Re: Exhaust Tube Seal Ring Install '63 75hp

When I last used my motor a while back, I had exhaust gases under the cowl. I'm not certain that they were passing by the exhaust tube seal, but it's a good guess. I've spent the last 3 years (on and off) rebuilding my motor so I don't see any harm in replacing that seal so that I don't have to take everything apart later if it turns out to be a faulty seal. This is especially important if the seal must install over the adapter plate because I would need to take the powerhead back off again. Just some peace of mind for myself I suppose...

 

[yorab]

Re: Exhaust Tube Seal Ring Install '63 75hp

So I just tried to put the seal over the top end. The top end of my exhaust tube flares out to a square-ish shape. Bad news for me. The ring broke.

I'm not sure if it was due to the fact that the seal was an old rubber seal or if I put it over the wrong end. The bottom of the exhaust tube has a much skinnier profile but it is much longer that the top end. I guess I'll try the bottom next time if I can find another seal ring. The first ring wasn't easy to find.

I'll post back with the outcome.

 

[yorab]

Re: Exhaust Tube Seal Ring Install '63 75hp

What do y'all think about heating the ring first? That may make it a bit more flexible.

 

[yorab]

Re: Exhaust Tube Seal Ring Install '63 75hp

I measured the circumference of the top and bottom of the exhaust tube and the top is definitely smaller even though it may not seem like it.

I also found two more seal rings. One seemed to be a bit brittle so the guy threw it in for free. I tried the brittle one first. Again, it broke when I tried to go over the square-ish top part of the exhuast tube.

I then tried the last ring. Success! It did stretch over the top end of the tube. I had to have some help in order to make sure that the stretching occurred over the entire length of the ring and not just in one spot. Even with two people, it was still a PITA. But I can say that the ring should go over the top of the tube.

 

[F_R]

Re: Exhaust Tube Seal Ring Install '63 75hp

I thought so, but thanks for confirming that.

If you still get exhaust under the cover, make sure the foam seal is on top of the water pump housing. That'll do it, big time.

 

[yorab]

Re: Exhaust Tube Seal Ring Install '63 75hp

So here are a few pictures of the undeformed seal. It is made of some kind of foam rubber covered by a thin rubber skin. If you ever need to replace one, have help so that you can stretch the seal ring evenly over its entire length.