1975 johnson 6hp water cooling

[Mark3]

Re: 1975 johnson 6hp water cooling

In your video "running a few weeks ago" your water level was clearly to low, ie: below the water pump. In the other videos the water level was above the pump were it should be.

 

[Gradywhite3535]

Re: 1975 johnson 6hp water cooling

Ok so today i realized when i cover the water outlet with my finger the underwater exhaust starts to kick in. What does this mean?

 

[emckelvy]

Re: 1975 johnson 6hp water cooling

The "blue dot" on the side of the exhaust housing is the locating "teat" for the water tube upper grommet.

One thing you could do is pull the lower unit and connect a source of water to the copper water supply tube, this will tell you if the leak is coming directly from the grommet or is just water discharge being blown thru by exhaust.

IMHO, I would just replace the gromment and be done with it. It's a critical element of the cooling system and I would want it to be correct, for peace of mind if anything else. And it's a very cheap part.

Once you have the lower unit off, grab the water supply tube and pull it out of the grommet. Then you can reach up inside the exhaust leg with a long screwdriver or set of needle-nose pliers to grab/remove the grommet. Pushing inwards on the rubber "teat" on the side will help dislodge the grommet.

Once the grommet is removed, check the hole in which is resides. I've seen 'em so built-up with salt/debris/deposits that the grommet gets sqeezed shut and the copper water pipe is squished right along with it.

If the pipe is squished, make it round again. Scrape out the hole with a screwdriver, small carbide scraper (if you've got one), or the sharp edges of a file (whatever's handy).

Spread a thin coating of Permatex No. 3 Aviation-type gasket dressing on the outside of the grommet (including the "teat"). Grab hold of the side of the grommet with your long-needle-nosed pliers and reinstall the grommet (the shoulder goes down).

Make sure you get the "teat" oriented to install thru the locating hole in the side of the exhaust housing. Once the grommet is properly seated, coat the end of the water pipe with Permatex as well, and reinstall.

The Permatex makes a good seal and provides a barrier which prevents any deposits from building-up around the grommet.

That should conclude the repairs and I expect after you reinstall the L/U and run the motor, you'll find you no longer have any leakage, & a better-functioning cooling system.

Here's a diagram which shows the grommet, same part # as the one that goes in the water pump body:

Evinrude Gearcase Parts for 1975 6hp 6504R Outboard Motor

#57 on the diagram and you can see the water tube and upper grommet in the left-side of the diagram.

HTH........ed

 

[Gradywhite3535]

Re: 1975 johnson 6hp water cooling

Yeah I'm thinking it is something to do with the grommet and water tube. I just bought a brand new one so i hope it's just not connected right. I hope I can get to it today. When taking the lower unit off should the the throttle control be on shift when taking off?

 

[raczekp1]

Re: 1975 johnson 6hp water cooling

yhis hole is water pipe gromet base.if water is flouting out by this hole it means no water is going to powerhead

 

[Gradywhite3535]

Re: 1975 johnson 6hp water cooling

So I took off lower unit and i pulled down the water tube which was in good shape. But when I looked at the top grommet, the sides seemed like it was being pinched together either by debris/sand. I need to buy a pair of long pliers tomorrow in order to grab the grommet and yank it down in order to see whats going on. I have the older water pump that still has the grommet(in good shape) that i will reuse. The old grommet shouldn't have a hole in it for the water to discharge out of the the small hole on side of exhaust housing? Is there going to be two holes like the water pump has in order to install the top grommet?

 

[Gradywhite3535]

Re: 1975 johnson 6hp water cooling

^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^

 

[F_R]

Re: 1975 johnson 6hp water cooling

My goodness, an awful lot of chatter about something I answered a couple of days ago. But that's my story and I'm sticking to it. But go ahead and replace the grommet if you think it is leaking too much. But if it were leaking so badly so as to starve the cooling system flow, the tube would have fallen out when you removed the lower unit. Maybe the other side of the cavity in the casting is busted out? Maybe you should take a looksee.

EDIT: Sorry, I didn't see the last post. Yes, the grommet fits in there exactly the same way as in the water pump housing. It isn't anything high tech.

 

[Gradywhite3535]

Re: 1975 johnson 6hp water cooling

So are you saying that its not the grommet? I thought u said if it is pouring out that it could stop the flow of the cooling system and now your saying thats not the problem lol. And when I pulled the lower unit the water tube came down with the water pump, so i don't know if it was connected or not. I think the grommet should be replaced because i feel that since the water is flowing thru that hole (which it shouldn't) that the grommet might have a slight hole or falling apart . What do you mean the other side of the cavity of the casting?This is my first time ever working in a engine so please bare with me. Thanks

 

[Gradywhite3535]

Re: 1975 johnson 6hp water cooling

^^^^^^^^^^^^^^^^^^^^^

 

[Gradywhite3535]

Re: 1975 johnson 6hp water cooling

Sorry to be annoying but i would like to hear your opinion! What do you mean by the other side of the cavity?

 

[F_R]

Re: 1975 johnson 6hp water cooling

We don't seem to be communicating. I said Don't worry about the leak, doesn't mean a thing unless it is really pouring out, which could mean a badly damaged grommet. That could result in overheating because of the water leaking out instead of going up to the powerhead". What I meant was that IF the grommet was so rotted out that all the water spilled out at that point, it wouldn't have gone on up to the powerhead to cool it. In my last post I said that IF that were the case, the water tube would have fallen out of the rotted grommet.

As for the rest, concerning the cavity, I was purely speculating in response to some other posts suggesting the area could be badly corroded. I truly doubt that such a thing I the case. I've seen hundreds, probably thousands of those type water tube setups and have never seen one corroded away that badly.

Back to my original comments, since you are so concerned and have taken it back apart, go ahead and replace the grommet. And if there still is a bit of leakage, don't worry about it. A few drops out of a gusher of water going up the tube isn't going to make any difference.
And as far as a whiff of exhaust air escaping, so what??? It is going to go on out the underwater exhaust anyway.

Finally, that is the exhaust housing. There is exhaust inside it. There also is water that has gone through the powerhead and done its job and has been discharged into the exhaust housing to cool the fire that is in there. THAT could be a portion of what you are seeing.

Bottom line: Don't worry about it. It means nothing.

 

[Gradywhite3535]

Re: 1975 johnson 6hp water cooling

I'm not trying to show up anybody or pretend like i know about boats but have you read or watch any of the videos. There seems to be alot of water coming out of that hole(well at least to me) in video B. Is that not alot if water? I never said my engine wasnt over heating. I don't know if it is or not(but it gets really hot after 3 min). And also in video A there is exhaust air coming out of the under water exhaust, whereas in video B there isn't anything coming from the under water exhaust. And now when I cover the water outlet with my finger is the only time it will come out the under water exhaust. I don't know what is causing the water not to circulate but i hope you can tell me so i can stop bothering everyone haha thankd

 

[Tim Frank]

Re: 1975 johnson 6hp water cooling

I'm not trying to show up anybody or pretend like i know about boats but have you read ....

The explanation of what is going on with your motor is in the responses that you may (or may not) have read.
FR has explained twice now....hopefully he hasn't tuned out.

1) That is not really that much water exiting the exhaust casing/housing compared to what SHOULD be pumped by the water pump. I have the exact same motor and it does not have any water exiting the "blue dot".

2) You need to ensure that the problem (which is a leak....either minor or major....that is what you must troubleshoot) is not starving the block of cooling water....that is the only real concern. If there is good cooling, I'd just go fishing, as has been suggested. As you have said, the manual states that you can check with a thermo stick....if you are fairly comfortable with these O/B you can just test with your hand, but the test stick is more precise. The point is that you MUST make sure of this or you'll ruin the motor.
Doesn't sound like you have bothered so far.

3) The exhaust housing is full of exhaust gas under a pulsing pressure, which also includes oil...it is exiting through the most convenient point, which is that "blue dot". it is also expelling water that is in the housing, and some oil. This is actually a leak from the "designed" path, and because the new exit hole is so much smaller than the intended exhaust hole, it is not as smooth a flow as it would be. Oil is clearly building up a little bit inside the housing and it looks worse than it is.

Other than the above, I am not sure what else we can offer.

 

[Gradywhite3535]

Re: 1975 johnson 6hp water cooling

So I found my problem, the upper grommet was cracked and had a hole. I been trying to put the new one in and its pretty tricky to get it up there. I will keep trying to get it there. Any tIps? I'm sure when I get this grommet up it should fix the problem and i won't have to annoy u guys for a while. Hahah